Insect Ecology and IPM Including Beneficial Insects 1
Course No. : ENTO-242 Course Title: Insect Ecology and Integrated Pest Management Including Beneficial Insects. Course Credit: 3(2+1) Teaching Schedule (Theory):
Lecture Topic No. 1 Insect Ecology: Definition – Importance of ecology and its scope. Environment : Its components 3 Effect of abiotic factors – temperature, moisture, humidity, rainfall, light. Atmospheric pressure and air currents. 4 Effect of biotic factors-food competition natural and environmental resistance. 5 Concepts of balance of life in nature, biotic potential and environmental resistance. Causes of pests outbreaks in agro-ecosystem. 6 Pest surveillance and pest forecasting. 7 Categories of pests. 8 IPM-Definition, importance, concepts, principles and tools of IMP. 9 Practices, scope and limitation of IPM. 10 Host Plant Resistance. 11 Cultural, mechanical. Methods of Pest control. 12 Physical, Legislative. Methods of pest control. 13 Biological methods of pest control.(Parasites, predators) 14 Microbial methods of pest control (Bacteria, Fungi, Viruses Nematodes, weed Killers.) 15 Chemical control- importance, hazards and limitations. 16 Classification of insecticides-Inorganic & organic 17 Mode of action of insecticides. 18 Novel insecticides IGR, chitin synthesis inhibitor, Juvenile Hormones mimic, ecdysone antagonistic 19 Toxicity of insecticides.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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20,21 Formulations of insecticides, pesticide application equipment &22 Recent methods of pest control- repellents, antifeedants attractants, gamma radiation, genetic control (Transgenic crops) 23 Semio-chemicals 24 Insecticide Act 1968, important provisions. 25 Phytotoxicity and compatibility of insecticides. 26 Symptoms of poisoning, first aids and antidotes. 27 Mass multiplication techniques 1. Trichogramma 2. Cryptolaemus (coccinellids) 3. Epiricania melanoleuca 4. Kopidosoma Koehleri 5. Chrysopids. 28 Important group of microorganisms. Bacterial- mass multiplications (Bt), Pseudomonas. Fungi – mass multiplication Verticillum lecanii, Beaveria, Metarrhizum. Viruses – HaNPV, SlNPV, Mass multiplication. 29 & 30 Sericulture /Lac culture / apiculture. 31 Non-insect pests: mites, rodents, birds, and nematodes, snails. 32 Vermiculture: - importance, species of vermicompost, morphology, techniques of vermicompost production, use of Vermicompost in agriculture.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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INSECT ECOLOGY
The term ecology was coined by a German biologist Ernst Haeckel (1869). The term ecology is derived from the Greek word “oikos” means “house or place to live” & “logous” means “the science of” or “the study of”. Thus literally ecology is the study of earth’s household comprising of the plants, animals, microorganisms and people that live together as interdependent components.
Definition of Ecology
Ecology: - It is the science which deals with the study of relationship of organisms with their environment including both biotic & abiotic factors. Insect Ecology: - The science which deals with the study of relationship of insects to their environment.
Terminology Related to Ecology Auto ecology: - Study of an individual organism, its behavior and influence of environment on its life cycle. Synecology: - Study of groups of organism which are found as unite called community ecology. Habitat ecology: - Study of habitat and its effects on the organisms. Ethology: - Study of behavior of organisms under natural condition. Habitat: - It is the place where the organism lives. Population: - denotes groups of individuals of any kind of organism. Community: - in the ecological sense includes all the populations of a given area. Ecosystem: - A self-containing system they are composed of living organisms and the nonliving environment where continuous exchange of matter and energy takes place. Biome: - The grouping of communities that have similar structure composed of ecosystem of similar vegetation type. Biota: - Fauna and flora of a particular habitat are together called biota. Biosphere: - It is the largest ecosystem which includes all living organism on earth interacting with physical environment. Ectone: - Some communities which are considered to be transitional between two biomes called Ectone. Inquilines: - An animal lives in the habitat of another one with sharing its food. Phoresy: - A commensalistic relationship among the organisms in which one kind of organism attacks to another thereby gains mode of transportation.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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ENVIRONMENT: ITS COMPONENTS
The term environment entomologically means “Surroundings”. Environment is a complex of living and non-living factors which surrounds on organisms. Environment: - An environment is anything which surrounding to individuals that may influence its change to survive and multiply.
Components (Factors) of environment:-
Following components of environment affect or influencing on insect population. A) Abiotic Factors: (Physical/non-living /Density independent factor) 1.) Climatic factor :- i) Temperature ii) Rainfall iii) Humidity (Moisture) iv) Air current (Wind) v) Light vi) Atmospheric pressure 2.) Topographic factor: - i) Mountains ii) Sea, Ocean, River iii) Soil
B) Biotic factors: (Living /Density dependent factor) 1.) Food (Nutritional factor) 2.) Competition (Interspecific & Intraspecific Competition) 3.) Natural enemies (Predators, Parasite & Pathogen)
Abiotic Factors (Density independent factors)
Temperature Insects are the cold blooded animals; they do not have mechanism to regulate body temperature called poikilothermic. Insects survive at specific optimum temperature - Upper lethal limit i s 40- 50oC (even up to 60oC survival in some stored product insects) & Lower lethal limit - Below freezing point e.g. snow fleas. At low temperature (winter) insect takes more days to complete a stage (larval or pupal stage) Larva, pupa commonly undergoes hibernation in winter. At high temperature (summer) it takes less than to complete a stage. Eggs undergo aestivation in summer. Temperature effects on fecundity, migration & rate of development of insects. E.g. i) Grasshopper lays 20-30 times more eggs at 32oC compared to 22oC, ii) Oviposition of bed bug inhibited at 8-10oC, iii) Thrips give few eggs at 8°c & more at 20-30°c, iv) Larval period of sugarcane internode borer is very short in summer & prolonged in winter & v) Swarm migration of locust occurs at 17-20oC.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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Rainfall Heavy rainfall has adverse effect on small insects like aphids, Jassids, thrips, white fly, mealy bugs, diamond back moth (DBM) and scale insects etc. which are washed out from plants & killed in flooded soil. Rainfall also effect on the abundance of insects. Rainfall is essential for adult emergence of cutworms and RHC.
Humidity / (Moisture) It is essential for physiological activities like metabolic reactions and transportation of salts in insects. Insect get die when water content increases or decreases termed as lethal wetness or lethal dryness. Moisture scarcity leads to dehydration and death of insects. High humidity causes development / Encourages of disease causing pathogens on insects (fungi). e. g. White halo fungus Verticillium lecanii on coffee green scale requires high RH for multiplication and spread, Termites prefer high humidity 90-95% RH Humidity also effect on fecundity & normal development of insects. E.g. Locust does not lay eggs if there is no sufficient moisture. It mature quicker & give more eggs at 70% relative humidity, Low RH in rainfed groundnut crop induces leaf mines incidence.
Air current (Wind) The disposal of insects to great extent depends upon wind. It interferes with feeding, mating & oviposition of insects. Many insects fly with the air current & get transfer from one place to other. Many of them die by falling in rivers or sea. Many insects are known to spread in new countries through air currents. Large number of aphids has been found after a strong wind & many of them are destroyed by falling in the sea & rivers etc. Thus air current also play an important role in natural control of insects.
Light Light plays an important role in growth, development & survival because it is prime source of energy in all organisms. Light control locomotive activities of insects by direct action this phenomenon is called as Phytokinesis. The movement of animal in response to light called phototaxis. The response of organism towards the length of day light called as Photoperiodism. Photo period influences induction of diapause (a resting stage) in most of the insects E . g . Short day species- mulberry silk moth & Long Day Species- Pink bollworm.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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Some insects are active in night (Nocturnal), Some are active during the day (diurnal) & Some active during dawn and dusk (Crepuscular). In many insects oviposition is stimulated by exposure to light or darkness. E.g. Fruit flies lays eggs in light, Lepidopterans like cotton bollworm, Red hairy caterpillar (RHC) oviposit in dark.
Atmospheric pressure The insects are more affected in low atmospheric pressure than in high atmospheric pressure. The phototrophic insects are more active during periods of high atmospheric pressure. The activities of some insects are directly influenced by pressure. E.g. due to the low atmospheric pressure a chances of rain increased resulting the emergence of ants.
Topographic factors Major topographic factors like mountain, rivers, sea are act as physical barriers to the spread of insects. Lake & ponds affect the nature of insects of that region. Water current - Larva of mosquitoes & beetles are able to live only in standing water & running water is preferred by Dragonfly and Caddis flies. Soil type - Wire worm, multiplies in heavy clay soil with poor drainage whereas termites, white grubs & cut worm prefer light, loamy soil.
Biotic Factors (Density dependent factors)
Food (Nutritional factor) Insects are heterotrophic hence they cannot synthesize their own food they depend on plants for food. The quantity and quality of food/nutrition plays important role in survival, longevity, distribution, reproduction and speed of development Quantity of food - Short supply of food causes intraspecific and interspecific competition. Quantity of food - This depends on nutritional availability of plants. Crop varieties/species differ in nutritional status which affects insects.
Competition Insect species are likely to be competing with one another or with members of another species for limited resources like food, mates, suitable site for oviposition or pupation. Such competition operates whenever the population is increasing and the resources are limited. a) Intraspecific competition: When members of population of the same species compete for resources. Examples are as follows; i) Cannibalism in American bollworm larvae,
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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ii) Cannibalism in later stage grubs of Chrysopid, iii) Crowding in aphids result in alate (winged) form for migration, iv)) Reduction in fecundity (egg laying) in rice weevil during overcrowding. v) Crowding in honeybees leads to swarming. b) Interspecific competition: This is the competition occurring between members of two or more species. Two or more competing species with identical requirements cannot coexist in a same place for a long time. The elimination of one species by another as a result of interspecific competition. It gives by Russian scientist G. F. Gause called competitive exclusion principle or Gause’s hypothesis / principle. E.g. i) Accidental introduction of oriental fruit fly into Hawaii eliminated by Mediterranean fruit fly & ii) Trichogramma & Crysoperla compete for Helicoverpa eggs in cotton.
Cannibalism: - It is the phenomenon where the insects feed on the individuals of the same species when crowding is occurring. Colonization: - Grouping of free living individuals to form colonies to have better protection from natural enemies or environmental conditions for improved utilization of food. Aggregation: - Tendency of congregating in large numbers than normal distribution for mating, food etc.
Natural enemies Every insect has a number of natural enemies in the nature viz; parasitic insects, predatory insects, mites, spider, birds, mammals, reptiles, fishes & diseases causing fungi, bacteria & viruses. They keep the insect population in check and thus natural balance within limits is almost always maintained. Predators: Predators are free living organisms that feed on l i v i n g insects & consume more than one individual during their lifespan. Major insect predators are as follows; Lady bird beetle (Coccinellids) - Feed on aphids & leaf hoppers. Green lace wing (Chrysoperla spp.) - Feed on aphids & other sucking pests. Mantid, Dragon fly & Syrphid fly - Feed on different insects.
Parasitoid: An insect parasite of an arthropod that is parasitic in its immature stage killing the host in the process of development and adults are free living. Major insect parasitoids are as follows; Trichogramma spp. - Feed on Sugarcane borers & Cotton bollworms. Apanteles flavips - Feed on lepidopteran larvae. Epiricania meloneuca - Feed on sugarcane pyrilla. Capidosoma koeheleri & Chilonus blackberni - Feed on potato tuber moth.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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Parasites: Parasites are organisms which live on other organisms for getting food & shelter. The association of parasite and host known as parasitism. A parasite weakens or kills the host while feeding requires only one part of one host to reach maturity. E.g. ticks, mites, Protozoa, Nematodes and other arthropods. Pathogens: Disease causing microorganisms called as pathogens. Certain fungi bacteria & viruses cause disease in many insects & reduce their population in nature. The important microorganisms which cause disease in insects are as follows; Fungi - E.g. Verticillium lecanii (White halo fungus) cause disease in mealybugs & aphids, Beaveria bassiana (White muscardine fungus) cause disease in lepidopteran larvae & Metarhizium anisopliae (Green muscardine fungus) in coconut rhinoceros beetle. Bacteria - E.g. Bacillus thuringiensis effective against lepidopteran larvae & Bacillus popilliae attacking on beetles. Virus - E.g. HaNPV (Helicoverpa armigera nuclear polyhedrosis viruses) against American bollworm. & SlNPV - (Spodoptera litura nuclear polyhedrosis viruses) against tobacco leaf eating caterpillar.
Other Natural Enemies: Frog, Toad, reptiles, birds, rats, bears, snakes & lizard
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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Environmental Resistance & Pest Outbreaks
Agroecosystem - Any ecosystem largely created and maintained to satisfy a human want or need. o It is not a natural ecosystem but is man-made. o Agroecosystem is the basic unit of pest management - a branch of applied ecology. o A typical agroecosystem is composed of; i) More or less uniform crop-plant population ii) Weed communities iii) Animal communities (including insects) iv) Macrobiotic communities v) and the physical environment the react with.
Balance of Nature - Definition - “The maintenance of more or less fluctuating population density of a given organism over a period of time with in certain definable upper and lower limits by action of abiotic and biotic factors”. Or a tendency of population density of all species in a same area to maintain a constant number of individuals in the physical environment. The concept of Balance of Nature was given by Smith in1935. . In unmanaged ecosystems, a state of balance exists or will be reached, that is species interact with each other and with their physical environment in such a way that on average, individuals are able only to replace themselves. Each species in the community achieves a certain status that becomes fixed for a period of time and is resistant to change which is termed as the balance of nature. . When man begins to manage creating new ecosystem ( agroecosystem) where natural ecosystem existed previously, the balance is altered. The exceptionally strong forces react in opposition to our imposed change toward a return to the original system (e.g. outbreak of a pest is one of the forces). So, insect pests are not ecological aberrations. Their activities counter wants and needs of human populations.
Factors that determine insect abundance:-
1) Biotic potential - It is the innate ability of the population to reproduce and survive. It depends on the inherited properties of the insect i.e., reproduction and survival. Potential natality is the reproductive rate of the individuals in an optimal environment. Survival rate depends on the feeding habits and protection to young ones.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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Generally insects with high reproductive rate tend to have low survival rate and vice versa. Insect pests with high reproductive rate and low survival rate are called r strategists named after the statistical parameter r, the symbol for growth rate coefficient. E.g. Aphids. K strategists reproduce slowly but effectively compete for environmental resources and so their survival rate is high. (K letter denotes flattened portion of growth curve) e.g. Codling moth of apple. Birth rate or natality is measured as the total number of eggs laid per female per unit time. Factors determining birth rate are fecundity, fertility and sex ratio. Death rate or mortality denotes the number of insects dying over a period.
2.) Environmental resistance - It is the physical and biological restraints that prevent a species from realizing its Biotic potential.
Environmental resistance may be of 2 types. 1. Biotic factors - includes a) Competition (interspecific and intraspecific) b) Natural enemies (predators, parasites and pathogens) 2. Abiotic factors -Temperature, Light, Moisture & water. ‘K’ Mortality - it is that factor existing in natures that are responsible for mortality of the insects.
Population dynamics:-
Insect populations grow in two contrasting ways. 1. J- shaped growth form 2. S- Shaped or sigmoid growth form
In the J - shaped growth form, the population density increases in exponential or geometric fashion. Populations with this kind of growth form are unstable. Their reproductive rate is high and survival rate is less and so they are r strategists. Factors other than density regulate the population. (e.g.; Aphids). In the S-shaped growth pattern the rate of increase of density decreases as the population increases. Their reproductive rate is less and survival rate is more. So they are K strategists. This pattern has more stability since the population regulates itself. (E.g. Hymenopterans).
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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Life table: Life tables are tabular statements showing the number of insects dying over a period of time and accounting for their deaths. Life table is a numerical aid used in the study of insect population to record in a systematic fashion. There are two types of life table; 1.) Age specific (Horizontal) life table - It is based on the observations made on single generation in different region. 2.) Time specific (Vertical) life table - It is based on the observations made on overlapping/multiple generation. Uses of life table : i.) Number of generations per year of an insect can be known. ii.) Age of different life stages can be known. iii.) Key mortality factor & critical stages affected can be known. iv.) Population models can be developed from life table. v.) Pest surveillance, pest forecasting & prediction of pest can be possible. vi.) It is possible to regulate beneficial processes like parasitism, predation, inter & intraspecific competitions etc.
Causes of pests outbreaks in agro-ecosystem
Pest outbreaks: - The phenomenon of sudden increases in pest population due to the effect of different biotic & abiotic factors.
Activity of human beings which upsets the biotic balance of ecosystem is the prime cause for pest outbreak. The following are some human interventions - Reason for outbreak
1.) Bringing forest area under cultivation or destruction of forest. 2.) Destruction of natural enemies of pests. 3.) Intensive and Extensive cultivation. 4.) Introduction of new varieties and crops. 5.) Improved agronomic practices. 6.) Introduction of new pest in new area or environment. 7.) Accidental introduction of pests from foreign countries (through air/sea ports) 8.) Large scale storage of food grains 9.) Lack of adopting IPM strategies. 10.) Resurgence of sucking pests.
Bringing forest area under cultivation or destruction of forest. The insects feeding on the forest trees & plants in the forest are driven to neighboring areas where they may infest the cultivated crops and become new pests.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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Destruction of natural enemies of pests. Due to excess use of insecticides, natural enemies are killed. This affects the natural control mechanism and pest outbreak occurs, e.g. Synthetic parathyroid insecticides kill natural enemies. Intensive and Extensive cultivation. Monoculture (Intensive) leads to multiplication of pests. Extensive cultivation of susceptible variety in large area - No competition for food multiplication increases e.g. Stem borers in rice and sugarcane. Introduction of new varieties (Strain) and crops. New plant may serve as new host for some of the insect species. Mostly improved strains of crop plants are susceptible to pests whereas character near to their wild parents is resistant to pest attack. Varieties wi t h favorable physiological a n d morphological f a c t o r s cause multiplication of insects. E.g. Succulent, dwarf rice varieties favors to leaf folder, Cambodia cotton favors stem weevil and spotted bollworm & Hybrid sorghum (CSH 1, HB1) favors shoot flies and gall midges. Improved agronomic practices. Application of more nitrogenous fertilizers leads to crop growth which increase stem borer incidence in rice & sucking pests in cotton. Closer planting in rice increase incidence of brown plant hoppers & leaf folder. Introduction of new pest in new environment. Pest multiplies due to absence of natural enemies in new area. E.g. Apple wooly aphid multiplied fast due to absence of Aphelinus mali (Parasite) in Nilgiri hills. Accidental introduction of pests from foreign countries. Diamondback moth on cruciferous crops, Potato tuber moth on potato, Cottony cushion scale on wattle tree, Wooly aphid on apple, Psyllid on subabul & Spiralling whitefly on most of horticultural crops. Large scale storage of food grains. Serve as reservoir for stored grain pests & Rats found in underground drainage. Resurgence of sucking pests. Definition: - Tremendous increase in pest population brought about by insecticides despite good initial reduction in pest population at the time of treatment called resurgence. Deltamethrin, Quinalphos & Phorate cause resurgence of BPH in rice, Synthetic pyrethroids cause resurgence of Whitefly in cotton & Carbofuran cause resurgence of Leaf folder in rice.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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Pest surveillance and pest forecasting Pest Monitoring - It is the estimation of changes in insect distribution and abundance, information about insects & life history, influence of biotic & abiotic factors on pest population.
Pest Surveillance - It refers to the constant watch on the population dynamics of pests, its incidence and damage on each crop at fixed intervals to forewarn the farmers to take up timely crop protection measures. There are three basic components of pests surveillance; i.) Determination of the level of incidence of the pest species, ii.) Determination of the loss caused by the incidence & iii.) Determination of the economic benefits, the control will provide. Objective of pests surveillance 1.) To know the existing and new species of pests. 2.) To assess the pest population and damage at different growth stage of crop. 3.) To study the different weather parameters on pests. 4.) To study changing pest status (Major & minor). 5.) To assess natural enemies and their influence on pests. 6.) To study effect of new cropping pattern and varieties on pest.
Pest forecasting - Forecasting of pest incidence or outbreak based on information obtained from pest surveillance. Uses of pest forecasting - i.) Predicting pest outbreak which needs control measure. ii.) To know the suitable stage at which control measure gives maximum protection. Types of pest forecasting - 1.) Short term forecasting- one or two crop seasons. 2.) Long term forecasting- cover large areas & based on weather conditions. Pest forecasting comprises following three main points: - . Quantitative measurement of population of pest on ecological zones. . Study of life history of the insect pest. . Study of fluctuation in pest population due to natural enemies & other factors.
Survey: - Conducted to study the abundance of a pest species. Types of survey - 1.) Roving survey 2.) Fixed plot survey
Roving survey o Assessment of pest population/damage from randomly selected spots representing larger area o Large area surveyed in short period o Provides information on pest level over large area
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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Fixed plot survey o Assessment of pest population/damage from a fixed plot selected in a field. o The data on pest population/damage recorded periodic from sowing till harvest. o Qualitative survey - Useful for detection of pests. o Quantitative survey - Useful for enumeration of pest.
Sampling technique - 1.) Absolute - To count all the pests occurring in a plot 2.) Relative - To measure pest in terms of some values which can be compared over time and space e.g. Light trap catch, Pheromone trap. Methods of sampling - a.) In situ count - Visual observation on number of insects on plant canopy (either entire plot or randomly selected plot). b.) Knock down - Collecting insects from an area by removing from crop and (Sudden trap) counting (Jarring). c.) Netting - Use of sweep net for hoppers, odonata, grasshopper. d.) Narcotized collection - Quick moving insects anaesthetized and counter. e.) Trapping - Light trap - Phototropic insects, Pheromone trap - Species specific, Sticky trap - Sucking insects, Bait trap - Sorghum shoot fly & Fishmeal trap Emergence trap - For soil insects. f.) Crop samples - Plant parts removed and pest counted e.g. Bollworms
Decision Making/Concept of injury level Population or damage assessed from the crop compared with ETL and EIL. When pest level crosses ETL, control measure has to be taken to prevent pest from reducing EIL. Concept of injury level was given by Stern et al. 1959. Economic Injury level (EIL): - The lowest pest population density that will cause economic damage. Also defined as a critical density where the loss caused by the pest equals the cost of control measure. Economic Threshold Level (ETL) or Action threshold: - The pest population density at which control measures should be applied to prevent the economic yield loss of crop. ETL is always less than EIL. General equilibrium position (GEP):- The average density of a pest population over a long period of time, around which the pest population tends to fluctuate due to biotic and abiotic factors and in the absence of permanent environmental changes. Damage boundary (DB):- The lowest level of damage which can be measured. Provides sufficient time for control measures.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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CATEGORIES OF PESTS Pest- Derived from French word ‘Peste’ and Latin term ‘Pestis’ meaning plague or contagious disease. Pests include insects, nematodes, mites, snails, slugs, etc. and vertebrates like rats, birds, etc. Depending upon the importance, pests may be agricultural forest, household, medical, aesthetic and veterinary pests. Definition - Pest is any animal, pathogen, insects which cause damage to man, his animals & crops. Or Pest is any animal which is noxious, destructive or troublesome to man or his interests. Economic Pest: - The pest which causes more than five percent economic yield loss. CATEGORIES OF PESTS A.) According to frequency of occurrence: - 1.) Regular pest: Certain pests occur most frequently on crop form close association with particular crops. E. g. Gram pod borer, Thrips on chilies, Aphids on cotton, soot & fruit borer on Brinjal & bhendi & Epilachna beetle on Brinjal. 2.) Occasional pest: Certain pests occur rather infrequently on crop & there is no close association with particular crops. E. g. Caseworm on rice, Mango stem borer. 3.) Seasonal pest: Occurs during a particular season every year. E. g. Grasshoppers on safflower in kharif, Red hairy caterpillar on groundnut in kharif, White grub 4.) Persistent pests: Occurs on the crop throughout the year and is difficult to control. E. g. Chilli thrips, mealy bug on guava 5.) Sporadic pests: Pest which occurs in few isolated localities during some period. E. g. Coconut slug caterpillar, Rice ear head bug. B.) According to intensity of pest or Based on level of infestation : - 1.) Epidemic: Sudden outbreak of a pest in a severe form in a region at a particular time. E. g. Brown plant hopper in Tanjore, Red hairy caterpillar in Madurai, 2.) Endemic: Occurrence of the pest in a low level, regularly and confined to particular area. E.g. Rice gall midge in Madurai, White grubs on sugarcane in Kolhapur district, Groundnut in sangali, Rice stem borer in Raigad district. C.) According to losses caused by pest or According To EIL, GEP And DB: - 1.) Negligible: If the insect causes less than 5% yield loss. 2.) Minor pest: If the insect causes 5-10% yield loss. E.g. Rice hispa, Ash weevils. 3.) Major pest: If the insect cause more than 10% yields loss. E.g. Cotton jassid, Rice stem borer. 4.) Key pest: Most severe and damaging pests & GEP lies above EIL always hence the environment must be changed to bring GEP below EIL. E.g. Cotton bollworm, Diamond back moth. D.) ‘r’ pest: small size insects having strong dispersal & more host finding ability
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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Host Plant Resistance
Definition: - The ability of some varieties to produce good quality yield than ordinary varieties at the same level of insect population. R.H. Painter (1968): He defined as relative amount of heritable quality possessed by a plant which influences the ultimate degree of damage done by the insect. He also referred as a Father of HPR. R.H. Painter (1936, 1941) classified the mechanisms of resistance into (i) Non preference (ii) Antibiosis (iii) Tolerance.
Mechanism of Insect Resistance: -
Antixenosis (Non-preference): - It results from some morphological characters like- i) Absence of attractant, ii) Presence of repellent and allelochemic / morphological characters. It is used to denote the group of plant characters and insect responses that keep away an insect from using a particular plant (or) variety, for oviposition, food (or) shelter (or) combination of the three (Painter, 1951). It is proposed by Kogan and Ortman (1978). Morphological characters include plant character such as (1) trichomes, (2) surface waxes, (3) hardiness of plant tissues, (4) thickening of cell walls and (5) cuticle, (6) rapid proliferation of tissues, (7) colour, and shape etc. E.g. Trichomes in cotton - resistant to whitefly, Wax bloom on carucifer leaves - deter feeding by DBM Plant, shape and colour also play a role in non-preference, Open panicle of sorghum - Supports less Helicoverpa.
Antibiosis: - Adverse effect of host plant on the biology of insects. This is due to the presence of toxic metabolites - alkaloids, glucosides, anions Absence / insufficiency of essential nutrients unbalanced proportion of nutrients Presence of antimetabolites that renders some essential nutrients unavailable to insect. Presence of enzymes inhibits normal process of food digestion and consequently utilization of nutrients.
Salicylic acid Rice stem borer Gossypol (Polyphenol) Helicoverpa armigera (American bollworm) Sinigrin Aphids, Myzus persicae Cucurbitacin Cucurbit fruit flies DIMBOA (Dihydroxy methyl Against European corn borer, Ostrinia benzoxazin) nubilalis
Tolerance: - ability of host plant to withstand and give good quality yield even if the sufficient infestation of insects are observed. Tolerance has no adverse effect on the insects. Known component of this form of resistance includes. i) General vigour of plant, ii) Compensatory plant growth in individual plant / population, iii) Wound healing, iv) Mechanical supports in tissue and organs v) Changes in photosynthate partitioning.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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Avoidance or Escape: - Escape of a variety from insect attack either due to earliness or its cultivation in the season where insect population is very low. Major gene resistance: Controlled by one or few major genes (vertical resistance).
Minor gene resistance: Controlled by many minor genes. The cumulative effect of minor genes is called adult resistance or mature resistance or field resistance. Also called horizontal resistance.
Advantages of HPR as a component in IPM Specificity: Specific to the target pest. Natural enemies unaffected Cumulative effect: Lasts for many successive generations Eco-friendly: No pollution. No effect on man and animals Easily adoptable: High yielding insect resistant variety easily accepted and adopted by farmers. Less cost. Effectiveness: Res. variety increases efficacy of insecticides and natural enemies Compatibility: HPR can be combined with all other components of IPM Decreased pesticide application: Resistant varieties require less frequent and low doses of insecticide. Persistence: Some varieties have durable resistance for long periods
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 18
INTEGRATED PEST MANAGEMENT (IPM) History of IPM: - Michel bacher and Bacon (1952) coined the term “integrated control”. Stern et al. (1959) defined integrated control as “applied pest control which combines and integrates biological and chemical control” The idea of managing pest population was proposed by Geiger and Clark (1961) who called this concept as “protective population management”. Geier (1966) coined the term “pest management”. Council on Environmental Quality (CEQ, 1972) gave the term “Integrated Pest Management” IPM Working Group (IPMWG-1990) was constituted to strengthen implementation of IPM at international level. In 1997, Smith and Adkisson were awarded the World Food Prize for pioneering work on implementation of IPM. NCIPM: National Centre for Integrated Pest Management at Faridabad (Near Delhi) (1988). In 1967 a broader definition was adopted by FAO (Food Agricultural Organization, Italy- Rome) Panel of experts as - Definition: - ‘It is the pest management system in context of associated environment and population dynamics of pest species utilize all the suitable techniques and methods in as compatible manner as possible and maintains pest populations at level below those causing economic injury.’ Need for Pest Management - 1. Development of resistance in insects against insecticides e.g. OP and synthetic pyrethroid resistance in Helicoverpa armigera. 2. Outbreak of secondary pest e.g. Whiteflies e m e r g e d as major p es t when spraying insecticide against H. armigera. 3. Resurgence of target pest e.g. BPH of rice increased when some OP chemicals are applied. 4. When number of application increases, profit decreases. 5. Environmental contamination and reduction in its quality. 6. Killing of non-target animals and natural enemies. 7. Human and animal health hazards. Objectives of pest management 1. To reduce pest status below economic injury level. Complete elimination of pest is not the objective. 2. To manage insects by not only killing them but by preventing feeding, multiplication and dispersal. 3. To use ecofriendly methods, which will maintain quality of environment (air, water, wild life and plant life) 4. To make maximum use of natural mortality factors, apply control measures only when needed. 5. To use component in sustainable crop production.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 19
Principles of Pest Control: 1. Identification/Monitoring insect pests and natural enemies of pest. 2. Insect classification and life history. 3. Understanding the pest population dynamics & Concepts of injury levels. 4. Understanding the agro-ecosystem. 5. Knowledge of introduced pest. 6. Economics of the pest control. 7. Consumers pressure. 8. Preventive control. 9. Knowledge of various pest control methods/Integration of pest control tactics. 10. Extension Education. Advantages/Importance/Significance of IPM :- 1) It minimizes residue & toxic hazards. 2) It helps to minimize the development of pesticide resistance in the pest. 3) It gives scope to biological control & bio-agents. 4) It is easy to adopt. 5) It is cheaper & most efficient way of utilizing chemical insecticides. 6) It is ecologically beneficial to both human & animals. 7) Export of agricultural commodities. Limitations/Disadvantages of IPM: - 1) Lack of planning in national economic planning. 2) Lack of IPM information to the farmers. 3) Pesticide industries create a situation that chemicals give effective control of pest
Tools/Methods of IPM Preventive methods of IPM include the following a. Natural enemies b. Host plant resistance c. Legal control (Plant Quarantine) d. Cultural control Curative methods of IPM include the following a. Physical methods b. Mechanical methods c. Chemical methods d. Biological methods e. Insect Growth Regulator (IGR)
Preventive methods can be used, irrespective of the level of pest incidence. It can be followed as a routine, even if the pest is at a low level. Curative methods have to be followed only when the pest attains economic threshold level (ETL).
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 20
Different Methods of Pest Control
Natural Control Artificial Control (Applied control/ Tools of IPM)
Abiotic factors Biotic factors (Density independent) (Density dependent)
(1. Food 2. Shelter 3. Natural Enemies)
Climatic Topographical
1)Mountains 2)Soil properties 3) Ocean (Water resources) 4) Deserts
1) Temp 2) Humidity 3) Rainfall/ Moisture 4) Air 5) Sunlight etc
1. Cultural control 2. Mechanical control 3. Physical control 4. Biological Control 5. Legal Control 6. Chemical Control
Recent trends in pest control
1. Ionizing /radiation 2. Chemosterilants 3. Pheromones 4. Genetic manipulation 5. Insect attractants / Repellants
A) CULTURAL CONTROL/METHODS: - Definition: Regular farm operations, so performed as to destroy the insects or prevent them from causing injury. Cultivation practices employed in a manner that makes the environment less suitable for growth & reproduction of the insects.
1) Tillage operations – Ploughing & other tillage operations expose the insects to upper soil surface which are picked by birds or destroyed by heat. e.g. Bihar hairy caterpillar, fruit fly, gram pod borer. It also helps in removal of weeds which may serve as host for insects.
2) Crop rotation – Practice the crop rotation in such a manner which will break the continuous supply of food to the major pests of that crop. Growing of non-host crop reduces the pest attack on crop. Okra followed by cotton increases the pest attack.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 21
3) Trap cropping – The trap crops are those crops which are used to control the pest of main crop. Trap crop plants are harvested early or used as a fodder. Okra is good trap crop for cotton to attract Jassids & spotted bollworms.
4) Sanitation of field – removal & destruction of all undesirable plants, plant debris, weeds & clean cultivation of field. Insects use the plant residues, weeds as a host & increase the pest attack in next season. e.g. sugarcane borer, Jowar stem borer, etc.
5) Time of sowing/planting – By adjusting time of sowing infection of some pests can be prevented. If egg laying period of a pest is avoid; young plants can be establish before the attack starts. e.g. Early sowing of kharif Jowar to escape from attack of Jowar shoot fly.
6) Use of resistant varieties – some morphological or genetic factors associated with the variety make the variety resistant for some pests. e.g. Deshi cotton is more resistant to Jassids whitefly & bollworms than American cotton.
7) Other cultural methods – management of seed rate, pruning, clipping of tips in rice, earthing-up & flooding like cultural practices help to control the pest incidence on the crop. E.g. flooding rice nurseries to eliminate attack of armyworms. Clipping of rice tips at the time of transplanting to eliminate egg masses of stem borer. Merits: - i) It not increase the production cost. ii) Environmentally safe. iii) It is well-matched with other methods of pest control. iv) It gives least chance of insect development. Demerits: - i) Knowledge of ecology & biology is essential. ii) The control measures should be taken well in advance. iii) It should be supplemented with other methods.
B) MECHANICAL CONTROL/METHODS: - Definition: The method with which insect population is directly beat by mechanical devices or manual operations. 1) Hand picking & destruction: - Insects are picked out & destroyed from the crops. This method is applied when the insects are in large number & easily accessible to picker. i) By use of hand nets – e.g. butterflies, moths, grasshoppers, etc. ii) By use of iron hook – e.g. rhinoceros beetles from coconut. iii) Beating with brooms – e.g. locust iv) Shaking of plants – Shaking of babul& neem to collect adult beetles of white grub. v) Sieving and winnowing – used for insects pest of stored grains. E.g. grubs of khapra beetle.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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vi) Rope dragging – Passing of rope across the rice crop to dislodge caseworms over the standing water which then drained out to collect the pests at corner of field. 2) Mechanical exclusion or provision of preventive barriers: - Use of devices by which insects is physically prevented from reaching the crop or the produce. i) Collar around the plants – Paper & tin collars around potato & tobacco to protect from cutworms. ii) Tin bands – fixed over coconut to prevent damage by the rats. iii) Sticky bands – oily bands around mango tree to prevent upward movement of mealy bugs. iv) Trenches around fields – migration of rice armyworms prevented by digging 60×60cm trenches. v) Bagging of fruits – fruit is covered by bags to protect from fruit sucking moth. vi) Use of ant pans – use of four leg rack in vessels containing water to prevent from ants. vii) Screening of houses – screening the windows, doors, etc. to prevent from mosquitoes. viii) Bird scarer – device used to scare away the birds by explosive sounds called bird scarer. 3) Use of Mechanical Devices: -Various traps are used for collecting & killing of insects. i) Light traps – Light is used to attract the insects. e.g. moths, beetles etc. ii) Air suction traps – the traps are fixed in godowns against stored grain pests. iii) Electric trap – live metal screen on which birds & insects are electrocuted. iv) Use of flame thrower – burning of locust adults or hoppers with the help of flame. Merits: - i) Insect population is directly hit by mechanical devices or manual operations. ii) Environmentally safe. iii) Highly special equipments not required. iv) They are economically good & generally popular. v) It is more useful in highly pest populated areas. Demerits: - i) It requires more time to get result i.e. it is time consuming method. ii) These methods are ineffective on large areas & cannot be apply commercially.
C) PHYSICAL CONTROL/METHODS: - Definition: Use of the physical forces or factors of environment for the eradication of insects. 1) Application of Heat – Heating of the empty godowns above 50°c kills the hibernating stored grain pests. Exposing infested grains to the sun in summer also kills stored grain pests. Flame thrower is used to control the locust.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 23
2) Application of cold – refrigeration at 5-10°c of edibles including dry fruits will kill the insect. Many insects fail to multiply below 10°c. Potato is stored at low temperature. 3) Manipulation of moisture – By draining away the stagnant water mosquito’s reproduction stops. Reducing the moisture content of grains below 8% can save from most of the insects. 4) Radio activity – High frequency radio waves generate about 80°c temperature in grains to kill weevils. Male insect can make sterile by gamma radiation. 5) Manipulation of soil – Steam sterilization of soil is done to kill soil insects and nematodes. 6) Sound – Exposure of insects to ultrasonic waves of 100 kilocycles for 4-30 minutes at 500 watts has been found to be lethal to most of insects. Merits: - i) It gives immediate results. ii) These methods are generally popular & believable to farmers. iii) Insects are killed by physical action hence environmentally safe. Demerits: - i) These methods are time consuming & costly. ii) These methods are useful only when much more damage has done. iii) Special equipment are required for heating & refrigeration.
BIOLOGICAL METHOD Definition: Destruction, regulation or suppression of undesirable insects, other animals or plants by introduction, encouragement or artificial increase of their natural enemies. Paul Debach (1973) - The study and utilization of parasitoids, predators and pathogens for the regulation of pest population densities. Predators: Predators are free living organisms that feed on living insects & consume more than one individual during their lifespan. They attack on prey at larval & adult stage. E. g. Lady Bird beetle, Green lace wing, Mantid, Dragon fly, Syrphid fly etc. Parasitoid: An insect parasite of an arthropod that is parasitic in its immature stages killing the host in the process of development and adults are free living. E. g. Trichogramma spp., Apanteles flavips, Epiricania meloneuca, Capidosoma koeheleri, Chilonus blackberni, Braconid wasps etc. Parasites: Parasites are organisms which live on other organisms for getting food & shelter. The association of parasite and host known as parasitism. A parasite weakens or kills the host while feeding requires only one part of one host to reach maturity. E.g. ticks, lice, Bed bugs, Protozoa, Nematodes, Mosquitos etc.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 24
Differentiating points – Sr. Properties True Parasite Parasitoids Predator No. 1 Size Smaller than host Same as that of host Larger than host Only larvae adults are free living Larvae and 2 Feeding stages Larvae and adults (Feed on nectar of flowers ) adults No. of host 3 One one More than one needed Injury to the Feed without 4 Paralyze to oviposit and kill Kill to devour host killing Functions at low Functions at Functions at low host density, so 5 Activity host density, so higher host efficient efficient density 6 Host specificity Great Great Not so great Suitability for 7 biological Not suited Best suited Suited control E. g. Lady Bird ticks, lice, Bed Trichogramma spp., Apanteles beetle, Green bugs, Protozoa, flavips, Epiricania meloneuca, lace wing, 8 Examples Nematodes, Capidosoma koeheleri, Chilonus Mantid, Dragon Mosquitos etc. blackberni, Braconid wasps etc. fly, Syrphid fly etc.
History of biological control
The term biocontrol first time used by H. S. Smith in 1919. He is also referred as father of biocontrol. Paul Debach (1973) - He is a pioneer worker in biocontrol. Ancient times - In China Pharoah’s ant was used to control stored grain pest. Red ant also used to control foliage feeding caterpillar, 1762 - ‘Mynah’ bird imported from India to Mauritius to control locust, 1770 - Bamboo runways between citrus trees for ants to control caterpillar.
November 1888 - First well planned and successful biological control attempt made - In California (USA) Vedalia beetle (Rodolia cardinalis) introduce from Australia to control of cottony cushion scale, pest of citrus, by the scientists Mr. C.V. Riley & Mr. Albert Koeble. This is the first classical example of biological control.
1898 - First introduction of natural enemy into India- 1898 - A coccinellid beetle (Australian lady bird beetle), Cryptolaemus montrouzieri was imported into India from Australia and released against coffee green scale, Cocus viridis. Even today it is effective against mealybugs in South India. 1920 - A parasitoid Aphelinus mali introduced from England into India to control Woolly aphid on Apple, Eriosoma lanigerum. 1929-31 - Rodolia cardinalis (common names vedalia beetle or cardinal ladybird) is a species of ladybird beetle that is sometimes described as endemic to Australia. Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 25
imported into India (from USA) to control cottony cushion scale Icerya purchasi on Wattle trees. Regional Station of Commonwealth Institute of Biological Control (CIBC) established at Bangalore in 1957. Presently Project Directorate of Biological Control (PDBC) Bangalore looks after Biocontrol in India. Recently it called as International Center for Agricultural Important Insects in 2006.
Characteristics of ideal parasites/Qualities of an effective natural enemy Adaptability: It should be Adapted to varied environmental condition & survive in all habitats of pests. Host specific: It should be Monophagous and should be narrow host range. Fast multiplication: Multiply faster than the host Short life cycle with high fecundity and high female: male ratio. High host searching capacity. Easy rearing and mass multiplication/culturing in laboratory. Disperse quickly in locality. It should be free from hyper parasites. It should not harmful to other beneficial species and plant species. It should withstand refrigeration. It should be small and tiny.
Types of parasites - 1) Primary parasites: - The parasites attack on crop pests. 2) Secondary parasites: - The insects which parasitize the primary parasites of pest called secondary parasites. 3) Tertiary parasites: - The parasites attack on secondary parasites. 4) Hyperparasites: - All parasites that are parasite upon other parasites are collectively called as Hyperparasites. 5) Super parasitism: - It is a type of parasitism where more individuals of the same species are present in a single host they can complete their development in normal way. E. g. Larva of pin sawfly carry tachinid fly. 6) Multiple parasitisms: - It is a type of parasitism where the host is attacked by two or more species of parasitoids. E.g. Ecto parasitoid - Feed externally e.g. Bracon brevicornis Endo parasitoid - Feed internally e.g. Chelonus blackburni
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 26
Methods/ Techniques in Biological Control: Three major techniques of biological control 1. Conservation and encouragement of indigenous natural enemies – o It refers to avoid use of those pest control measures that destroy natural enemies. o It can be achieved by use of selective insecticides which do not kill the natural enemies and development of resistant strains of parasite to pesticides. E. g. Endogramma of Trichogramma spp. this is resistant to Endosulfan. o Avoidance of those cultural practices which are harmful for natural enemies. o Preservation of inactive stages of natural enemies. 2. Importation or Introduction – o Natural enemies are introduced from other areas into a new locality (mainly to control introduced pests) o The organization which helpful for finding exotic predator like- 1) Commonwealth Institute of Biocontrol-Trinidad, West Indies 2) International Organization for Biocontrol of noxious animals and plants- Zurich, Switzerland 3) International Center for Agricultural Important Insects- Bangalore, India 3. Augmentation – o It includes activities designed to increase the numbers or effect of existing natural enemies. o Propagation (mass culturing) and release of NE to increase its population. o It may be two types- a. Inoculatve release: This type of release may be made as infrequently as once a year or season to re-establish a species of natural enemies. b. Inundative release: It involves mass culture and release of natural enemies to suppress the pest population directly.
Natural enemies used in Biological control: I] Insects: a) Predaceous insects – Chrysoperla carnia (Green Lace Wing) feed on Aphids, Jassids, whitefly, etc. Cryptolaemus montrouzieri (Australian Ladybird beetle) feed on mealy bugs. Coccinella septumpunctata (Ladybird beetle) feed on aphids Syrphid fly - Feed on different insects. Vedalia beetle feed on cottony cushion scale. Dipha (Conobathra) aphidivora feed on sugarcane wooly aphids. b) Parasitic insects - (Parasitoids) Egg Parasitoids - Trichogramma japonicum: parasite of stem borer of paddy. Trichogramma chilonus - parasite of Cotton bollworms & sugarcane stem bores. Larval Parasitoid - Bracon kirkpatrickii & Apanteles angaleti parasite of cotton bollworms.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 27
Egg-Larval Paranoids - Capidosoma koeheleri & Chilonus blackberni - parasite of potato tuber moth. Nymphal & Adult Parasitoid - Epiricania meloneuca - parasite of sugarcane pyrilla. Aphelinus mali - parasite of Apple wooly aphids. II] Predatory vertebrates: Birds – Useful birds which destroyed crop pests includes king-crow & myna. Ducks used in rice to control bug. Fishes – Destroy large number of mosquito larva. Frog – Destroy paddy stem borer. Toad & wall lizard – Live on insects such as termites‟ crickets, grasshoppers, bug, etc. Snakes –feed on rats. III] Nematode parasites: 46 nematodes species, parasitizing various species of beetle, grasshoppers, cockroaches, moths etc. Neoaplectana glaseri used for control of Japnese beetle. Nematodes especially rhabditids are found to have a symbiotic relationship with the bacteria, forming disease complex. E.g. DD-136 Association beetween the nematode Neoplanctana caprocapsi and bacterium Acromobacter nimatophilus against Codling moth of apple. IV] Pathogens: . Certain microorganism able to causing diseases in insects which includes fungi, bacteria, viruses, protozoa, rickettsia and nematodes. . Microbial control: - It is a branch of biological control which deals with study and utilization of microorganism for the suppression of pest population density. . The Microbial control first time used by the E. A. Steinhause in 1949 referred as a ‘Father of Insect Pathology’ worked on Muscardine diseases of silkworm. 1) Fungi – The fungi which cause disease in insects called as Entomopathogenic fungi. Adults are more affected than larvae to Entomopathogenic fungi. Fungi require high atmospheric humidity to germinate. Fungi get entry through integument, via respiration. Fungus gets entry with the help of aspersoria which is present on conidia. They are usually attack on dipteran insects followed by Hemiptera, lepidopteran & coleopteran. Besides Entomopathogenic fungi the other fungi is also attack on insects like Entomophilic fungi (insect loving) and Entomophagous fungi (feed on insects) E.g. Green muscardine fungus- Metarhizium anisopliae attack on coconut rhinoceros beetle & sugarcane pyrilla, White muscardine fungus- Beaveria bassiana against lepidopteran larvae, White halo fungus- Verticillium lecanii on coffee green scale & Entomophthora grylli on grasshoppers.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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2) Bacteria –The bacteria cause disease in the insects when they infect through ingestion. a) Spore forming (Facultative, Crystelliferous) - They produce spores and also toxin (endotoxin). The endotoxin paralyses gut when ingested by insects e.g. Bacillus thuringiensis var. kurstaki effective against lepidopteran & it is stomach poison. Commercial products - Delfin, Dipel, Thuricide b) Spore-forming (Obligate) - e.g. Bacillus popilliae attacking on beetles cause ‘milky disease’. Commercial product - ‘Doom’ against ‘white grubs’ c) Non-spore forming - e.g. Serratia entomophila on grubs 3) Viruses – There are six families of insect viruses. Among them baculoviridae is important which includes the nuclear polyhedrosis & granulosis are most lethal & promising viral insecticides which cause disease in Lepidoptera larvae. Insect viruses have great potential for field because of their specificity & effectiveness against important crop pests. Two types of viruses are common. a) NPV (Nucleo polyhedrosis viruses) - e.g. HaNPV (Helicoverpa armigera nuclear polyhedrosis viruses) against American bollworm, SlNPV (Spodoptera litura nuclear polyhedrosis viruses) against tobacco leaf eating caterpillar. b) GV (Granulovirus viruses) - e.g. CiGV (Chillo infuscatellus Granulovirus viruses) 4) Protozoa – The role of protozoa as microbial agents in artificial control is limited because of difficulties in their mass multiplication for field release. E.g. Nosema bombycis on silkworm and Perezia pyraustae on Eropian corn borer. 5) Biological control of weeds Lantana camara (Ghanery) control by Lantana seed fly Agromyza lantinae. Maxican beetle, Zygogramma bicolorata effective against parthenium. Leaf eating weevils, Neochetina spp. feed on water hyacinth. Advantages of biological control: - i) Complete control over large area is possible. ii) Co-operative efforts of farmers of a locality are not necessary. iii) It is cheap method as it useful to long time. iv) Biological agents will survive as long as the pest is survive. v) It is environmentally safe. vi) There is no pest resistance problem. Demerits biological control: - i) It is slow process & takes long time. ii) Not suitable where immediate control required. iii) Effectiveness depends upon climate. iv) Multiplication on large scale is difficult i.e. storage not possible. v) The work cannot be restricted at a particular area. vi) If alternate hosts are present it may not give desired effect. vii) Work of biological agents may affect due to the Hyperparasites.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 29
LEGAL METHODS Definition: It is defined as way of controlling pests by imposing various legal restrictions in order to prevent the entry of foreign pest or to prevent the spread of pests within country. Pests Accidentally Introduced into India (Exotic pests) 1. Pink bollworm - Pectinophora gossypiella 2. Cotton cushion scale - Icerya purchasi 3. Wooly aphid of apple - Aphelinus mali 4. San Jose scale - Quadraspidiotus perniciosus 5. Potato tuber moth - Gnorimoschima operculella 6. Cyst (Golden) nematode of potato - Globodera sp. 7. Giant african snail - Acatina fullica 8. Subabul psyllid - Heteropsylla cubana 9. Spinalling whitefly - Aleyrodicus dispersus Foreign Pests from Which India is Free- 1. Mediterranean fruit fly, 2. Cotton boll weevil & 3. Codling moth of apple. Quarantine - Isolation to prevent spreading of infection. Plant Quarantine - Legal restriction of movement of plant materials between countries and between states within the country to prevent or limit introduction and spread of pests and diseases in areas where they do not exist. Pest Legislations 1905 - ‘Federal Insect Pest Act’ - first Quarantine act against San Jose scale in USA. 1912 - ‘US Plant Quarantine Act’ 1914 - ‘Destructive Insects and Pests Act’ of India (DIPA) 1919 - ‘Madras Agricultural Pests and Diseases Act’ 1968 - ‘The Insecticides Act’ Different legislative measures: i) Legislation to prevent the introduction of new pest, diseases & weeds from foreign countries. ii) Legislation to prevent the spread of already established pest, diseases & weeds from one part of country to another. iii) Legislation to enforce upon the farmers for application of effective control measures to prevent the damage by already established pest, diseases & weeds. iv) Legislation to prevent the adulteration & misbranding of insecticides & to determine the permissible residue tolerances in food stuffs. v) Legislation to regulate the activities of pest control operations & the application of hazardous insecticide.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 30
Categories of legal Methods/Different Classes of Quarantine: 1) Foreign quarantine: Legislation to prevent the introduction of new pest, diseases & weeds from foreign countries. To prevent the entry of foreign pests, in the world have restrictions on the import of infested or infected plant materials under the provisions of quarantine laws. These plants materials examined at each seaports like Mumbai, Calcutta, Cochin & Chennai and airport like Amritsar, Mumbai, Calcutta, and Chennai & New Delhi. These stations operate under the provision made under the Government of India’s Destructive Insects and Pests Act of 1914. The “Phytosanitary Certificate” should be issued by the officer of Department of Agriculture of exporting country as to their freedom from pest & diseases. The Central Directorate of Plant Protection and Quarantine was established in 1946. 2) Domestic quarantine: Legislation to prevent the spread of already established pest, diseases & weeds from one part of country to another. “The Bombay Agricultural Pests and Diseases Act” was passed in 1947 and accordance with this the domestic quarantine in the state is being implemented. The Directorate of Plant Protection, Quarantine and storage is overall Incharge for this work and it operates through several Inter-State check posts. So far Cottony cushion scale and San Jose scale were covered under this type of quarantine. 3) Pest Act: Legislation to enforce upon the farmers for application of effective control measures to prevent the damage by already established pest, diseases & weeds. Under the provision of “The Bombay Agricultural Pests and Diseases Act” State Government may declared that certain pest is injurious in given area & carry out preventive and remedial measures in order to eradicate the pest within a specified period. 4) Insecticides Act: Legislation to prevent the adulteration & misbranding of insecticides & to determine the permissible residue tolerances in food stuffs. The manufacture of insecticides should resister themselves stating the name and address of the manufacturer, the brand and trade name of the insecticide, active ingredient and other constituents of the product to be manufactured, its net contents in an unit pack which should also carry in detailed directions for use including the antidote against the insecticide in case of poisoning. The container should carry “poison label” with warning or caution statement.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 31
The Government of India passed the Insecticide Act, 1968 (No. 46 of 1968) on 2nd September, 1968 to regulate the import, manufacture, sale, transport, distribution and use of insecticides with a view to prevent risk to human beings and animals. The Insecticides Rules framed under the Insecticide Act, 1968 (46 of 1968) came in to force in 1st Jan, 1971. Licensing authority - In Maharashtra the commissioner of Agriculture, M.S. Pune is the Licensing authority. However on behalf of him, Chief Plant Protection Officer, MH State, Pune act as licensing officer for manufacture and formulation of pesticides and for sale and stock concerned Divisional Superintending Agriculture Officer acts as licensing officer. Appellate Authority - any appeal against any decision of the licensing officer is made to Appellate Authority. In MH, Joint Director of Agriculture (Extension), Department of Agriculture M. S. Pune acts as Appellate Authority. Insecticides Inspectors (Quality Control Officers) - The District Agriculture Officer of Z.P. & Sub-divisional Agricultural Officers of Department of Agriculture can collect the insecticides samples from the shops to ascertain their purity through insecticidal residue laboratories. Objectives: 1. To prevent the adulteration & misbranding of insecticides. 2. To regulate the import, manufacture, sale, transport, distribution and use of insecticide. 3. To help and guide farmers for the use of insecticides.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 32
CHEMICAL CONTROL Chemical Control: Management of insect pests using chemical pesticides is termed as chemical control. Or Pest control with the help of various chemicals is called as chemical control. Pesticides: - The chemicals which applied for control of insect pests are called as pesticides. History of insecticides development Year Chemicals Discovered 900 Arsenites used in China (Inorganic compound) 1690 Tobacco extract used in Europe (Plant/natural product) 1787 Soaps used in Europe 1858 Pyrethrum was first time used for insect control in USA 1867 Paris Green in US 1874 DDT synthezized by Zeidler 1883 Bordeaux Mixture used in France 1892 Lead arsenate was used for control of Gypsy moth in USA 1925 Dinitro compounds used (First synthetic organic insecticide) 1939 Discovered of insecticidal property of DDT by Paul Muller in Switzerland. (Awarded Nobel Prize in 1948) 1941 BHC used or discovered the insecticidal property in France and UK (in 1942) (BHC is presently called as HCH) 1944 Parathion (Organophosphate) discovered by Gerhard Schrader in Germany 1945 Chlordane (Cyclodian compound) used in Germany 1947 Carbamate insecticides in Switzerland 1962 Miss Rachel Carson’s wrote the book name ‘Silent Spring’ in US which gives the impact of insecticides on environment. 1967 First JH mimic (Juvenile Hormone mimic) used in US (Insect growth regulator) 1970 Development of synthetic pyrethroids (UK) (Fast degradation) (Effective at very low doses) 1980 Discovery of avermectins (derived from bacteria). Effective at low dose. Fast degradation. 1990 Discovery of newer groups like (1) Neonicotinoids (Imidacloprid), similar to natural nicotine, (2) Spinosyns (e.g. Spinosad) derived from actinomycet
Various generations of insecticides Generation Year Compounds 1. First generation insecticide 1939-1942 BHC and DDT 2. Second generation insecticide 1944-1947 Organophosphates and Carbamate 3. Third generation insecticide 1967 Hormonal insecticides, JH mimic insect growth regulators 4. Fourth generation insecticide 1970s Synthetic pyrethroids Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 33
Classification of Pesticides/Pesticides Groups The pesticides are generally classified into various groups based on pest organism against which the compounds are used, their chemical nature, mode of entry and mode of action. 1. Based on organism against which the compounds are used Sr. Name of insecticides Definition No. 1 Insecticides Chemicals used to kill or control insects. E.g. Carbaryl, malathion 2 Rodenticides Chemicals used to kill the rodents called rodenticides. E.g. Zinc phosphide 3 Acaricides/Miticides Chemicals used to kill the mites, ticks and spider called acaricides. E. g. Dicofol, Properguite 4 Avicides Chemicals used to repel the birds. E.g. Anthraquionone
5 Molluscicides Chemicals used to kill the snails and slugs. E.g. Metaldehyde 6 Nematicides Chemicals used to control nematodes E.g. Ethylene dibromide 7 Fungicides Chemicals used to control plant diseases caused by fungi. E.g. Copper oxychloride 8 Bactericide Chemicals used to control plant diseases caused by bacteria. E.g. Streptomycin sulphate
9 Herbicide Chemicals used to control weeds. E.g. 2,4,D 10 Algicides Chemicals used to control algae. 11 Arboricides Chemicals used to control trees or shrubs. 12 Piscicides Chemicals used to control harmful fishes.
2. Classification based on Mode of entry a) Stomach poison – Insecticides applied on leaves and other parts of plants when ingested get entry in insects & act on digestive system to cause death of the insect. This type of chemicals is limited mainly to the chewing type of insects like grasshopper, beetles, caterpillar etc. The stomach poison should be sufficiently stable, cheap, and palatable for the pest, available in large quantities. These chemicals may be applied in the form of dust or spray or in poison bait. E.g. Bt, Organochlorine and organophosphates insecticides etc. b) Contact poison – The toxicant which causes death of insect by means of contact with insecticide. Insecticides get absorb by the sutures, membrane & tracheal system on insect body. This is achieved by direct application of insecticides on pest species. E.g. Nicotine, Pyrethrum, quinolphos, Malathion, synthetic pyrethroids etc. Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 34
c) Fumigants – Toxicant which in its gaseous state or in vapour form penetrate in insect through the tracheal system (respiratory poison) through spiracles & kills the insect. Their application is limited to plants or plant products in air-tight enclosures. E.g. Methyl Bromide, Hydrogen cyanide (HCN), ethylene dibromide, DDVP, Lindane. d) Systemic poison - Chemicals when applied to plant or soil are absorbed by foliage (or) roots and translocated through vascular system and cause death of insect feeding on plant. It is effective against the pest having sucking type of mouth parts such as aphid, jassid, thrips, white fly etc. E.g. Dimethoate, Imadaclopirid, Phorate, carbofuran etc.
3. Classification based on mode of action: - a) Physical poison – Chemical which can kill insects by following three ways; Asphyxiation – A physical poison kill the insects exert by physical effect through asphyxiation i.e. exclusion of air called physical poison. E.g. effect of heavy oil & Tar oil on scale insects. Moisture stress – Loss of moisture from insect body by inert dust, charcoal, activated clay, ash etc. Mechanical injury – Epicuticle of insect gets lacerated by abrasive dust like aluminum oxide & this may cause water loss. b) Protoplasmic poison – Toxicant responsible for precipitation of protein, destruction of midgut epithelium called as protoplasmic poison. E.g. Heavy metals like mercury, copper, Fluorine. c) Respiratory poison – The chemical which block cellular respiration, inactivation of respiration & respiratory enzymes. This is known as anoxia. E.g. Hydrogen cyanide (HCN), Carbon monoxide (CO). d) Nerve poison – The chemicals which affect the nervous system of the insect or Chemicals inhibit the production of acetylcholinesterase enzyme in insects called as nerve poison. E.g. organophosphate, carbamate, organochlorines, pyrethrum and nicotine. e) Chitin inhibition - Chemicals inhibit chitin synthesis. E.g. Diflubenzuron
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 35
1. Classification based on the Chemical nature of insecticide
Inorganic compounds Organic compounds
1. Arenicals 2. Fluorine Hydrocarbon Animal origin Plant origin Synthetic organic compounds oils (Nereis toxin) 1. Nicotine compounds 3. Sulphur Petrol, Kerosin alkaloids Organoclorines 4.Lime & oil, Coal tar oil 2. Pyrethroids Organophosphates sulphur etc. 3. Rotenoids Carbamates 5. Barium 4. Neem extract Synthetic carbonate pyrethroids 6. Zinc phosphoid
A) Inorganic Compounds: - The insecticides derived from naturally occurring elements which do not contain carbon. It comprises compounds of mineral origin and element Sulphur and phosphorus. They are stable, non-volatile and soluble in water. Many of them are persistent and because of their residual persistent high mammalian toxicity it’s a limited used. Both boric acid and silica used in baits for controlling the household pests like cockroaches and ants. 1) Arsenicals - These are stomach poisons formed of toxic compounds of non-toxic elements arsenic. They are phytotoxic & not applied on plants. It is used in poison baits. They kill the insects due to the inhibition of respiratory enzyme. They are more stable and not harmful to plants. E.g. lead arsenate, Calcium arsenate, Sodium arsenate, etc. 2) Fluorine compounds - They kill the insects more rapidly than arsenicals. They are cheaper & less toxic to higher animals. They are stomach & contact poison. They are irritating to the appendages of insects. These are cheaper and non-toxic to plants and animals. E.g. Sodium fluoride, Sodium fluosilicate.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 36
3) Sulphur - It is a contact poison. It is available in the form of both formulation dust as well as Wettable powder. It is used as acaricide as well as fungicide. 4) Lime Sulphur - It is prepared by boiling lime & Sulphur together in water (1:2). It is used against aphids, mites, San Jose Scale etc. 5) Zinc-phosphide - It is rodenticide used to control rat. It is heavy dark grey powder with disagreeable odour. Baits containing 2 % zinc phosphide are recommended for control of rats. In rats the chemicals reacts with the hydrochloric acids present in the stomach and release phosphine gas which is lethal to the rats. 6) Barium carbonate-
It is also acts rodenticide. After ingestion internal bleeding of intestinal tract & kidneys occurred.
B] Organic Compounds: - These are man-made or extracted pesticides consisting of carbon, hydrogen and chlorine, oxygen, sulphur, phosphorus and nitrogen. a) Hydrocarbon oils: Oils composed of hydrogen & carbon. It has two groups viz. 1) Mineral oils – These are petroleum oils derived from secondary rocks. E.g. Kerosene, Petrol, Lubricants oil etc. 2) Coal-tar oils – These are creosol oil & green oils are useful for insecticidal purpose. E.g. summer oils, dormant oils, spray oils, supreme spray oils and Borer solution to control bark borer, stem borer. b) Animal origin insecticides: A toxin isolated from Marine annelids, Lumbrineris heteropoda & Lumbrineris vicirra. i.e. Nereis toxin. Insecticidal properties of Nereis toxin has been found by Nitta in 1934 and it is given by Sakai in 1964. Common name of Nereis toxin is Cartap and Trade name is Padan. It is effective against rice stem borer & cabbage diamond moth.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 37 c) Plant origin insecticides: (Botanicals insecticides/Natural insectcides) Toxicants derived from plants & used in insect control. It includes nicotine, pyrethrum, rotenone, Azadirachtin, Scilliroside, Pongram, Rynia, Sabadilla. Certain plant products also used as a nematicides, insect attractants and repellants and as diluents in insecticidal formulation. 1) Nicotine - Tobacco was used in insect control as early as 1763, the principal alkaloid Nicotine was discovered in 1828. The chief source is Nicotiana tabaccum & Nicotiana rustica. 12 alkaloids have been isolated from tobacco and alkaloid Nicotine constitutes 97% of the total alkaloids. Nicotine in leaves of N. tabacum is 2-5%. Nicotine is obtained from leaves and stem of waste tobacco by steam sterilization. It is nerve poison & highly toxic when absorbed through cuticle/trachea. The commercial product is Nicotine sulphate containing 40% alkaloid. It is water soluble. It may be used as a spray or dust. It is effective against soft bodies insects like thrips, hoppers, etc. It is also a neuro-muscular poison in man and animal hence its used is discouraged. 2) Neem - The neem tree i.e. Azadirachta indica which is indigenous to India having the various medicinal and insecticidal values. Now days it is assuming as an International Tree. All parts of neem possess insecticidal activity but seeds are main source which is most effective. Neem bark leaves and neem oil as well as extracts with various solvents like ethanol are found effective. Azadirachtin is the main active ingredient present in neem with other alkaloids like limonoids and protolimonoids which shown repellent, antifeedants and insecticidal activity. The antifeedants activity against desert locust which is shown by Pradhan et al. in 1962. It is used as growth inhibitor, cause egg sterility & adverse effect on fecundity. It is effective against American bollworm, leaf eating caterpillar, Diamond back moth, and armyworm and sucking pest like leaf hoppers, thrips. Many commercial formulations are available in market like Achook, Bioneem, Econeem, Neemark, Neemazal, Neem oil. 5% Neem Seed Kernel Extract (NSKE) is mostly used in IPM programmes. 3) Pyrethroids/Pyrethrums/Pyrethrins - These are extracted from Chrysanthemum flower which contain active ingredients pyrethrin I and II & cinerin I and II. Pyrethrums are dried flower powder of Chrysanthemum, Pyrethrins are all the active toxins of pyrethrum and Pyrethroids are synthetic derivatives of pyrethrin. All pyrethroids are lipophilic (Fat loving) compounds and insoluble in water.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 38
It show higher toxicity against insects & very safe to mammals. These are contact poisons. Synthetic Pyrethroids like Cypermethrine, Permethrin, Deltamethrin, Decamethrine and fenvalerate are effective against soft bodies & lipidopterous insects which are contact and stomach poisons. Allethrin was the first synthetic analogue of pyrethrum developed in 1949. 4) Rotenone - It is derived from roots of bean legumes, Derris eliptica. Used in 1848 against leaf eating caterpillar. The active ingredient i.e. rotenone is isolated by the scientist Geoffroy I 1882. It is a contact and stomach poison. It inhibits respiratory metabolism‟. It is extremely toxic to fish hence used as a piscide (The chemical which is used to kill the fishes). 5) Scilliroside - These are obtained from the bulb of Red Squill, Urginea maritime. The active ingredient presents i.e. Scilliroside which is generally used as rodenticides. It is a stomach poison. It is used to control the rats and mice. 6) Pongramm - These are derived from the plant Pongamia pinnata (Karanj). The active ingredient presents i.e. Pongram has been identified as ‘karanjin’. Karanj oil applied as surface protectant and repellent. It is used against pulse beetle and sucking pests. 7) Sabadilla - It is an alkaloid extracted from seeds of Schoenocaulon officinale. 8) Rynia - It is extracted from stem, roots, leaves and stalks of tropical shrub of Ryania speciosa. Salicaceae, South American plant. It is water soluble powder. Extract contains several structurally related ryanoids including –ryanodine and 9, 21- dehydroryanodine. The extract has a very low acute toxicity to mammals. Used for control of both adults and larval Lepidoptera.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 39 d) Synthetic organic insecticides: - These are dominating the field of pest control today. Historically Denitrophenols come first in 1925. It includes organochlorine, organophosphate, carbamates and synthetic pyrethroids. 1) Dinitrophenols: ((DNOC) They are Stomach poison with ovicidal effect on eggs of certain insects. E.g. Dinocap 2) Organic Thyocinates: It cause quick knock down effect. It is contact poison. E.g. Loro - Used against thrips, mites and aphids. Thanite - Used against housefly and cattle pests. 3) Chlorinated hydrocarbons or organochlorines compounds: It includes DDT, BHC and Cyclodiene compound. DDT- (Dichlorodiphenyl trichloroethane) It was synthesized by a German chemist Zeidlar in 1874. Its insecticidal properties were given by Paul Muller in 1939. The proper chemical name of DDT is 2, 2-bis (P-chlorophenyl) 1, 1, 1- (trichloroethane). It was very effective against flies, mosquitoes, lice and fleas and also used in agriculture and horticulture sector. It has long residual life and persistence in the soil in aquatic environment and also accumulates in plant and animal tissue hence it’s used is banned in agriculture. DDT analogues - DDD (Dichloro diphenyl dichloroethane), Dicofol (Kelthane-It is an acaricides), Methoxychlor. BHC- (HCH) The proper chemical name of HCH is 1, 2, 3, 4, 5, 6- Hexachloro cyclohexane and common name is benzene hexachloride. It is synthesized by a Michael Faraday in 1825. Its insecticidal properties were given by A.P.W. Dupire in 1941 and F.D. Leicester in 1942. BHC is a mixture five isomers in which gamma isomers were found to have insecticidal properties is known as HCH. A product containing 99% pure gamma isomers called lindane name proposed after Vander Lindane, who was isolate this isomers in 1912. HCH is stomach and contact poison and has fumigant action. Lindane mostly used in control of stored grain pests. Cyclodiene compound - Due to the persistence in the soil, resistance in insect, fish toxicity and serious environmental hazards is being banned insectcides.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 40
It includes Endosulfan, Aldrin, Dieldrin, Heptachlor and chlordane. Endosulfan - Its insecticidal properties were first discovered by W. Finkenbrink in1956. It is a stomach and contact poison. It is effective against sucking pests, caterpillars and borers. It is available in the form of dust, EC and granule formulations. Chlorinated terpenes - e. g. Toxaphene 4) Organophosphorus insecticides or organophosphates: They comprise a large group of compounds. They are generally acutely toxic to man and animals and they are non-persistent. They have a short residual activity. They are nerve poison which inhibits the cholinesterase enzyme. These are stomach, contact and systemic in activity. It has been used in large scale for agriculture because of its high efficacy against many insects-pests, low mammalian toxicity, short residual activity and little resistance among insect-pests. Insecticides like Dematon, Dimethoate, Phorate, Phosphamidon and Monocrotophos have asystemic action hence it is used against sucking pests. Dichlorvos or 2, 2-dichlorovinyl dimethyl phosphate (commonly abbreviated as DDVP) and Tetraethyl pyrophosphate, (abbreviated TEPP) is an organophosphate, widely used as an insecticide to control household pests, in public health, and protecting stored product from insects. Monocrotophos shows the some acaricidal activity and Dichlorvos shows the fumigant action. Examples - Monocrotophos, Dichlorovos, Triazophos Chloropyriphos, Profenophos, quinophos, Malathion, Phosphamidon, Fenthion, Methyl parathion, Trichlorofon, Methyl dematon, Ethion, Formothion, Fenitrothion, Dematon, Dimethoate, Acephate, Phorate, Fipronil, Indoxacarb, etc. 5) Carbamates: These are ester of carbamic acids. They generally have a short residual activity and a very broad-spectrum effectivity as insecticides, miticides, nematicides and molluscicides, Carbary - The trade name of carbaryl is Sevin. It is contact and stomach poison. It is available in the form of dust, granules and Wettable powder formulation. It is very popular in horticulture for pest management. Carbofuran - The trade name is Furadan. It is systemic in action hence effective against sucking pests. It is also used as nematicides and soil pests. Other examples of carbamates such as Aldicarb, Mythomyl, Thiodicarb, Oxamyl etc. Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 41
6) Synthetic pyrethroids - These are extracted from Chrysanthemum flowers. These are the mixtures of six esters named pyrethrin I and II, cinerin I and II and jasmolin I and II. Generally it is botanical insecticides but as they contain only one of these esters, isect species tend to develop resistance to them. Generally pyrethroids shows low mammalian toxicity but pyrethrum, are highly toxic to fish and bees because they having all six esters properties hence it is not suited in agriculture. These are contact and stomach poisons. Examples - Allethrin, Resmethrin, Deltamethrin, Permethrin, Fenvalerate, Cypermethrin, Cyfluthrin and Bifenthrin.
7) Fumigant: These are the substance which produces gas, vapour, fumes or smoke intended to kill insects, nematodes, bacteria or rodents. Generally these are solid, liquid or gaseous substances which contain halogen atoms. They are used to disinfect the buildings, stored produce or the soil. Chloropicrin is called as “tear gas”. E.g. Chloropicrin, Aluminium phosphide tablets, Ethylene dibromide, Methyl bromide, Formaldehyde, Phosphine, Naphthalene.
New groups of insecticides/ Newer Insecticides
A) Neonicotinoids - These are new class of insecticides with novel mode of action. It is effective against sucking pests. It acts on the nicotine acetylcholine receptors (nAChR) at the synaptic junctions of insect central nervous system. Examples - Imidacloprid, Acetamiprid, Thiomethoxam, Thiocloprid, Clothianidin etc. Imidacloprid - The trade name is Confidor (Bayer), Gaucha (Bayer), Admire etc. It is effective as a seed dressing Gaucha (Bayer) and foliar application Confidor (Bayer) against sucking pests like Aphid, Jassids, Thrips and White fly. Acetamiprid - The trade name is Pride, Dhanprit, Manik, Lift, Polar, mudra, Record, Enova. It is broad spectrum insecticides effective against sucking pests. Thiomethoxam - The trade name is Cruiser (Syngenta), Actara (Syngenta). It is broad spectrum insecticides effective against sucking pests as a seed treatment Cruiser (Syngenta) and foliar spray Actara (Syngenta).
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 42
Thiocloprid - The trade name is Alanto, Calypso. It is broad spectrum insecticides effective against the insect pests. It acts as a stomach poison. B) Spinosyns - Spinosad - It is introduced by Dow-Elango in 1994. It is derived from new species of Actinomycetes, Saccharopolyspora spinose. It is commercially available as Spinosad (Tracer). It acts as stomach and contact poison. Spinosad is a mixture of spinosyns A and D. It is broad spectrum insecticides effective against caterpillars. It acts on the nicotine acetylcholine receptors (nAChR) at the synaptic junctions of insect central nervous system. C) Avermectins - These are generally best for the control of greenhouse pests and insects like leaf miners, spider and mites. It possess novel mode of action by acting on GABA (Gamma Amino Butyric Acid) regulated chloride channels of central nervous system in insects. They are derived from Streptomyces avermitilis by Merck & Co. Abamectin - The trade name is Vertimec. It is a mixture of two analogs i.e. 80% Avermectins B1a and 20% B1b. It acts as a systemic action. Emamectin Benzoate - The trade name is Proclaim, Derim, Safari, Tatkal . It is analog of abamectin. It is effective against caterpillars. It acts as a both stomach and contact poison. C) Oxadiazines - Indoxacarb - Commercially available as an Avaunt. It is sodium channel blockers in nervous system. They have a novel mode of action and it is effective against those pests which developed resistance against synthetic pyrethroids. D) Phenypyrazoles - Fipronil - Commercially available as an Icon and Regent. It is effective against those pests that are already become resistance to pyrethroids, organophosphates and carbamates. It possess novel mode of action by acting on GABA regulated chloride channels of central nervous system in insects. It is stomach and contact poison with systemic action. It can use as a foliar, seed treatment and soil application for controlling pests. Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 43
E) Diamides - These are the Ryanodine receptors modulators. A large Ca++ release channel in the membrane of muscle sarcoplasmic reticulum (SR) is called the ryanodine receptor, because of sensitivity to inhibition by a plant alkaloid ryanodine. Ryanodine - It is neutral alkaloid isolated from the stem, roots, leaves and stalks of plant Ryania speciosa. It is contact as well as stomach poison. Flubendiamide - First synthetic ryanodine receptor insecticide to be commercialized. Commercially available as Fame (Bayer) in Suspension Concentrate (SC) formulation and Takumi (TATA) in Granule formulation. It is effective against lepidopteran pests. It is safe to bees and other natural enemies.
Rynaxypyr (Chlorantraniliprole) - Commercially available as Coragen (Dupont). It is effective against lepidopteran pests. It is available in Suspension Concentrate (SC) formulation. Rynaxypyr controls insect pest by activating insect ryanodine receptors. Cyazypyr (Cyantraniliprole) - Commercially available as Benevia (Dupont). It is available in Oil Dispersion (OD) formulation. It is effective against lepidopteran pests and also sucking pests. It also shows ovicidal and larvicidal effect. It also harmful to bees and other natural enemies.
F) Cartap Hydrochloride -
It is Nereistoxin analog means animal originated insecticides. It is extracted form a marine annelids, Lumbriconereis heteropoda. It is contact, stomach and systemic poison. It is effective against chewing and sucking pests. Commercially available as Caldan, Padan, Campas. It is available in the formulation of Soluble Powder (SP).
G) New Pyrethroids -
Examples - Lambda-cyhalothrin (Karate, Matdor, Riva), Bifenthrin. The mode of action is same as that of synthetic pyrethroids. They have broad spectrum activity against white fly, mites and cotton bollworm. Lambda-cyhalothrin is also used for control of mosquitoes and thrips.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 44
H) New Acaricides / miticides -
Fenazaquin - Commercially available as a Magister. It is contact poison. It is a Mitochondrial Electron Transport Inhibitor. It is environmentally safe. Propergit - Commercially available as an Omite, Proguard, Indomite. It is stomach poison and fumigants action. Spiromesifen - Commercially available as an Oberon. It is lipid biosynthesis inhibitor. It is available in Suspension Concentrate (SC).
I) Insect Growth Regulators (IGR’s)
Insect Growth Regulators (IGRs) are compounds which interfere with the growth, development and metamorphosis of insects. It acts on the endocrine system of insects. It is environmentally safe. IGRs include synthetic analogues of insect hormones such as ecdysoids and juvenoids (JH Mimics), non-hormonal compounds such as Anti JH and chitin synthesis inhibitors. Juvenile Hormones Mimics (JH Mimics)- JH mimics were first identified by Williams and Slama in the year 1966. JH Mimics have anti-metamorphic effect on immature stages of insect. JH Mimics are larvicidal and ovicidal in action and they disrupt diapause and inhibit embryogenesis in insects. Methoprene, Fenoxycarb, Novaluron Pyriproxyfen are used as Juvenile Hormones Mimics. Fenoxycarb has been used for fire ant management. It sterilized the queen of colony. Pyriproxyfen used for suppressing the pests like flies, mosquitoes. Chitin synthesis inhibitors - Benzoyl phenyl urease has been found to have the ability of inhibiting chitin synthesis in vivo by blocking the activity of the enzyme chitin synthetase. It prevents the acetylation of glucose to form glucosamine which is one of the components of the insect exoskeleton. E.g. Lufenuron and Flufenoxuron. Two important compounds in this category are Diflubenzuron (Dimilin) and Penfluron. Another compound from the class is thiadizines, buprofezin has been effective against hemipteran insects like white fly. It inhibits the biosynthesis of chitin.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 45
Recent /Newer Methods of Pest Control
1) Attractant 2) Repellents 3) Antifeedants/Feeding deterrents 4) Sterility technique 5) Hormones 6) Gamma radiation 7) Genetic control (Transgenic crops)
1) Insect Attractant Chemicals that cause insects to make oriented movements towards their source are called insect attractants. They influence both gustatory (taste) and olfactory (smell) receptors. The interspecific semiochemicals that favor the producer are called Allomones. While those favors the receiver called as Kairomones. Types of Attractants: a) Pheromones: Pheromones are chemicals secreted into the external environment by an animal which elicit a specific reaction in a receiving individual of the same species. i) Sex pheromones – A sex pheromones released by one sex only to attract the other sex of the species. E.g. For cotton bollworm- Vitlure & Ervitlure for spotted bollworm, Helilure & Hexalure for American bollworm. ii) iii) Aggregation pheromones – The pheromones released by one sex only give response in both sexes of a species. E.g. Melon fruit fly attracted by cue-lure. b) Food lures: Chemical present in plants that attract insect for feeding. They stimulate olfactory receptors.
List of natural and synthetic food lures Insect-Pests Natural and synthetic food lures Natural Pests of cruciferous Iso-thiocyanates from seeds of cruciferous Onion fly Propylmercaptan from onions Bark beetle Terpenes from barks Housefly /Moths/Butterflies fermenting syrup, Sugar and molasses Synthetic Oriental fruit fly Methyl eugenol Mediterranean fruit fly Cuelure Melon fruit fly Trimedlure DBM (Diamond Back Moth) Sinigirin
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 46
c) Ovipositional lures: - Chemicals that govern the selection of suitable sites for oviposition by adult female. E.g. paramethyl-acetophenon = Rice stem borer, Helicoverpa lay eggs more on plants which dipped in juice of corn silk. 2) Repellents Chemicals that induce avoiding (oriented) movements in insects away from their source are called repellents. They prevent insect damage to plants or animals by rendering them unattractive, unpalatable or offensive. Types of repellents I) Physical repellents: Produce repellence by physical means Contact stimuli repellents: Substances like wax or oil when applied on leaf surface changes physical texture of leaf which are disagreeable to insects Auditory repellents: Amplified sound is helpful in repelling mosquitoes. Barrier repellents: Tar bands on trees and mosquito nets are examples. Visual repellents: Yellow light acts as visual repellents to some insects. Feeding repellents: Antifeedants are feeding repellents. They inhibit feeding. II) Chemical repellents: Repellents of Plant origin: Essentials oils of Citronella, Camphor and cedar wood act as repellents. Commercial mosquito repellent ‘Odomos’ uses citronella oil extracted from lemongrass, Andrpogon pardus as repellent. Pyrethrum extracted form Chrysanthemum is a good repellent. Creosol and coal-tar oil protect wood form termite attacks. Synthetic repellents: Repellents synthetically produced. Insects Repellents Mosquito, blood suckers Dimethyl phthalate Mites (chiggers) Benzyl benzoate Crawling insects Trichloro benzene Phytophagous insects Bordeaux mixture Wood feeders Pentachlorophenol Fabric eaters Naphthalene or mothballs Bees Smoke
3) Antifeedants/Feeding deterrents Antifeedants are chemicals that inhibit feeding in insects when applied on the foliage (food) without impairing their appetite and gustatory receptors or driving (repelling) them away from the food. They are also called gustatory repellents, feeding deterrents and rejectants. Since do not feed on treated surface they die due to starvation.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 47
Groups of antifeedants Triazenes: AC 24055 has been the most widely used triazene which is a oduorless, tasteless, non-toxic chemical which inhibit feeding in chewing insects like caterpillars, cockroaches and beetles. Organotins: They are compounds containing tin. Triphenyl tin acetate is an important antifeedants in this group effective against cotton leaf worm, Colorado potato beetle, caterpillars and grass hoppers Carbamates: At substance lethal doses thiocarbamates and phenyl carbamates act as antifeedants of leaf feeding insects like caterpillars and Colorado potato beetle. Baygon is a systemic antifeedants against cotton boll weevil. Botanicals: Antifeedants from non-host plants of the pest can be used for their control The following antifeedants are produced from plants. Pyrethrum: Extracted from flowers of Chrysanthemum cinerarifolium acts as antifeedants at low doses against biting fly, Glossina sp. Neem: Extracted from leaves and fruits of neem (Azadirachta indica) is an antifeedants against many chewing pests and desert locust in particular Apple factor: Phlorizin is extracted from apple which is effective against non- apple feeding aphids. Solanum alkaloids: Leptine, tomatine and solanine are alkaloids extracted from Solanum plants and are antifeedants to leaf hoppers. Miscellaneous compounds: Compounds like copper stearate, copper resinate, mercuric chloride and Phosphon are good antifeedants. 4) Sterility technique Definition - Control of pest population achieved by releasing large number of sterilized male insects, which will compete with the normal males and reduce the insect population in subsequent generation. It is usually referred as SIT (Sterile insect technique) or SIRM (Sterile insect release method). Sterile insect release method is a genetic control method. This is also called autocidal control since insects are used against members of their own species. E.F. Knipling in 1937 in South East USA used the SIRM technique to control the screw worm fly a serious livestock pest. It is also referred as ‘Father of Male Sterility Technique’. Methods of sterilization- 1. Chemosterilants: Any chemical which interfere with the reproductive capacity of an insect. They inhibit nucleic acid synthesis, inhibit gonad development, and produce mutagenic effect which prevents the production of F1 generation. E.g. TEPA (Tetraethylenepentamine), Metapa, thiotepa, apholate, Chloro ethylamine, 5-Fluororacil, Amithopterin. 0.5% TEPA reduced housefly population. apholate solution cause male sterility in boll weevil. 2. Irradiation: Irradiation done by exposing insects to radiations, X rays and neutrons of these, radiation by Cobalt 60 is the most common method.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 48
Limitations- Not effective against insects which are prolific breeders. Sterilizing and mutagenic effect of chemosterilants and irradiation cause problem in higher animals and man (Carcinogenic and mutagenic).
5) Genetic control (Transgenic crops) Use of molecular biology techniques for the management of insect pests. The following are some strategies. 1. Wide hybridization: This technique involves transfer of genes from one species to other by conventional breeding. The genes for resistance are transferred from a different species. E.g. WBPH resistant gene has been transferred to Oryza sativa from O. officinalis. 2. Somaclonal variability: The variation observed in tissue culture derived progeny. E.g. Somaclonal variants of sorghum resistant to Spodoptera litura have been evolved. 3. Transgenic plants: Transgenic plants are plants which possess one or more additional genes. This is achieved by cloning additional genes into the plant genome by genetic engineering techniques. The added genes impart resistance to pests. Transgenic plants have been produced by addition of one or more following gene Bt. endotoxin from Bacillus thuringiensis, Protease inhibitors, Amylase inhibitors, Lectins and Enzymes. Bt. endotoxin gene: The gram positive bacteria Bacillus thuringiensis produces a crystal toxin called (delta) endotoxin. The endotoxin is a stomach poison and kills the lepidopteran insects if consumed. The gene (DNA fragment) responsible for producing endotoxin is isolated from Bt. and cloned into plants like cotton, potato, maize, etc. to produce Transgenic cotton, etc. Transgenic Bt plants Target insect pests 1. Cotton Bollworms, S. litura 2. Maize European corn borer 3. Rice Leaf folder, stem borer 4. Tobacco, Tomato Cut worms 5. Potato, Eggplant Colorado potato beetle
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 49
Toxicity of insecticides Terminology - Toxicology: Toxicology is the science which deals with study of the poisons and their effect on living organisms. Toxin/Poison: A substance which produces harmful effect when ingested /inhaled/ absorbed by the human being. Poison is a substances which when taken orally in quantities even less than 4 gm or inhaled in concentrations less than 200 parts per million (ppm) in air quickly fatal, by means other than physical or mechanical. Toxicity: Toxicity is the inherent ability of a pesticide to cause harm to a specific organism.
Types of toxicity : 1) Acute Toxicity - It is result of single dose, which causes death of insects. 2) Chronic Toxicity - It is result of cumulative effect of several small doses, each dose not produces symptoms of death. Degree of toxicity / Toxicity parameters -
1.) LD50 (Median lethal dose): LD50 defined as the amount of insecticide per unit weight which will kill 50% of the test organism / insect.
LD50 usually expressed as mg/kg body weight or g/larva or adult insect. 2.) LC50 (Median lethal concentration): LC50 defined as the percentage of toxicant required required to kill 50% of the given organism or insect. This is used when the exact dose per insect is not known, but the concentration is known. LC50 is expressed in PPM (1/1,000,000) or Percentage (1/100) 3.) LT50 (Median lethal time):LT50 is defined as the total time required to kill 50% of the insect population at a certain dose or concentration. LT50 expressed in hours or minutes. LT50 is used in field studies and also for testing insect viruses (NPV).
4.) KD50: Median knockdown dose Dose of insecticide or time required to
KT50: Median knockdown time knockdown 50% of the insects.
KD50 and KT50 are used for evaluating synthetic pyrethroids against insects.
5.) ED50: Median effective dose These terms are used to express the
EC50: Median effective concentration effectiveness of Insect Growth Regulators (IGR)
ED50 and EC50 are defined as the dose or concentration of the chemical (IGR) required to affect 50% of population and produce desired symptoms in them.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 50
Based on their LD50 values pesticides can be classified are as follows; 1) Extremely Toxic - LD50 up to 50 mg/kg. e.g Phorate.
2) Highly Toxic - LD50 between 51-500 mg/kg. e.g. Phosphamidon.
3) Moderately Toxic - LD50 between 501-5000 mg/kg. e.g. Dimethoate.
4) Slightly Toxic - LD50 = 5000 mg/kg and above. e.g. Malathion, Carbaryl.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 51
Formulations of insecticides Formulation: - Incorporation of pesticide into a suitable carrier, solvent and the supplementary agents or adjuvant is known as formulation. It is mixture of active and inactive ingredients. Necessity of formulation - i) Pure pesticide is costly; the formulations give cheaper & safe form of insecticide. ii) High concentrations may prove to be phototoxic. iii) Easy distribution on large area due to large volume formulation. iv) Pure material is highly hazardous in handling, formulation decreases the residual hazards. v) To improve effectiveness of insecticides. Types of Formulations - Liquid formulation Dry Formulation Emulsifiable Concentrate (EC) Dustable Powder (DP) Solution (SL) Wettable Powder (WP) Suspension Concentrate (SC) Soluble Powder (SP) Concentrate Emulsion (EW) Water Dispersible Granule (WG) Micro emulsion (ME) Granule (G) Aerosol (Aer) Soluble Liquid (SL) Ultra-Low Volume Liquid (ULV) Oil Dispersion (OD)
Dry Formulation 1) Dusts: In this formulation the toxicant is diluted either by mixing with or by impregnation on carrier. The carrier may be an organic flour (Walnut shell flour, wood bark) or pulverized mineral (Sulphur, Lime, Gypsum, talc) or clay (attapulgite, bentonites, kaolins). The toxicant in a dust formulation ranges from 065% to 25%. Those having particle size less than 100 micron. Dust formulation must be done in a calm weather and early in the morning when plant is wet with dew. It is denoted by ‘D’ E.g. Lindane 0.65%, Malathion5%, Carbaryl 10%.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 52
Advantages: i) Dust can be used where water supply is difficult & inadequate. ii) Less quantity required as compared to spray material. iii) Application is faster than spray solution. iv) Due to the light in weight it can be used in hilly areas or muddy fields. v) It is cheaper and requires less cost. Disadvantages: i) Drift problems - dust are likely to blow away along with wind velocity. ii) Due to the less diposition on plants its efficiency is decreases. 2) Wettable powders/Water dispersal powders: WP is the powdered formulation which gives stable suspension when diluted with water. The toxicant/active ingredient in a formulation ranges from 15% to 95%. It is formulated by blending the toxicant with diluents such as attapulgite, a surface active agents and auxiliary material such as sodium salt & sticker is also added. It is more effective than dust. It is denoted by ‘WP/WDP’ E.g. Carbaryl 50% WP. 3) Granules: It is a granular formulation of insecticide composed of inert material (Carrier, diluents like vermiculite) or vegetable carrier impregnated. or fused with toxicant. The particle size ranges from 250 to 1250 microns. The formulation contains 2 to 10% concentration of toxicant. This formulation is used for the control of weeds, plant diseases and insect-pests, nematodes, snails & slugs, rodents. It is denoted by ‘G’. E.g. Phorate 10%, Carbofuran 3%, Quinalphos 5%. Advantages: i) No undue loss of insecticide. ii) Undesirable contamination is prevented. iii) Water is not requiring for application. iv) Less harmful to natural enemies. Disadvantages: i) Not as effective as spray. ii) Scorching may occur if toxicant in concentrated. 4) Soluble Powder (SP)
Similar to the Wettable powder, but dissolve readily and forms a true solution. It composed of pesticides, water soluble diluents, Wetting and dispersing agents. E.g. Acephate75 SP. 5) Water Dispersible Granule (WG)
It composed of active ingredients, diluents, Wetting and dispersing agents. E.g. Thiomethoxam 25 WG
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 53
Liquid formulation
1) Emulsifiable Concentrate:
The formulation contains the toxicant, a solvent of toxicant and an emulsifying agent. It is clear solution which gives an emulsion of oil-in water type when diluted with water to spray. When sprayed the solvent evaporates quickly leaving a deposits of toxicant from which water also evaporated. Emulsifying agents used are alkaline soap, organic amines, carbohydrates, gum, lipids, proteins etc. It is denoted by ‘EC’. E.g. Chlorpyriphos 20 EC, Profenophos 50 EC. Advantages: i) Dilution of chemical with water is possible. ii) Better contact with insect cuticle. iii) Surface tension of the spray reduced. iv) Even distribution of insecticides possible. 2) Solution: (SL) Toxicants dissolved in organic solvent such as Amyl acetate, Carbon tetrachloride, Ethylene dichloride, Xylene, Petroleum & Kerosene. It is mostly used to control household pests & aquatic insects like mosquitoes. It is denoted by ‘SL’. E.g. Imidacloprid 17.8SL 3) Aerosol: The toxicant is suspended in mixture particles (Size ranges from 0.1 to 50 microns) in air as a fog or mist. This is achieved by i) burning the toxicant with heat, ii) the toxicant dissolved in liquefied gas. When released the toxicant particles to float in air with the rapid evaporation of the released gas. Effective against flying insects and the pests in dense foliage. E.g. Aerosol bomb.
4) Fumigants: - A chemical compound which is volatile at ordinary temperature & sufficiently toxic is known as fumigants. It is used against stored grain pest & nematodes. E.g. Aluminium phosphide tablets, Ethylene dibromide, ED/CT Mixtures.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 54
Adjuvants : Supplementary agents which do not contribute directly to the toxic effect of pesticide but are used for improving physical condition of pesticides so that pesticide become more effective in action. Types of Adjuvants . Dust carriers - Organic flour, lime, gypsum, talc, kaolin,& volcanic ash. . Solvents - Amyl acetate, Carbon tetrachloride, Ethylene dichloride, Xylene, Petroleum & Kerosene, pin oil. . Dispersing agents - Polyfon H, Blancol, Daxad 21. . Emulsifiers (Emulsifying agents) - o It is surface active agents. o The principal function is to modify the properties. o They may be O/W (oil in water type) or W/O (water in oil type). o The pesticidal emulsions are oil in water type. o E.g. Alkaline soaps, Carbohydrates, proteins, organic amines. . Wetting and spreading agents - Soaps, Teepol, Tergitos, Triton X-100. . Stickers - Synergists: Chemicals which by themselves are nontoxic or only slightly toxic but when mixed with pesticides increase their toxicity. E.g. Sesamin, Sulphoxide. Antagonistic: The chemicals when mixed together reduce the toxicity of mixture
PLANT PROTECTION APPLIANCES Dusters: - Appliances/equipment that is used for applying dry dust formulations of pesticides is called as dusters. Parts of typical duster: - Hopper or Container- To hold the dust. Blower or Bellows- To create air current for ejecting out the dust. Operating mechanisms- Required to work equipment. Agitator- To stir the dust in the hopper. Feed mechanisms Discharge line Mounting.
Types of duster-
1. Rotary dusters: They are also known as crank dusters and fan type dusters. They vary in design and may be shoulder mounted, back mounted or belly mounted. The capacity of rotary duster is 4-5 kg dust. They are used for dusting field crops, vegetables and small trees and bushes in orchards. The efficiency is 1 to 1.5 per day. 2. Knapsack dusters: The capacity of knapsack duster is 2 to 5 kg. They are used for low crops and for spot application.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 55
3. Power operated dusters: This may be from Knapsack types with engine motive power to powerful row crop or trees dusters pulled by tractor. These dusters are useful for covering larger area and tall trees. 4. Plunger duster: The capacity of plunger duster is ½ kg. It is used kitchen garden. 5. Bellow duster :
Sprayers-
Principle: The function of a sprayer is to atomize the spray fluid into small droplets and eject it with some force. Parts of typical sprayer: - Tank: To hold the spray fluid during spraying. Pump: The pump is necessary for creating the energy required for atomization of spray fluid. Agitator: Used for dispersing the pesticide uniformly. Pressure gauge: It is connected to the pipe line near the nozzle usually. Valves: They govern the direction of the flow of the spray fluid. Filter: This is provided mainly to protect the pump from abrasion, to avoid interference with the function of valves and to prevent blocking of nozzles. Pressure chamber: It prevents fluctuation in the pressure & records it. Hose: For conduction of the spray fluid from sprayer to lance. Spray lance: It is useful for spraying under surface of leaf. Cut-off valve: It is used to shut off the liquid. Spray boom: Spray bars carrying more than one nozzle is known as spray booms. Nozzle: It breaks the liquid into droplets and spread them into spray droplets. It consists of Body, Cap, Swirl plate, Washer (sealer), Stainer.
Types of nozzles- Fan spray nozzles: It is recommended for spraying flat surface such as soil. Usually for spraying herbicides. Hollow cone (ring) nozzles: It is used for insecticide and fungicide spraying. Solid cone nozzles: It is used for herbicide spraying. Flood jet nozzle: It is used for herbicide spraying.
Types of sprayers – A. Hand Sprayer or Manually operated-
Hydraulic sprayers- 1. Hand syringe: It is useful to operate only a small area. It is single acting pump working on the principle of cycle pump.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 56
2. Hand sprayer: The tank capacity is 0.5 to 1.0 litres. It also used for spraying small kitchen garden. 3. Bucket pump sprayer (Stirrur pump): Mostly buckets are used as containers for holding spray fluid at time of spraying. This is suited for small scale spraying. About 1 to 1.5 hectare area can be covered in a one day. 4. Knapsack sprayer: Also known as Backpack. The tank capacity is 10 to 14 litre capacity. The pressure is developed with help of level handle. They are useful for small scale spraying or spot spraying gardens, vegetables plots, vineyards etc. About 0.5 hectare area can be covered in a one day. 5. Rocker sprayer: It is used for spraying fruit trees and tall crops. 6. Foot sprayer (pedal pump): Used for spraying field as well as fruit crops. Principle is same as in case of rocker sprayer but it is operated by foot instead of hand. About 1 to 1.5 hectare area can be covered in a one day.
B. Manually operated compression sprayers: These are also known as pneumatic sprayers. a. Pneumatic hand sprayer: It is mostly used in glass houses and kitchen garden. b. Pneumatic knapsack sprayer: It is also known as shoulder mounted sprayer. The capacity is 18 liter. It is used for field and vegetable plots, flower garden. C. Power Operated sprayer: a. Mist blower cum duster- (Motorized knapsack sprayer)(Gaseous energy sprayer):- Worked by petrol driven engine. It produces very fine droplet size 50 to 150 micron. About cover 3 hectare areas in a one day. b. Portable power sprayer- Useful for large scale spraying in plantation, orchard, flowers and vegetables gardens. D. Ultra-low volume sprayer (ULV) (Hand carried, battery operated spinning dis- sprayer): Here the pesticides are applied as such or with less than 5 liters spray fluid produces fine droplets (80 μm). E. Electrodyn sprayer (EDS): Electrodyn sprayer is completely a new system of spraying for the controlled droplet application of chemicals (CDA).
Other appliances:- 1. Soil injecting gun- It is used for fumigating the soil at different depths to control the nematodes and soil insects. 2. Bird scarer- It is mechanical device produced loud noise at regular interval and used to scare away the birds. It consists of a big chamber to hold calcium carbide and water. Due to the combustion of this mixture acetylene gas is produce. 3. Flame thrower- It is ordinary pneumatic sprayer filled with kerosene for producing flame. It is used to destroy locust swarm, hairy caterpillars. 4. Rat fumigation pump (Cynogas pump) - It is used for blowing calcium cyanide into rat holes, termite mounds. This kills rats, mites, termites. 5. Granular applicator- Use for granular application.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 57
SEMIO-CHEMICALS
The word “Semion” means “Signal”. Chemicals involved in the communication are termed as a semiochemicals. Semiochemicals are chemical substances that mediate communication between organisms. Most secreted by exocrine glands in insects. Can be divided into two groups based on who `sends’ a massage and who `received’. Semiochemicals may be classified into Pheromones (intraspecific semiochemicals) and Allelochemicals (interspecific semiochemicals). i) Intraspecific semiochemicals: - These are responsible for behavioral changes among individuals of the species. E.g. Pheromones ii) Interspecific semiochemicals: - These are responsible for behavioral changes between the individuals of different species. E.g. Allelochemicals
Pheromone Pherein = to carry, Hormone = to excite In 1959, German chemists Karlson and Luscher coined the term pheromone. Pheromones are exocrine secretions of insects which are used for communication among different individuals of the species (Karlson and Luscher, 1959). Definition: - A substance that is secreted by an organism to the outside environment and cause specific reaction in a receiving organism of the same species.
Pheromones can be classified into 2 groups
1) Primer pheromones: Primer initiates changes in development, such as maturation. They act through gustatory (taste) sensilla. e. g. Caste determination and reproduction in social insects like ants, bees, wasps, and termites are mediated by primer pheromones. These pheromones are not of much practical value in IPM. 2) Releaser pheromones: Releaser which induce immediate behavioural change. This pheromones act through olfactory (smell) sensilla and directly act on the central nervous system of the recipient and modify their behavior. They can be successfully used in pest management programme. Releaser pheromones may be further subdivided into Sex pheromones Aggregation pheromones Alarm pheromones Trail pheromones 1.) Sex pheromones A substance generally produces by a female to attract the male for the purpose of mating.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 58
In 1959, A. A. Butenandt isolated and identified the first pheromone, a sex attractant from silkworm moths, Bombykol. They are most commonly released by females but may be released by males also. Insects order producing the sex pheromones Lepidoptera, Orthoptera, Dictyoptera, Diptera, Coleoptera, Hymenoptera, Hemiptera, Neuroptera and mecoptera. In Lepidoptera, sex pheromone system is highly evolved. Pheromone producing glands: In Lepidoptera they are produced by eversible glands at the tip of the abdomen of the females. Aphrodisiac glands of male insects are present as scent brushes at the tip of the abdomen. E. g. Male butterfly. Andraconia is glandular scales on wings of male moths producing aphrodisiacs. Aphrodisiacs are substances that aid in courtship of the insects after the two sexes are brought together. In many cases males produce aphrodisiacs. Pheromone reception: Female sex pheromones are usually received by olfactory sensillae on male antennae. In pheromone perceiving insects, the antennae of male moths are larger and greatly branched than female moths to accommodate numerous olfactory sensilla. Chemical nature of sex pheromones: In general pheromones have a large number of carbon atoms and high molecular weight. It is a primary alcohol. It is in slow release dispensers (rubber septa hollow fibers) that are used as lures in traps of various designs. . The following are some of the female sex pheromones identified in insects Sr. No. Name of the Insect Pheromone 1. Silkworm, Bombyx mori Bombykol 2. Gypsy moth, Porthesia dispar Gyplure, disparlure 3. Pink bollworm ,Pectinophora gossypiella Pectinolure, Gossyplure 4. Cabbage looper, Trichoplusia ni GossyplureLooplure 5. Tobacco cutworm, Spodoptera litura Spodolure, 6. Gram pod borer, Helicoverpa armigera Helilure 7. Honey bee queen, Apis sp. Queen’s substance 8. Spotted/Spiny bollworm Earis vitella Erilure 9. Diamond Back Moth DBM Lure 10 Brinjal shoot & fruit borer Leucinolure . Examples of male sex pheromones o Cotton boll weevil (Grandlure), Cabbage looper, Mediterranean fruit fly
2.) Aggregation pheromones A substance produces by the one or both sexes that bring both sexes together for feeding and reproduction. These are released by members of one sex only but elicit responses in members of both sexes of a species. e. g. Bark and ambrosia beetles. Generally found in Coleoptera & Dictyoptera order.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 59
3.) Alarm pheromones A substance produces by an insect to repel and disperse other insects in the areas. These pheromones are reported in Homoptera, Isoptera and Hymenoptera. E. g. Poison glands in ants, Cephalic glands in termites, Sting and mandibular glands of workers bees and cornicles in aphids. An individual also release them when an enemy attacks. 4.) Trail pheromones Trail marking pheromones are substance of low persistence that are released and perceived by individuals in trail. These pheromones are specially found in social insects like hymenopterans and termites. The ants (Formic rufa) use formic acids as a trail marker. They facilitate migration of colony to new site in search of food. Uses of pheromones Monitoring Mass trapping Mating disruption
Allelochemicals
R. H. Whittaker coined the term Allelochemicals in 1970. It is defined as non-nutrient substance originating from an organism (Plants & Animals), which affect the behavior condition or ecological welfare of organisms of another species. Allelochemicals affects the behavior, growth and development of an insects as well as their natural enemies. Allelochemicals are divided in following sub-categories. Allomones Kairomones Synomones Apneumones
Allomones - A chemical substances produce by organisms that favourable to the emitter but not to receiver e.g. Venon secreted by social wasps Kairomones- A chemical substances produce by organisms that favourable to the receiver but not to emitter. Synomones- A chemical substances produce by organisms that favourable to the both receiver and emitter. Apneumones- A chemical substances produce by non-living material that favourable to the receiving organisms but detrimental to an organisms of another species that is found on or in non-living material.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 60
THE INSECTICIDES ACT, 1968 The insecticides act was passed by the parliament of India in 1968. There were 38 sections of this act in which the sections 4, 7, 8 & 36 were enforced from 1/3/1971 and remaining from 1/8/1971. An act to regulate the import, manufacture, sale, transport, distribution and use of insecticides with a view to prevent risk to human beings on animals and for matters connected therewith.
Salient features of the Insecticides Act Compulsory registration of the product at the Central level and licenses for manufacture, formulation and sale at state level. Inter – departmental / ministerial / organizational co-ordination is achieved by a high level advisory board “Central Insecticides Board” with 24 members (to be raised to 29 by an amendment) drawn from various fields having expert knowledge of the subject. “Registration Committee” to look after the registration aspects of all Insecticides. Establishment of enforcement machinery like Insecticide Analysts and Insecticide Inspectors by the Central or State Government. Establishment of Central Laboratory Power to prohibit the import, manufacture, and sale of pesticides and also confiscate the stocks. The offences are punishable and size and other penalties are prescribed. Both the Central and State Governments are empowered to make rules, prescribe forms and fees.
The Central Insecticides Board (CIB) The Central Insecticides Board advices on matters relating to: The risk to human beings or animals involved in the use of insecticides and the safety measures necessary to prevent such risk. The manufacture, sale, storage, transport, distribution of insecticides with a view to ensure safety to human beings and animals. Board members The Director General Health Services ➜ Chairman The Drugs Controller, India The Plant Protection Adviser to the Government of India The Director General, ICAR The Director General, ICMR Totally 24 members – others from various other fields such as BIS, Animal husbandry, Pharmacology, Fisheries, Wild life etc
The Registration Committee (RC) RC comprises a Chairman and five members. Among them are: 1. Deputy Director General, Crop Sciences, ICAR-Chairman 2. Drugs Controller, India 3. Plant Protection Adviser to the Government of India Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
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Role of RC To register insecticides after scrutinizing them with regard to efficacy and safety. Registration of Insecticides - When applied for registration, the RC allots a registration number within a period of 12 months. When pesticide registered for first time in India, provisional registration for two years given initially. After data generation full registration allowed.
The Central Insecticides Laboratory (CIL) CIL carries out the analysis relating to insecticide registration and other matters. Insecticide Inspectors Central or State Government appoints person called Insecticide Inspector who is empowered. a. To enter and search premises b. To stop the distribution or sale or use of insecticide c. Take samples of insecticide and send for analysis The Insecticides Rules, 1971 There are nine chapters in the insecticide rule, 1971 relating to the functions of CIB, RC, CIL, grant of licenses, packing, labelling, first aid, antidote protective clothing etc., It has 46 rules.
Insecticide residues and waiting period Residues- The toxicant that remains in the environment (like soil, water, plant harvested produce, etc.) after the application of insecticides. Persistence- The duration of retention is called persistence. Waiting period- is the minimum period allowed between time of application of pesticide and harvest of commodities. MRL (maximum residue limits) - In order to allow the toxicant residue level to come below MRL.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 62
Phytotoxicity and compatibility of insecticides
Phytotoxicity Phytotoxic means harmful or lethal to plant. Phytotoxicity is the degree to which a chemical or other compound is toxic to plants. Compatibility Cox (1941) coined the term compatibility. In pest control treatment, two or more pesticides, fungicides or even fertilizers are sprayed or applied in the same operation to minimize cost of labour. Before mixing two different chemicals, their physical and chemical properties should be well understood. Incompatible pesticides should not be mixed. Only compatible pesticides can be mixed. When two or more ingredients a successful spray or dust mixture they are said to be complete. Incompatibility of pesticides may be of following types Chemical incompatibility Chemical compounds in the two pesticides react with another producing a different compound, reducing the pesticidal activity of the pesticides (Degradation of active ingredient). Biological incompatibility (Phytotoxic incompatibility) The mixed product exhibit phytotoxic action, which independently is not phytotoxic. Physical incompatibility The physical form of the pesticides change, and one of them become unstable or hazardous for application. Gray (1914) worked on pesticides combination and also he divided the mixtures of insecticides and fungicides into 5 classes designated by letters A-I, A, B, C, and D. Insecticides mixtures: - Recently combination of insecticides are recommended to control insect pest which are resistant to major pesticides that are used commonly because these insecticides mixtures are usually prepared which have different modes of action i.e. organophosphates or carbamates with synthetic pyrethroids so that the development of resistance to these combinations is extremely rare but they are not prepared by combining organophosphates and carbamates which have same mode of action.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 63
Table of insecticides mixture Sr. No. Insecticides Trade Name 1 Chlorpyriphos 50% EC + Cypermethrine 5% Nurelle D 505 EC 2 Profenophos 40% EC + Cypermethrine 5% EC Polytrin C 44EC 3 Chlorpyriphos 16% EC + Alphamethrin 1% Duet 17 EC EC 4 Deltamethrin 1% EC + Triazophos 35% EC Spark 36 EC 5 Ethion 40% EC + Chlorpyriphos 5% EC Nagata 45 EC
First aid: In cane of suspected poisoning; call on the physician immediately. Before calling on a doctor, first aid treatments can be done by any person.
Swallowed poison - During vomiting, head should be faced downwards. Stomach content should be removed within 4 h of poisoning. To give a soothing effect, give either egg mixed with water, gelatin, butter, cream, milk, mashed potato. In case of nicotine poisoning, give coffee or strong tea.
Skin contamination - Contaminated clothes should be removed. Thoroughly wash with soap and water.
Inhaled poison - Person should be moved to a ventilated place after loosing the tight cloths. Avoid applying frequent pressure on the chest.
Antidotes :- Definition: - The substances that are used to cure the cases of insecticidal poisoning are known as antidotes. There are two types of antidotes; 1.) Universal Antidotes - It contains 2 parts of activated charcoal + 1 part of magnesium oxide + 1 part of tannic acid + ½ glass of warm water. It is useful for acids and heavy metal poisoning. 2.) Specific Antidotes - Which varies with toxicant as follows;
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 64
Antidotes and other medicine for treatment in pesticide poisoning
S. Antidote / Medicine Used in poisoning due to No. 1. Common salt (Sodium chloride) Stomach poison in general
2. Activated charcoal (7g) in warm Stomach poison in general
Magnesium oxide (3.5g) water
Tannic acid (3.5g)
3. Gelatin (18 g in water) or Flour or milk Stomach poison in general power (or) Sodium thiosulphate
4. Calcium gluconate Chlorinated insecticide, Carbon tetrachloride, ethylene dichloride, Mercurial compound
5. Phenobarbital (or) Pentobarbital Stomach poison of intravenous administration chlorinated hydrocarbon
6. Sodium bicarbonate Sintsecomtiacchid peos ison of organophosphate
7. Atropine sulphate (2-4 mg intramuscular Ocormgapnophooundss phate Compounds / intravenous administration) or PAM (Pyridine-Z aldoxime-N-methliodide)
8. Atropine sulphate (2-4 mg Carbamates intramuscular / intravenous administration)
9. Phenobarbital Synthetic pyrethoid
10. Potassium permanganate Nicotine, Zinc phosphide
11. Vitamin K1 and K2 Warfarin, Zinc phosphide
12. epinephrine Methlyl bromide
13. Methyl nitrite ampule Cyanides
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 65
APICULTURE Definition: The art of scientific beekeeping for the profitable production of honey and wax is called apiculture. Important Species producing Honey(Family : Apidae, Order : Hymenoptera)
Common name Scientific name Honey/Year/Colony
Indian honeybee Apisceranaindica 3-5 kg
Italian/Europeahoney bee Apismellifera 45-180 kg
Giant or Rock honey bee Apisdorsata 27-36 kg
Little bee or Dwarf bee Apis florae 0.45-0.50 kg
Mosquito or Dammer bee Melipona/ Trigona irridipennis Traces
Darling of bee keeping industry world over - Italian bee: Apismellifera
Why the bees are important:- BEE PRODUCTS - Honey Bees, Wax, Royal Jelly, Bee Venom, Propolis. Composition of fully ripened honey- Lrvulose, Dextrose, Sucrose, Dextrins, Minerals, Water, Undetermined (Enzymes, Vitamins, Pigments, etc.). Pigments - Carotene, Chlorophyll, Xanthophyll Minerals include-Potassium, Calcium, Phosphorus, Sodium, Magnesium, Manganese, Copper, Sulphur, Silica, Iron. Vitamins-Vit. B1 (Thiamine), B2 (Riboflavin), Nicotinic acid, Vit.K, Folic acid, Ascorbic acid, Pantothenic acid.
Every honey bee colony comprises of a single queen, a few hundred drones and several thousand worker castes of honey bees. Queen is a fertile, functional female, worker is a sterile female and the drone is a male insect.
Division of labor- Queen -Reproductive female Drone - Reproductive Male Worker -Degenerative female
Duties of a queen- 1. The only individual which lays eggs in a colony. (Mother of all bees). 2. Five to Ten days after emergence, she mates with drones in one or more nuptial flights. 3. The secretion from mandibular gland of the queen is called queen’s substance. 4. The queen can lay either fertilized or sterile eggs depending on the requirement
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 66
Duties of a drone- 1. Their important duty is to fertilize the queen. 2. They also help in maintenance of hive temperature. 3. They cannot collect nectar / pollen and they do not possess a sting.
Importance of worker honey bees- 1. Workers are imperfectly developed females. From the third day of development their ovipositor modified in to poison sting to defend the colony. 2. There are 99 percent workers individuals in each colony 3. In 6 weeks (42 Days) life span they totally serve for the welfare of colony First 3 weeks (first half of life) – indoor works a. Build comb with wax secretion from wax glands. b. Feed the young larvae with royal jelly secreted from hypopharyngeal gland. c. Feed older larvae with bee-bread (pollen+ honey) d. Feeding and attending queen & Feeding drones. f. Cleaning, ventilating and cooling the hive & Guarding the hive. h. Evaporating nectar and storing honey. Later 3 Weeks (second half of life) – out door works 1. Collecting nectar, pollen, propolis and water. 2. Ripening honey in honey stomach. Worker bees have following glands – Gland Secretion 1. Pharyngeal glands Royal jelly / Bee milk 2. Wax gland Wax 3. Acid glands Bee venom 4. Mandibular glands Wax softening fluid
. Life cycle of honey bee
Caste Egg Stage Grub stage Pupal stage Total life Adult (Days) (Days) (Days) cycle(Days) longevity
Queen 3 5 7-8 15-16 2-3 Years
Worker 3 4-5 11-12 18-20 6 Weeks
Drone 3 7 14 24 3 Months
Apiary :- The place where the bee and bee hives placed for the production of honey is called apiary The modern bee keeping became possible after the discovery of movable frame hive in 1851 by Rerd. L. L. Langstroth. In India beekeeping was introduced in 1882 in Bengal.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 67
Reverant Lorenzo Lorraine Langstroth (1810-1895) (Bee Hive)
The ISI Newton frame hive Modern Bee hive
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 68
Following types of hives are in use 1. Langstroth frame hive - For Italian bees. 2. Newton frame hive - Most popular for Indian honey bees.
Beekeeping appliances Following equipment are essential to organize the beekeeping on modern lines. 1. Hives: - The modern hive; the home of the bees. The hive is wooden structure consisting of several parts. There are three parts of hives. i) The langstroth hive, ii) The jeolikote hive iii) The ISI hive (Newton frame hive). The langstroth hive is recommended for Italian bees where as other two are used for Indian bees. Other appliances:- 1) Bee veil-(mosquito netting) - mosquito 2) Hand gloves-during apiary operation. attack. 3) Queen Excluder-separate brood chamber 4) Queen’s cage-introduction of new from super. queen in the new colony. 5) Queen cell protector-protection to 6) Bee escaper-funnel shaped structure developing queen (cane shaped structure for the bees to go out of super. of wire). 7) Comb foundation sheet-Sheet of bees 8) Honey extractor-centrifugal machine wax on both sides. It is fitted on frame. with revolving chamber into which frames are fit. 9) Feeder-keeping of liquid food for bees. 10) Overall-white cloth of apiary working person. 11) Ant barrier-prevent attack of ants 12) Honey tanks-storage of honey. 13) Painting the hive-to reflects sunlight. 14) Drone trap-trapping of drones or queen. Pest of Honey bee Greater Wax moth Lesser Wax moth Wax beetle Yellow banded hornate Bee hunter wasp Myna Bee eater Diseases of Honey bee Acarine disease / Isle of Wight (Mite) Nosema disease (Protozoa) Amoebic disease (Protozoa)
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 69
American foul brood (Bacteria) European foul brood (Bacteria) Chalk brood (Fungi) Stone brood (Fungi) Thai Sac brood (Virus) CCD - Colony collapse disease: It occurs due to adverse environmental conditions or mall nutrition.
Dance Language In Honey Bee-(Prof. Karl Von Frisch) 1. Round Dance: It consist circling to the left and then to the right and then repeating it over. The purpose of the dance to inform other bees the source of food located within the distance of 50 meters.
2. Tail wagging Dance: In this type of dance a worker bee first does a half circle and then moves in straight line and then complete the other half circles. The key part of the dance is the run up in the straight line between the two half circles. While tacking this path the bee waggles her abdomen from side to side. The purpose of the dance to inform other bees the source of food located more than the distance of 50 meters
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 70
How the honey is produce by honey bees Bees have amazing communication and organizational skills. When a bee finds a good source of nectar it will share this with the hive by performing a 'waggle' dance. Bees start making honey, which is their food, by visiting flowers. They collect a sugary juice called nectar from the blossom by sucking it out with their tongues. They store it in what's called their honey stomach, which is different from their food stomach. When they have a full load, they fly back to the hive & The bee then moves this watery honey mix from its tummy, into its mouth, and then into the honeycombs of the hive. But this new nectar mix is still quite watery & then bees naturally broken down into simple sugars and stored / deposited in the honeycombs. The process of ripening by which bees convert nectar into honey consist of converting sucrose in nectar into glucose, by the enzymes Invertase & evaporation of excess water to prevent fermentation. This process takes place in honey cells of the comb where nectar is deposited. The honey is concentrated (thickened) by evaporation of water caused by fanning of wings by hive bees. The bees consume nectar along with saliva, and afterwards regurgitate into honey cells of the comb. 100000-200000 trips are needed to collect nectar enough to produce 1kg honey. Terms & facts related to Apiculture 1. Swarming: The process of leaving off the colony by queen with some of the worker bees to establish colony at newer place is called swarming. 2. Absconding: Migration of complete colony from one to another place due to some unfavorable weather conditions of life such as shortage of food, attack of enemies is termed as absconding. 3. Supersedure: When egg laying capacity of the old queen is lost or it suddenly dies, a new and young vigorous queen takes the position of old queen in a colony is known as Supersedure. 4. Honey bees are social in behavior. 5. Unfertilized eggs of honey bee produce male, whereas fertilized eggs produce workers or queen bees. 6. In honey bees queen substance is secreted from mandibular glands. 7. The workers bees’ milk (Royal jelly) is secretion of pharyngeal glands which are located in the head. 8. The bee venom is ecto harmone its ingredients are Melittin, phospholipase A, Hyaluronidase, histamine, Acid phosphatase. 9. Propolis is known as bee glue which is sticky substance for repair comb. 10. Pinocembrin is one antioxidant only found in honey. 11. Males of honey bees are called as drones.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 71
SERICULTURE
(French word Seris = Silk, Culture = raising) Sericulture: - The art of manufacturing commercial silk by tending of silkworm from egg to cocoon. Silk: - It is the secretion of spinneret of the caterpillars of silkworm about to pupate.
Important Species silkworm producing silk( Order : Lepidoptera)
Sr. Common name Scientific name Family Host Botanical Name No. Plants 1 Mulberry silkworm Bombyx mori Bombycidae Mulberry Morus alba
2 Eri silkworm Philosomia ricini Saturniidae Castor Ricinus communis
3 Tassar silkworm Anthreaea mylitta Saturniidae Shisav, Dalbergia Sp. Arjun, Terminalia polyantha Ber Zizyphus mauritiana 4 Muga silkworm Anthrea assama Saturniidae Som & Machilus bombycina, Soalu Litsaea polyantha
Rearing of Mulberry silkworm:-
Mulberry cultivation (Moriculture):- Cultivation of mulberry plant (Morus alba) called as moriculture.
1) Choice of variety:-The quality & quantity of silk produced by silk worm depend on the mulberry leaves feed to them. The varieties recommended for Maharashtra are Kanva-2, S-45, and S-54.
2.) Planting Method: - Mulberry is propagated by seed, root graft & stem cutting. Planting method:-Row & pit system. Spacing:-60×30cm in row system. Rainfall:-700-1000mm. Temperature:-25°c-30°c. Humidity:-70-85%. Harvesting:-leaf picking, branch cutting & top shoot harvesting. The tender leaves are given to the younger larvae, mature leaves to the older larvae. The entire branch cutting offered to third instar larvae.
3.) Production of Silk:- a) Climate: -Places like Kashmir, Karnataka are suitable. July- Feb & Oct-Feb in Maharashtra (Western Ghats). The worm does not thrive well if the temp is above 32.5°cor below15°c.Temperature & humidity has great effect ton silkworm rearing. Optimum temperature for rearing is 27-29°c & relative humidity is 65-70°c. b) Equipment/materials:- Mulberry planting material, implements, tools, land, etc. Bamboo tray for rearing caterpillars. Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 72
An iron or wooden shelf for keeping trays. Bamboo basket with lid for keeping cocoons & rearing full bred worms about to spin the cocoon. Two baskets are sufficient for 1000 spinning worms are sufficient. Dry straw grass, paper, mango leaves, should be kept in bamboo basket in which caterpillar about to pupate are kept. Glazed paper for egg laying. Small circular baskets for keeping eggs. c) Rearing: - I. Feeding schedule: -After hatching the young tiny larvae should be fed 2 times in a day with tender leaves, after first & second molt 3 times a day, after third molt 4 times a day. After fourth moult 5 times a day (twice at night). Larvae of different instar are kept in different batches. II. Careat the moulting:-Moulting worms should not be disturbed. Full grown worms should be transferred to Bamboo flat baskets; Chandrika covered with lids. It can be taken for granted that rearing is successful if the mortality does not exceed 15%. d) Precautions:- In summer trays should be covered with moist cloth. Fresh delicate leaves should only be fed at proper times. Keep all equipment vary clean & hygienic. Select disease free eggs for rearing (most important).
e) Preparation of silk:- Expose pupa to hot sun for 3 days after pupation is completed. Keep part of cocoons for maintenance of brood & allow them to emerge. Soak the boiled cocoons in boiling water or treat them with steam for 20-30 minutes. Dry the cocoons to avoid purification & Peel them & obtain silk. Rearing of Tassar silk worm 1. Newly hatched larvae can be directly transferred to tree branches. 2. A small twig should be placed over each newly hatched larva and then tied on the tree for uniform distribution. 3. The first instar can be reared under controlled conditions on cut twig, kept in the cage. 4. The bottom of the twigs should be immersed in water kept in a bottle or earthen vessels to prevent quick drying of leaves. 5. The rearing of the larvae continued up to 3rd instar under nylon netting. 6. Fourth instar can be transferred to forest plantation. Moulting of I to IV instars occur in 3-4,5-7,7-8 and 8-10 days respectively while the V instar takes 15 days during which it feed voraciously to become full grown at maturity it measures 12-15cm and weighs 45 to 50g. 7. The cocoons are collected by tribal and stifled. Stifling and reeling of cocoons 1. Tassar silkworm cocoons are rather hard and they are first soaked in 5%
Na2CO3 solution for 18 hrs. 2. They are then subjected to steam cooking in pressure chamber for 2 ½ hours. 3. After 24 hours, the cocoon washed in 0.5% formalin for 15-20 minutes.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 73
4. These steps give silk fibers a greater tensile strength. 5. Cocoons are squeezed to expel water and reeled on a reeling machine. 6. Threads from 4 cocoons used for reeling.
Diseases of Silk worms 1. Pebrine (Protozoa), 2. Flacherie (Bacteria), 3. Grasserie/ Jaundice (Virus), 4. Muscardine (Fungi), 5. Septicemia (Bacteria) Uzi fly is major pest of silkworm
Sericulture Research Institutes Name of the Institute Place
Central silk board Bengaluru, Karnataka
Central Sericulture Research and Training Institute Mysore, Karnataka
Central Muga - Eri Research and Training Institute Titibar, Assam
Central Tasar Research and Training Institute Ranchi, Zarkhand
Central Sericulture Research Station Behrampur, Odisha
Important Terms & Facts In Sericulture Silk fiber (Bave) is made up of two proteins Viz. Fibroin and sericin at 75 and 25 parts on weight basis A bale of silk from India weights 50 Kg Newly hatched silkworms called as kegs, Chawki, ants etc. Hot HCL treatment is use to break the egg dormancy The place where the disease free eggs produced on scientific lines is called as Grainage. Mulberry silk worm is Monophagous insect Tassar silk worms diapause in pupal stage having peduncle to cocoon Silk glands are ectodermal in origin To produce one kg raw silk 10 to 12 kg cocoons required To produce one kg silk 120 to 160 kg leafy material required Denier is the weight of 9000m long silk thread in gram The silk thread reeled from two cocoons is called as Dupion Silk Karnataka is the leading state in mulberry silk production China is the world’s largest silk producing country
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 74
LAC CULTURE Lac: Lac is resinous secretion of a tiny lac insect (Kerria lacca). Lac culture - Lac culture is a science which deals with rearing of lac insects and production of commercial lac. Family: -Lacciferidae Order: -Hemiptera.
Host Plants of Lac Insect- Palas, Kusum, Ber, Babul, Pipal, Khair, Sal, Tur etc. Life cycle of lac insect A healthy female produces 300-1000 nymphs. The crawlers emerge from the female cells moves on host tree in search of food they settle the place. A day or so after settling the nymph start secreting resin from resin glands which are distributed all over the body except mouth parts, two breathing tubes & anus. The nymphs moult thrice, after the first moult both male and female loose their legs, antennae and eyes and become degenerate. During the second moult males regenerate the appendages while a female doesn’t. Males developed as winged ones which live only for 62 to 90hrs &Females are apterous. The females remain inside their lac cells and start growing for several weeks. As they grow become globular when they are about to lay eggs they shrink in size providing a space for eggs. At that time the two yellow spots appear at the rear end of the cell. The spot enlarge and become orange coloured. When this happens the females oviposited large number of eggs in the space called ovisac under their tail ends. It is the appropriate time that the twigs (brood lack) are cut from the trees for the purpose of inoculation to new trees. It takes 4 to 8 months to complete its life cycle. Females are the major contributors of lac production.
Terminology used in lac culture 1. Crawlers: The nymphs of lac insect called as crawlers 2. Swarming: Emergence of nymphs from lac incrustation is called as swarming 3. Brood lac: The lac sticks bearing alive mother cells which produce lac larvae are known as brood lac. 4. The stick lac: Sticks carrying ripened lac incrustation cut away from the host tree is termed as stick lac Stick lac is of two types - i. Arilac: It is stick lac cut away from host tree before the swarming and containing some living insects. ii. Phunky lac: It is Stick lac cut after swarming and containing dead females.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 75
Lack Cultivation:- Carried out in forest or semi forest areas. Success of lac cultivation depends upon the management, proper pruning, Harvesting & method of inoculation. 1. Pruning: -Pruning of host plant is done to obtain the succulent branches for feeding lac insects. 2. Inoculation: -The brood lac sticks should be cut in convenient lengths of 15- 30cm & tied to succulent shoot of the host tree longitudinally or laterally. Longitudinal inoculation allows maximum contact between brood & host. The brood used for inoculation should not be left on tree beyond three weeks. Which cause attack of lac insect enemies on host. 3. Harvesting: - For stick lac:-April-May. Brood purpose:-October-November. 4. Preparation of shellac: - Process of manufacturing refined product. 5. Production of crushed lac: - Ripened lac sticks cut from host tree called as stick lac. Arilac- when itis cut before swarming & containing some living insects. Phunki lac- When itis cut after swarming & contains dead females. The stick lac then scraped &crushed coarsely. The crushed lac contain 3-6% wax called lac wax. Seed lac: - Crushed lac is then washed in stone/cement vats/steel barrels in order to separate dead insects & other impurities. Later on they are taken out & spread on the floor for drying. This dried material is called as seed lac. Shellac: - The preparation of Shellac: The process of manufacturing this refined product is completed in three stages- Production of crushed/dust lac, Production of seed lac & the shellac. Crushed lac / Dust lac: It is the lac incrustation scrapped from the stick lac and crushed coarsely. Seed lac: It is the purified and dried lac obtains from crushed lac after removing dead insects and impurities. Shellac: It is the final heat refined marketable product of seed lac. The seed lac is filled in coarse cloth bag & held the bag in front of charcoal fire. Lac starts melting by heat. The fused mass is then squeezed out of bag by twisting bag at both ends.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 76
The filtered lac is collected is earthen vessels containing hot water where it spread into a thin sheet. The shellac can also obtain by dissolving the seed lac in methylated aspirator placing seed lac in autoclave or with the help of modern machine. Harvesting: For obtaining the maximum yield of stick lac it is best to cut the crop in April-May and for brood purpose it should be harvested fully in October- November Lac Crops/ Strains of lac insect Two major strains of lac insects are known in India i.e. Kusumi and Rangeeni Kusumi strain grown on kusum tree while Ranginee strain grown on hosts other than kusum. Rangeeni Strain contributes about 90% of total production so called major crop. Chemical composition of lac- i)Resin - 75%, ii) Dye- 6%, iii)Wax-5-6%, iv) Aluminous matter - 12-13%, v) Mineral matter -3-7%, vi) Water -3%
Pest of Lac insect- White enemy, Black enemy, Chrysopa
Uses of lac Used in preparation of - 1 furniture polish 2 bangles and pens 3 Leather finishes 4 Sealing wax 5 Filling ornaments and jewelry 6 Colour dies 7 Paints 8 Insulation in electrical equipment's 9 Printing
The Indian Institute of Natural Resins and Gums (acronym IINRG), formerly known as the Indian Lac Research Institute, is an autonomous institute, established under the umbrella of Indian Council of Agricultural Research (ICAR) by the Ministry of Agriculture, Government of India for advanced research on lac. Indian Lac Research Institute located at Namkum, Ranchi (Jharkhand).
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 77
NON INSECT-PESTS Rodents Class :Mammalia Order :Rodentia Family :Muridae
Common Name Scientific Name House Rat or Black Rat : Rattusrattus House mouse : Mus musculus Drain Rate or Brown rat : Rattusnorvegicus Field Rats : Bandicotabengalensis Large bandicoot : Bandicotaindica
HOST:- Rats are highly polyphagous, feed on different stored grains and other food material and damage the different crops in field
Nature of Damage: The common rats cause damage to matured palms. Rats remain in the crown of coconut palm and feed on developing nuts. They make hole through the husk and drink sweet liquid and the damage leads 5.7 to 9.4%. Rats’ damage (nibble) the earheads and feed on the developing grains of standing crop in the field. They also carry grains to their burrows. The damage is also equally serious on threshing yards and godowns. It has been noticed that a house rats eats 10 g of food grains/day, while bandicoot takes 15g. The damage to field crop may be from 5 to 25 per cent.
LIFE CYCLE:- Rats produces 6-12 young ones in every three months. The newly born are blind & without hairs. It takes nearly 20 days for the eyes to develop and coat of hairs to form. The rat development is extremely rapid and grows @gm/day feeding only on milk of mother. After 21 days they sneak out with mother and then alone. In about 6 months the rats are mature to breed and may live for 3-5years. The house rat will always prefer cotton, waste paper pieces for bedding to lay young ones. Other rats will lay young ones inside the nest in burrow. Rats are prolific breeder they start breeding at the age of 3 to 4 months and breed throughout the year. A single female can liter as many as 10 young ones at a time with frequency of 10-12 times during a year under favorable conditions. Thus, one pair may give rise to about 800 young ones / year. Life period 3-5 year.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 78
MANAGEMENT PRACTICES:- I) Mechanical Control : 1. Hunting : It consists of engaging of persons who dig out rat burrows and kill the rat with help of trained cats and dogs 2. Trapping: Rats can be caught by traps containing attractive food. 3. Flooding 4. Guarding by rodent proof material 5. Electronic rodent deterrent: In recent year, ultrasonic sounds have been used for repelling rats and mice from godowns. Sound frequency of 20 KHz prevents rats from feeding and reproducing. II) Chemical Control :Poisoning- Chemicals used for the control of rodents are called rodenticides. They include. Zinc phosphide: It most commonly used chronic rodenticide for baiting. It is a black amorphous poisonous powder. It has garlic like odour. It evolves phosphine
(PH3) gas when it comes in contact with hydrochloric acid (HCL) in stomach. It is to be used in the ratio of 2 parts zinc phosphide with 96 parts food grains and 2 parts sweet oil. This kills rat from within 3 hours onwards, requires 2-3 days pre-baiting with plain bait as it may develops bait shyness. Warfarin: This is an anticoagulant type of rodenticide. In the market it is available as Rodafann ‘C’. It causing internal hemorrhage as it stop secretion of prothrombin. In this case prebaiting not required readymade wafarin baits are available. The rats go eating and are bleeding to death. It takes minimum 4 days at a concentration of 0.025%.It is chronic rodenticide. Aluminium phosphide: It is acute poison used for used for fumigation of rat burrows. It is sold as Celphos tablets. It is available in the form of tablets in sealed containers. Two tablets of 0.5% could be dropped in the burrow opening and holes closed by wet mud, the tablets in contact with moisture liberate phosphine gas that kills the rat
Mites- Acarology: - The science which deals with the study of ticks and mites called acarology. Characteristics: - It belongs to phylum- Arthopoda, class-Archinida, order- Acarina and four families such ac., i) Tetranychidae, ii) Tarsonemidae, iii) Eriophyidae, iv) Tenuipalpidae. They have a four pairs of legs, antennae are absent, body is divided into two region- i) Cephalothorax and ii) Abdomen. It is a non-insect pests and polyphagous in nature. These mite has an egg, three nymphal (Protonymph, deutonymph and tritonymph) & adult stage.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 79
Damaging stage is both nymphs and adults. Newly hatched is known as larva that has only 3 pairs of legs. Host Plants: Highly polyphagous, damaging different field crops and horticultural crops. Important species of mites-
1) Two spotted spider mites- Tetranychusurtichae, Tetranychidae
2) Red/carmine spider mites- Tetranychuscinnabarinus, Tetranychidae
3) Sugarcane mites- Oligonychusindicus, Tetranychidae
4) Yellow mite- Polyphagotarsonemus latus,Tetranychidae
5) Wooly mite/Eriophyide mite- Aceria spp. Tetranychidae
Nature of Damage: suck the cell sap, usually colonize the lower surface of the leaves prefers the N-riched young leaves also can use older leaves they spin the webbing and covers the entire plant. Browning of the leaves and heavy leaf drop observed. Infested leaves turn chlorotic, with small transparent lesions. Bright yellow patches develop finally turning dark. Heavy infestation results in to leaf and fruit drop
Some of the species is also act as a vector of plant diseases such as-
Pigeon pea sterility mosaic- Aceriacajani
Sugarcane streak mosaic virus- Aceriasacchari
Wheat streak mosaic virus- Aceriatulipae
Fig mosaic diseases- Aceriaficus
MANAGEMENT PRACTICES:- a) Cultural practices- 1. Avoid monoculture 2. Encourage intercropping 3. Destruction of infested plant 4. Clean cultivation b) Predators - Use of predatory mites c) Chemical control- Chemicals used for the control of mites are called as acaricides. E. g. Dicofol 0.05, fluvalinite0.012% , abametin 0.0025%, flufenoxuron 0.01 etc Spray Wettable sulphur 0.2% or Dicofol 0.03% 0r dusting of 300 mesh sulphur dust @ 25 kg/ha.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 80
Nematodes Nature of damage: - After hatching the juveniles (larvae) enters into the roots and feed within the roots by sucking cell sap. Plant parasitic nematodes are associated with plants. Live in top 20-25 cm layer of soil. They suck the cell sap through root. Before sucking they inject some saliva in cell, the enzymes contained in it predigest the cell contents. Majority of nematodes are root feeders Symptoms of nematode damage: - i) Symptoms are nonspecific & often likely to be confused with those caused by other pathogens or soil factors like bad drainage, lack of nutrition, drought, alkalinity or salinity. ii) Stunting & wilting, leaf curl, leaf & fruit dropping, Premature ripening of fruits, extra branching on plant or root, chlorosis & yellowing of plants, development of root galls, etc. Life History: The females lay the eggs on surface of feeder roots in masses in gelatin matrix. The life cycle is completed within 3-5 weeks depending on climatic conditions. Management Practices: A) Cultural methods: 1) Summer follow and ploughing, 2) Crop rotation with non- host plants, 3) Soil solarization before sowing seed of vegetable crops, 4) Intercropping by sowing the crops like tagetes, sunnhemp, mustard, fenugreek etc., 5) Application of F.Y.M., organic amendments oil cakes like neemcake, caranjkake etc. @ 2 t/ha., 6) Discoiuraging the planting seedlings of vegetables or fruit crops from nematode infested fields. B) Biological control: Use of fungal biopesticidal formulations comprising Trichoderma and paecalomyces. C) Chemical Control: Chemical which kill the nematodes is called as nematicides. E.g. Application of granular insecticides like carbofuran 3G or phorate 10G @ 1 to 2 kg a.i. /ha for vegetables and other seasonal crops and 4 kg a.i./ha for grown-up fruit crops.
Snails & Slugs
What are they? Slugs and snails feed on a variety of plants as well as on decaying plant matter, chewing irregular holes on the leaves of plants. There are around thirty species of slugs in Britain. Slugs and snails move by means of a muscular foot which secretes mucus along which the animal glides. This mucus later dries to form the tail. How do they live? Snails lay approximately 80 round white eggs into holes in the soil. It takes about two years for snails to mature and about approximately one year for slugs to reach maturity. Both slugs and snails need moisture and are most active at night or during cloudy and rainy days. On dry, sunny days snails shut themselves into their shells, sealing the entrance to keep moist during cold weather slugs and snails hibernate in the topsoil. Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 81
Control Eliminate, as far as practicable, anywhere where snails or slugs can hide during the day. Stones, debris, vegetation growing close to the ground, giving dense ground cover make ideal hiding places. Reducing hiding places allows fewer snails and slugs to survive Hand picking slugs and snails can also control them. If you water infested areas of your garden in late afternoon you will encourage slugs and snails to come out. Searching the area at dusk and removing the slugs and snails can be a very effective form of control. Put them in a plastic bag for disposal. Snails and slugs can be trapped under boards or flower pots positioned throughout the garden. Beer-baited traps are effective although their range is confined to only a few feet. The chemical used for soft bodies’ insects (Mollusca e .g Snails & Slugs) are called as molluscicides. Slug pellets Slug pellets containing metaldehyde are a useful form of chemical control.
Birds- Some birds are harmful to crops which causes considerable yield loss. Crow: -The common house crow as well as jungle crow. Managed by destroying eggs & nest during June– Aug. A piece of chapatti dip in 0.3% methyl parathion placed on top of the roof. Parrots: - They cause damage to the fruits. Sparrows: - They common birds. Control by destroying eggs, a piece of chapatti dip in 0.3% methyl parathion placed on top of the roof. Use the sound producing machines or drums.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 82
VERMICOMPOSTING
In general earthworm is divided into two groups, 1) Microdrilli worms (Aquatic) and Megadrilli (Terrestrial). Eisenia foetida is also called as a red worms, tiger worms and manure worms. It is the world most widely used earthworm species. Eudrilus eugeniae is the fastest growing species of earthworm and second most widely used. It is popularly known as Night Crawlers. It is recommended for Vermiculture in Pune and North Kokan in Maharashtra.
Phylum - Annelida Class - Oligochaeta Order - Haplotoxida Sub-order - Enchytraeina, (Eisenia foetida), Lumbricina (Eudrilus eugeniae) Family - Lumlaricidae (Eisenia foetida), Eudirilidae (Eudrilus eugeniae) Species - i) Eisenia foetida (Most widely used) ii) Eudrilus eugeniae iii) Megascolex(Lampito) mauritlii (South Indian Earthworm) iv) Pheritima elongate v) Lumbicu rebellus (European Earthworm)
Morphology of earthworm - Earthworm is a bilaterally symmetrical and body is cylindrical in shape. Segmentation - The earthworm body is divided into similar ring like segments called as metameres or somites. The segments are separated from each other by distinct ring like grooves. Head - Earthworm lacks a distinct head and sense organs (Eyes and tentacles). The first segment at the anterior body is called as buccal cavity or peristomium which bears mouth. Clitellum - Every mature earthworm bears a thick collar or girdle like glandular thickening of body wall called as clitellum. The main function of clitellum is to secrete mucus and egg case or cocoon for eggs. Regionation - Due to the clitellum the body of earthworm is divided into three regions- preclitellar, clitellar & post-clitellar. Setae - Each segment bears setae except peristomium and clitellum. These assist in locomotion. These setae made up of nitrogenous substance called as chitin. Coelom - The body cavity of earthworm is a true coelom which lies between body wall and alimentary canal. Digestive System - Alimentary canal is differentiating into mouth, buccal cavity, pharynx, esophagus, stomach, gizzard, intestine, rectum and anus. Crop is absent. Feeding action - They feeds on organic matter along with soil. Ingested food is lubricated by mucin and protease enzymes. Calciferous glands present in stomach secrete a substance to neutralize the humic acid present in soil. Intestine is the principal site of digestion.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 83
Circulatory system - Earthworm have a closed type of circulatory system which consist of blood vessels and capillaries. Blood contains red pigments such as hemoglobin or erythrocruorin. Excretory System - It contains coiled tubes called nephiridia for excretion. Nephiridia are present in all segments except first three segments. Respiratory System - Respiration takes place by diffusion of gases through a body surface. Nervous System - It consist of central, peripheral and sympathetic nervous system. They contain both sensory and motor neurons. Reproductive system - They are monoecious (A plants or invertebrate animals having both the male and female reproductive organs in the same individual; hermaphrodite.). Two pairs of testis and ovaries are present. They cannot fertilize their own eggs. Cross fertilization takes place by cocoon formation hence fertilization takes place in cocoon. Clitellar glands that form a membranous band around clitellum secrets chitinous substance for cocoon formation. The newly hatched earthworms resemble the adult except for size and absence of clitellum. Sense organs - They don’t have special sense organs. Epidermal receptors are sensitive to touch. Buccal chamber sensitive to taste and smell. They are negatively phototrophic to strong light and positive to weak light. Regeneration - They have a great capacity for regeneration. At the cut surface the wound is first sealed with dense mass of undifferentiated cells called Blastema. Colour - The intensity of colouration may differ from anterior to posterior and dorsal to ventral side. The presence of porphyrin pigments is responsible for colouration.
Vermiculture: - It is the scientific method of breeding & raising earthworms in controlled conditions. Vermicomposting: - It is a method of making compost with the use of earthworms, which generally live in soil, eat bio-mass & excrete it in digested form called vermicomposting. Vermicompost: - The compost formed by the Vermicomposting.
Procedure of Vermicomposting: - Select the place for Vermicomposting. Place should have sufficient shed. Make a thick layer (7-8cm) of stubbles & locally available weeds in suitable size bed. Make second layer of same thickness of partially decomposed FYM. A Vermicompost layer of 1.5-2cm containing earthworm is spread on it. Make 5-6cm thick layer of partially decomposed bio-Agri waste materials is spread at the top. The total height of may be maintained about 0.30-0.45m from ground level. This heap is then covered by jute or gunny bags. Each layer is sprinkled with water. Water should be frequently applied to heap to maintain 30-40% moisture. The temperature of heap should not exceed from 35°c.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Insect Ecology and IPM Including Beneficial Insects 84
Harvesting the earthworms & compost: - Empty the content of worm bean into a plastic sheet where there is strong sunlight or artificial light. Wait 20-30 minutes, and then scrap off the top layer of Vermicompost. The worm will move away from light, so you can scrap more compost off every 20minutes. After several scraping you will find worms in cluster; just pick up the worms & gently return them to the fresh bedding. Advantages: - i) Chemical fertilizers increases the soil pollution, they are not used for second season & harmful to soil microorganisms. Some also get leached with water. ii) Vermicompost also minimizes hazards caused by soil pollution. iii) It increases soil fertility as well as soil productivity. iv) To improve soil structure & texture. v) The vermi-wash is also excellent fertilizer. vi) It gives large amount of NPK to field.
Compiled by Prof. A. S. Mochi & Prof. T. B. Ugale (K. K. Wagh College of Agriculture, Nashik)
Karmaveer Kakasaheb Wagh Education Society’s K. K. Wagh College of Agriculture, Nashik Saraswati Nagar, Panchavati, Nashik-3
AFFLIATED TO MAHATMA PHULE KRISHI VIDYAPEETH, RAHURI (M.S.) LECTURE NOTES ON CROP PESTS STORED GRAIN PESTS AND THEIR MANAGEMENT COURSE NO. : ENT-353 Compiled by Mr. T. B. UGALE Mr. A. S. MOCHI Assistant Professor DEPARTMENT OF AGRICULTURAL ENTOMOLOGY
Exercise No.1
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STUDIES ON POLYPHAGOUS PESTS
Material : Preserve specimens and damaged plant parts. 1. White Grub : Holotrichia serrata F, H. consanguinea Bl. Leucopholis lepidophora Burm. Scarabaeidae : Coleoptera Economic Importance : It is a cosmopoliatan and polyphagous species having been reported from most of the States of the country. Since last 10 to 15 years grub is posing a great threat to the cultivation in some pockets of Maharashtra State. It is in endemic form in some pockets of Ahmednagar, Buldhana, Dhule, Jalgaon, Kolhapur, Osmanabad, Parbhani, Sangli, Satara and Wardha districts. Marks of Identification : Adult : Beetle is stoutly built, reddish brown 22-25 mm in length and head is oblique Eggs : Creamy white, oval/spherical, 2mm diameter. Grub : About 47 mm long, white in colour with dark brow head having power full mandibles and 3 pairs of prominent thoracic legs. Host Plants : White grubs are polyphagous. Larval Hosts : Attack number of crops like sugarcane, groundnut, jowar, maize, paddy, tobacco, vegetables etc. and grasses. Perennial trees like guava, citrus, peach etc. are also reported to be attacked by the grub. Adult Host : The adult beetles feed on leaves of neem, shevaga, ber (Drumstic), tamarind, bel, acacia (Babhul), gulmohor. Nature of Damage : The grubs feed on roots and rootlets of plant and infested plants become yellowish and dried up. The attacked plant can be easily pulled out from the soil. The adults feed on leaves of ber, neem, drumstick. etc. Carry Over : Through the adult beetle. Newly formed beetle remains in quiescent stage in soil and emerges when cloudy weather and light showers prevail in the month of May/June. Life History : The emergence of beetle begins after first pre-monsoon showers (May/June), emergence confined to early evening, after the sunset, mating takes place on neem and babhul trees. Beetles return to soil before sunrise and female start laying the eggs singly in earthen cells at the depth of 7-10 cm. soil. A female lays 50-70 eggs. Incunation period 9-24 days. Grub : Grub moult twice and become full grown in 5-9 months. Pupal stage : Pupation in soil. Pupal stage last for about 14-29 days. Adult : Though adult are formed during November and December they don’t emerge until the first pre-monsoon shower in May or June. The longevity of adult after emergence is 47-97 days. Only one generation in a year. Seasonal Occurrence : The pest is active in Kharif season. Management Practices : 1. Collection of beetles by shaking host trees (neem/babhul/ ber) at night hours and their destruction in kerosinized water. 2. Collection and destruction of grubs from the field at the time of weeding and interculturing. 3. Flooding of the fields. spray the host trees like neem, babhul and ber with 0.1 % carbaryl in monsoon on community basis. The emergence of beetles is observed immediately after the first pre-monsoon showers. (Mau/June) Note : Leaves of treated host trees should not be fed to animals upto 10 days after treatment. 5. Soil application with quinalphos 5G/phorate10G/ carbofuran3G @ 25 kg/ha. at the time of land preparation of application of FYM.
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6. In case L. lepidophorta around kumbhi river in Kolhapur Dist. use rotavator in May, in whilte grub affected area for the destruction of different stages of white grub.
2. Termites or White ants : i) Odontotermes obesus R, ii) Microtermes obesi H. Termitidae : Isoptera Economic Importance : Termites are polyphagous insects, reported from many parts of Maharashtra. The infestation of termites is more in sandy loam soils. They inflict more serious damages in the unirrigated areas. Marks of Identification : These are social insects living in a colony. Polymorphic forms are noticed. A) Reproductive caste : (Winged) : They live in royal chambers. Queen : Develop from fertilized eggs. It is much larger in size and has creamy white abdomen which is marked with transverse dark brown stripes. It lives for 5-10 years and lays thousands of eggs. King : Develop from unfertilized eggs. It is much smaller than queen and slightly bigger than workers. It is secondarily wingsless insect. B) Sterile caste : (Wingless) : Workers : Develop from fertilized eggs. They are whitish yellow. Head wider than reproductive castes. Mandibles are stronger, meant for feeding on. They avoid light and need high humidity for their survival. Soldiers : Develop from unfertilized eggs. They have large head and strongly chitinized sickle shaped mandibles, defend the colony by fighting. (Mandubulate type soldiers). Host plants : Termites are polyphagous feeding on crops like wheat, sugarcane, groundnut, cotton, chillies, brinjal, fruit trees etc. Nature of Damage : Workers of termites feed on the roots and stem parts of the plants. This results in drying of the plants. Other forms do not cause any direct damage to the crop. Life History : Soon after, first monsoon showers, the sexual forms leave their colony for nuptial flight during evening. After a short flight mating takes place, they shed their wings and the queen and king settle down in the soil. The female burrows in the soil, lay eggs and establish new colony. The queen gradually grows in size and start egg laying very rapidly at the rate of one egg per second or 70,000 to 80,000 eggs in 24 hours. It lives for 5 to 10 years. It can live for several years also. There is only one queen in a colony. Incubation period is one week in summer and within 6 months larvae develop to form soldiers or workers. The reproductive castes when produced mature in 1-2 years. Management Practices : 1. Locate termitoria (mounds) and destroy queen by digging out termitoria or fumigating with fumigants like CS2/methyl bromide/CS2 + chloroform mixture @ 250 ml/mound. 2. Termite damage in standing crop can be minimized by application of 5 lits. of lindane 20 EC/ha. into irrigation water or field spreading of 1 lit. of lindane or chlorpyriphos mixed with sand or soil, followed by light irrigation. 3. Keep the crop healthy and vigorous. Shortage or water leading to initial drying of the plant, may lead to termite infestation. Hence, it is very necessary to keep the crop healthy and vigorous. 3. Locust : Species : Locust are those species of grasshoppers, which under certain favourable conditions, multiply, congregate, move together in their nymphal stages as band and the resultant swarms fly to distant areas in dense. Their epidemics occur in all continents. There are nine well recognized species. The following species occur in India. 1. The Bombay locust : Patanga succincta L. 2. The Migratory locust : Locusta migratoria L. 3. The Desert Locust : Schistocerca gregaria.Very common, most destructive. Famity : Acrididae Order : Orthoptera
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1. Bombay Locust : Patanga succincta L. i) The area of distribution : India, Ceylon and Malaya. In India – area extending from Gujarat to Madras and in certain areas upto Bengal. Swarms 1835-45, 1864-66, 1901-1908 resulted in heavy damage to crops. ii) Breeding grounds : Open areas of Western Ghats. iii) No. of broods : 1 in a year (diapause in adult) These hoppers do not congregate to form bands but remain scattered among crops or grasses. 2. Migratory Locust : Locusta migratoria L. i) Distribution : Europe, Africa, East Asia and Australia. Swarms : In India they were observed in 1898 in Madras, and in Banglore 1954. ii) Breeding grounds : Breeds in spring in Pakistan and resultant adults migrate into the desert area of India as individuals and breed during summer in Rajasthan –Gujarat areas of India. Scattered locust may gather in ecologically favourable pockets and lay eggs innumerably i.e. there are several broods in a year. 3. Desert Locust : Schistocerca gregaria The desert locust is a pest of world wide importance as it is known to migrate in swarms from one country to another. i) Distribution : It is an international pest affecting about 60 countries, mainly India, Pakistan, Afganistan, Arebia, Persia, Iraq and Africa. ii) Breeding regions : The pest breeds during the spring season in costal and other areas of West African Countries like Persia where the winter rains bring about the required degree of soil moisture and vegetation. The adults emerging from this breeding stage migrate eastward to Pakistan and India by about the beginning of monsoon. iii) The Phase Theory of Locust : The phase theory was first put forth by Uvarov on the basis of his studies on Locusta in Russia. Previously L. Migratoria and L. danica were recognized as two distinct species as they exhibited marked differences in colour, morphology, physiology and behaviour. Investigations by Uvarov, However, revealed that the L. migratoria and L. danica were the same species which existed in 2 phases. Two forms gregarious and solitary are connected by intermediate from transines. This theory was subsequently confirmed for other species of locust also. Gregarious phase exhibit black colour pattern and same is absent in solitary. Solitory has uniform colour which resembles that of vegetation on which they live. Under laboratory condition the colour of the solitary phase hoppers can be changed into that of gregarious by breeding them under crowded conditions and vice-versa.
Reasons of out break : In breeding regions there are regular showers of rainfall in both the rain fall belts, which brings about the required degree of soil moisture and vegetation. However, strong winds do not scatter the swarms.
Nature of Damage : Locusts are voracious feeders, each adult, consuming its own weight of vegetation daily. It is estimated that 1 sq. km. settled swarm contain about 3000 quintales of locust. An average swarm is 10 sq.km.. Biggest 300 sq. Kilometer swarm is on record. Similarly, hoppers eat 6-8 times more than their own weight. It has been assessed that in India during 1926-31 plauge, the damage caused to crops, fodder etc., was about 10 crores of rupees and consequential loss to premature death of cattle and other livestock was in calculable.
Methods of Locust Control : The chief aim of locust control is to destroy the locust in all its stages. 1. Destruction of eggs : Locating the egg laid areas is almost importance, then trench them around so as to entrap the young hoppers as they move out after hatching. Even actual destruction of eggs on organized scale may be carried out by ploughing, harrowing and hand digging. 4
2. Hopper Control : The mechanical methods include entrapping the making hopper bands in 2’ x 2’ trenches and burying. The chemical method include use of poison baits and dusting of insecticides. Dusing of 2 % methyl parathion dust against hoppers @ @5 to 30 kg/ha. has been found to bring a complete control of these pests. 3. Control of adults or winged locust swarms : 2% methyl parathion may be carried out to achieve better control when swarms are resting on bare ground at night or in early morning can be beaten or swept up and destroyed. If they are resting on bushes or hedges, they can be easily burnt with help of flame throwers. When flying locust are about to descend in large swarms in cultivation aeras, best way to tackle them is to prevent them by creating a cloud of smoke or by burning refuse etc. Spraying with neem kernel suspension as a deterent to the crop, has also been tried with success. Recently with the introduction ‘aerial application’ of insecticide the control of locust swarms has become easier. The advantage associated with aerial spraying are : i) Vast areas can be treated in relatively short time. ii) The swarm in flight can also be treated. iii) When swarms settle down in a particular area that area can be quickly covered by aerial application. iv) The moment of swarm can be watch with ease. Locust control organizations, In India: Locust warning organization of the Govt. of India was established from April 1939. In 1942 a coordinated Anti locust scheme was put interaction. In the World : United Nations Special Fund Desert locust Project which was sponsored by the F.A.O. in 1960. This is being subscribed by several countries including India. Its purpose is to develop more effective and less expensive control of the desert locust.
4. Armyworm : Mythimna separata Walk. Noctuidae : Lepidoptera Economic Importance : It is one of the cosmopolitan and polyphagous pests. It is sporadic in occurrence but sometimes breaks out in epidemic form especially when there is a good start of rains followed by a long dry spell. Complete failure of crops is also common in case of heavy attack.
Marks of Identification : Moth-medium sized, forewings grayish brown with prominent spots at the anterior margin. Hindwings pale white with dark borders. Caterpillar dull greenish, 4 cm in length, broad light colourted strips on the lateral side of the body.
Host Plants : Polyphagous attacking wide range of cereals and pulses.
Nature of Damage : The pest is nocturnal in habit. Caterpillars generally hide during day time in the soil or in leaf whorls. The larvae feed during night on the leaves from margin and in case of severe infestation defoliate the plants completely. On exhausting food from one field the caterpillars march like an army to neighbouring fields and hence the name army worm.
Life History : Eggs-are laid on central leaves. Incubatioon period- about a week. Larva – larva period 3- 4 weeks. Pupa – pupation in soil. Pupal period 8 to 10 days. life cycle – completed in about 5-6 weeks. Generations : 5 generations every year. Carry over – Pest usually hibernates in pupal stage in soil. Seasonal occurrence : The pest is active from June to November
Management Practices : 1. Ploughing the field after harvest of the crop and burning plant debris helps in destroying the hibernating pupae. 2. Mechanical collection of larvae and their destruction. 3. Dusting methyl parathion 2D @ 20 kg/ha as soon as incidence is noticed. 4. Spraying with 0.05% endosulfan / 0.2% carbaryl. Note : Dusting or spraying should be carried out during evening. Practical Guidelines : Draw figures of caterpillar, moth and damaged leaves on plant. 5
5. Cutworm : Agrotis ipsilon Rott. Noctuidae : Lepidoptera Economic Importance : Cosmopolitan pest, reported to occur throughout the country. It is serious in low lying areas which remain water logged for considerable time during the year. It causes severe damage in seedling stage. The damage to the crop varies from 12-35 % Marks of Identification : Moth : Medium sized, stout with grayish brown wavy lines and spots on fore wings. The moths are active at dust and are attracted by light. Caterpillar: 4-5 cm long, dirty black in colour and have habit of coiling at slightest touch. Host Plants : Potato, pulses, barley, oat, tobacco, peas, gram, cotton, tomato, Lucerne, chillies, brinjal and other vegetables.
Nature of Damage : The caterpillars hide during the day in cracks and crevices in soil or in debris around the plants and feed on tender leaves during night by cutting seedling near ground level. The destruction is much more than actual feeding.
Life History : Eggs : 300-350 in clusters laid on ventral leaf surface or moist soil. I.P. : 4-5 days. Larva : L.P. 3-5 weeks. Pupa : Pupation in soil in earthen cacoons P.P.11-18 days. Life Cycle : Completed in 5-9 weeks. S.O. : It is a cool climate pest, active from October.
Management Practices : 1. Heaps of green grasses may be kept at suitable interval in infested field during evening and collected next day early in the morning along with caterpillars and destroy. 2. Clean cultivation and mechanical destruction of caterpillars also help in reducing pest infestation. 3. 5% carbaryl poison bait @ 25-60 kg/ha controls the pest effectively. (1kg carbaryl 50 WP + 10 kg wheat bran + 1 kg jaggery and sufficient water). 4. Apply lindane dust @ 125 kg/ha. or fenvalerate 2%@ 50 kg/ha or chlorpyriphos 20 EC 0.05% before planting of potato crop.
6. Tobacco leaf eating caterpillar (Spodoptera) : Spodoptera litura F. Noctuidae : Lepidoptera Economic Importance : The pest is cosmopolitan and polyphagous infesting various crops in the world.
Marks of Identification : Adults : Moths are medium sized stout with forewings grey to dark brown in colour with wavy marking. Hindwings are whitish . Larva : Caterpillar are pale greenish brown and smooth, with dark marking and prothoracic plate.
Host Plants : Tobacco, peas, brinjal, banana etc.
Nature of Damage : The caterpillars, when young, feed gregariously on leaves and juicy stems and become isolated at later stage of growth.
Life History : Eggs : Laid in masses, covered with brown hairs on tender leaves I.P. : 4-5 days. Larva : Darkish in appearance. Initially, on hatching feed gregariously on soft tissue during night and become isolated when full grown. L.P. : 14-21 days. Pupa : Pupation in earthen cocoons P.P. : 9- 14 days. Life cycle : completed in 30-60 days. Management Practices : 1. Collection of eggs masses and caterpillars and their destruction. 2. Ploughing after harvest of the crop to destroy the pupa. 3. At the early stage of infestation, dusting with 10% carbaryl @ 20-25 kg/ha. controls the pest satisfactory. 4. Spraying of SINPV @ 250 LE.
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5. Use of sex pheromone traps with spodolure. 7. American bollworm (Helicoverpa) : Helicoverpa armigera H. Noctuidae : Lepidoptera Economic Importance : It assumes epidemic proportion under favourable climatic conditions. The pest is common in localized areas of Maharashtra. Marks of Identification : Moths stout, light yellowish to brown, forewings pale brownish with some black dots and hindwings lighter with smoky borders. Caterpillars greenish with dark broken grey lines along the sides of the body.
Host Plants : Infesting cotton, gram, tur, peas, tomato, tobacco, safflower, sunflower, jowar etc.
Nature of Damage : The caterpillars feed on tender foliage, squares, flowers and bolls/pods/fruits. While feeding, caterpillars insert the anterior half portion of their body inside the bolls. They feed on seeds and cause substantial damage. Life History : Eggs – female lays 200 eggs singly on tender parts of the plant. Incubation period 6-7 days. Larva –larval period 2 weeks. Life cycle completed in 5-6 weeks. Several generations in a year.
Seasonal Occurrence : The pest is active from November to March.
Management Practices : 1. Ploughing the field after harvest of the crop would destroy the pupae, nearly by 70%. 2. Hand picking of caterpillars in the initial stage of attack. 3. NPV of Helicoverpa armigera @ 250 LE/ha (Prepare the stock solution of 250 LE and add it in 500 litres of water and spray for 1 ha.) 4. Spraying with 5 % NSKE. 5. Spraying the crop with 0.05% endosulfan/ formothion/ quinalphos / phosalone Or dusting with endosulfan 4D/ phenthoate 2D / quinalphos 1.5 D / phosalone 4D / malathion 5D / methyl parathion 2D @ 20 kg/ha as soon as 5 % pods/bolls / fruits are damaged, or 2 larvae per metre row are noticed. (ETL.) 6. Use of pheromone traps (Helilure) @ 5 /ha.
8. Mites : Major species : 1. Two spotted spider mite : Tetranychus urticae, Tetranychidae : Aacarina 2.. Red or carmine spider mite: Tetranychus cinnabarinus, Tetranychidae : Aacarina 3. Sugarcane mite : Oligonychus indicus H., Tetranychidae : Aacarina 4. Yellow mite : Polyphagotarsonemus latus B. Tarsonemidae : Aacarina 5. Woolly mite / Eriophyid mite : Aceria spp. Eriophyidae : Acarina.
Economic Importance : Mites are the most common non-insect pests associated to the diverse group of crops. Generally their incidence is more severe during warm climate and also on crops grown in green houses. Numerous species of different genera of mites are distributed throughout the world.
Marks of Identification : The morphological characters differ according to the species. In general, they are very small orthropods (1 to 3 mm long) the newly emerged larva is six legged, however, the nymphs (protonymphs, deutonymph) and adults have always eight legs. Exception to this is Aceria spp. (gall mites, eriophyid mites etc.) having only four legs and are elongated worm like very minute in size. The body of mites is divisible in two regions – cephalothorax and abdomen and the colour varies according to species.
Host Plants : Highly polyphagous, damaging different field crops and horticultural crops. 7
Nature of Damage : Both nymphs and adults suck the cell sap from plant parts. Infested leaves turn chlorotic (yellow patches) and development of fine webbing and dust particles or well as brownish patches. Heavily infested leaves and fruits may drop down. Sometimes the leaves turn reddish colour and curling of the leaves is noticed.
Life History : Females lays about 50 to 80 eggs on under surface of leaves. Incubation period varies according to the species and climatic condition. Generally it ranges from 3 to 7 days. Nymphal period is 1 to 2 weeks. Adult longevity is 1 – 2 weeks. Like cycle is completed in 9 to 15 days.
Seasonal Occurrence : The pest is more active during summer months. Management Practices : A) Cultural practices : 1. Avoid monoculture practice. 2. Encourage intercropping with non host crops. 3. Destruction of mite infested plant parts. 4. Clean cultivation. B) Chemical Control : Spraying of wettable sulphur 0.2 % or dicofol 0.03% or dusting of 300 mesh sulphur dust @ 25 kg/ha.
9. Rodents (Rats) : Muridae : Rodentia : Mammalia Economic Importance : Rats are of great economic importance because of their variable role in problems of human food and health.
Marks of Identification : 1. House Rat or Black Rat : Rattus rattus Linn. Weight is between 120-125 g. length 35-38 cm. 2. House mouse : Mus musculus Linn. Weight is between 23-26 g. length 15-20 cm. 3. Drain Rate or Brown rat : Rattus norvegicus Birk. Weight is between 142-146 g. length 35-41 cm. 4. Field Rats : Bandicota bengalensis Gray. Weight is between 234-237 g. length 36-41 cm. 5. Large bandicoot : Bandicota indica Bech. Weight is between 370-414 g. length 38-45 cm.
Host Plants : Rats are highly polyphagous, feed on different stored grains and other food material and damages the different crops in field.
Nature of Damage : Rats damage (nibble) the earheads and feed on the developing grains of standing crop in the field. They also carry grains to their burrows. The damage is also equally serious on threshing yards and godowns. It has been noticed that a house rats eats 10 g of food grains/day, while bandicoot takes 15g. The damage to field crop may be from 5 to 25 per cent.
Life History : Rats are prolific breeders, they start breeding at the age of 3 to 4 months and breed throughout the year. A single female can liter as many as 10 young ones at a time with frequency of 10-12 times during a year under favourable conditions. Thus, one pair may give rise to about 800 young ones / year. Life period 3-5 years. Management Practices : I) Mechanical Control : 1. Hunting : It consists of engaging parties of persons who digout rat burrows and kill the rats. 2. Trapping : Trapping the rags and later disposing them off is one of the oldest methods of rat control. Good results of trapping the rats depend upon use of sufficient number of traps and their proper placement. They should be placed at right angle along walls or between objects. 3. Flooding : With powerful water supply. The flooding of burrows used to force the rats out during day time when they can be killed mechanically. 4. Guarding by rodent proof material:Specifically in fruit crops like coconut,etc.
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5. Electronic rodent deterrent : In recent year, ultrasonic sounds have been used for repelling rats and mice from godown. Sound frequency of 20 Khz prevent rats from feeding and reproducing. II) Biological Control : Cats, dogs, mongoose, snakes, birds, etc. play an important role in checking the build up of rat population. III) Chemical Control : Chemicals used for the control of rodents are called rodenticides. They include. 1. Zinc phosphide : It is dull, black coloured pulvarised powder. It is soluble in water. After reaching in the stomach it reacts with acidic juices and produce phosphine (PH3) gas which is absorbed in the body and because of its toxicity rat is killed. Zinc phosphide poison bait : (2% bait by wt.) The bait should be prepared by mixing 1 part zinc phosphide 80 % with 49 parts crushed grains and little quantity of any edible oil (sweet oil). A spoonful of bait wrapped in a paper packet should be inserted deep in every live burrow with the help of bamboo stick and the opening of the burrow should be closed with grass and mud. 1 kg of bat is sufficient for treating 200 burrows. The bait when consumed, the hydrochloric acid (HCL) present in the gastric juice reacts with it and phosphine gas is evolved which is rapidly absorbed in the system and cause death. It is a single dose poison or Acute poison. Single dose sufficient to kill the rat. With continuous use of this poison the rats develop bat shyness and hence prebaiting (without poison) is required. 2. Warfarin : This is an anticoagulant type of rodenticide. In the market it is available as Rodafann ‘C’. After entering into the body of rats it stops secretion of prothombin which is necessary for clotting of blood. Secondly, capillaries are damaged and lead to bleeding. In the absence of prothombin bleeding continues and rat dies slowly. The advantage is that rats do not get suspicious of the food, do not induce bait shyness and hence no prebaiting is required. It is chronic poison, kill the rats when taken in several doses. The baid should be prepared by mixing 1 part 0.5% warfarin with 19 parts of roasted and crushed gains of bajra or wheat and little quantity of edible oil. Ready to use baits are available. 3. Bromadiolone bait (Roban / Moosh-moosh) : Ready to use bait. Anticoagulant rodenticide. Single dose is sufficient to kill the rat. Death occurs slowly in 4-5 days. Do not develop bait shyness and hence, pre-baiting is not required. The bait is prepared by mixing 1 part 0.005% Bromadiolone 0.25% formulation with 40 parts of wheat flour/crushed wheat (carrier). Ready to use bromadiolone cakes are also available. 4. Aluminium phosphide : It is used for fumigation of rat burrows. It is sold as Celphos tablets. A ½ tablets of 3 g could be droopped in the burrow opening and holes closed by wet earh. The tablets in contact with moisture, liberates phosphine gas that kills the rats in burrows. It is very hazardous and highly inflammable and hence should be used carefully.
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Exercise No. 2 STUDIES ON PESTS OF RICE
Material : Preserved specimens and affected plant parts. The common pests infesting rice crop in Maharashtra state are as given below. Major Pests : 1. Stem Borers : a) Yellow Stem Borer : Scirpophaga incertulas Walk. Pyralidae : Lepidoptera Economic Importance : It is one of the major pests of paddy. It is a specific pest of paddy and has world wide distribution. It is very serious in areas where more than one crops of paddy are taken in a year. Marks of Identification : Moths : Medium sized, 10-15 mm in length, forewings yellowish, hindwings whitish, black dot on each of the forewings and tuft of yellowish hairs on anal segments in female moth. Caterpillar – yellowiosh, 20 mm, yellowish brown head. Host Plants : Rice only. Nature of Damage : On hatching from the egg, the larva bores inside the stem of the paddy plant. As a result of feeding, the central shoot is killed causing “dead heart”. The attack in the later stage results in yellowing of leaves and white earheads locally known as “Palinj. Life History : Eggs-100-200 eggs are laid on upper surface of leaves near the tips. Incubation period 6- 7 days. Larva-larval period 4-5 weeks (6 larval instars), before pupation larva construct an emergence hole on stem which is always located above the water level in fields. Pupa : Pupation in stem. Pupal period 8-10 days. Adult – adult longevity 5-7 days. Life cycle-completed in 2 months. 3 to 5 generations in a year. Carryover : The pest hibernate in larval or pupal stage in the stubbles during winter season. Seasonal Occurrence : Cold weather with high humidity and low temperature has been found conducive for the multiplication of the pest. b) Stripped Stem Borer : Chilo partellus S. Pyralidae : Lepidoptera Marks of Identification : Moths : Medium, 10 mm, forewings yellowish grey with small black spots at apical portion, hindwings are dirty white. Caterpillars : dirty white with brownish markings, 20- 25 mm in length Host Plants : Rice, paddy, jowar, maize, sugarcane, some hill millets and wild grasses. Nature of Damage : Caterpillars initially feed on leaves and later bore inside the stem producing dead hearts or empty earheads depending upon the stage of the crop. Life History : Eggs- average eggs laid by a female 200 on leaves, incubation period 6 days. Larva – larval period 15-26 days (5 moults). Pupa-pupation in stem. Pupal period 3-5 days. Life cycle – completed in 6-7 weeks. Carryover : Pest hibernate as larva in stubbles in off season. Seasonal Occurrence : The pest is active from July to November Management Practices of Stem Borer Complex : I) Cultural and Mechanical Measures : 1. Avoid late transplanting of the crop. 2. Grow high yielding midlate varieties like Ratna, EP-4-14, I.R.20, IET-3116, IET-3127, IET-9691 and IET-3093. 3. Remove affected tillers and destroy them. 4. Clipping of leaf tips at the time of transplanting to destroy the egg masses. 5. Plough the field immediately after harvest and destroy the stubbles. 6 Conservation of frogs to keep down the incidence of stem borer, army worm, crabs etc. II) Chemical Control :
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1. Nursery Treatment : Application of phorate 10 G @ 10 kg or quinalphos 5 G @ 15 kg or carbofuran 3 G @ 16.5 kg/ha in the soil under saturated moisture conditions. 15 days after sowing. If granular application is not possible due to inadequate soil moisture (sloppy or light type of soil) then spray with fenitrothion 0.08% or endosulfan 0.06 % or quinalphos 0.08% or phenthoate 0.08% when 1 moth or 1 egg mass/ sq.m. is noticed. 2. Dipping of Seeding Roots : Dip seedling roots for 12 hrs. in the solution prepared by mixing chlorpyriphos 20 EC, 500 ml. in 500 litres of water (0.02% solution). For this treatment the bed should be prepared by spreading plastic sheet and making ridges on all four sides for preparing the solution. 3. Field Application : When 5% dead hearts appear in the field or average 1 egg mass / sq.m., apply granules in the soil as given under nursery treatment. At the time of application, the field should have saturated moisture condition or maximum of 7-10 cm. of water level. Do not let in or drain out water for 4 days after application, Or spray the crop with insecticides given under nursery treatment or spraying of Bt @ 1 kg/ha. when 5% affected tillers sq.m. or 1 eggs mass/ sq. m. or 1 moth/sq.m. is noticed. III) Biological Control : Release of laboratory based parasitoids, Trichogramma japonicum 4-5 times at weekly intervals @ 50,000/- parasitoids /ha on noticing stem borer moth activity. Practical Guideline : Draw figures of adult stages of yellow and stripped stem borer.
2. Rice gall midge or gall fly : Orseolia oryzae W.M. Cecidomyidae : Diptera Economic Importance : This pest is distributed throughout India. It has been found to be endemic in Bhandara, Chandrapur and Ratnagiri districts of Maharashtra State. The loss in yield in heavily infested crop may be to the extent of 50 per cent. Marks of Identification : Adult fly-small, reddish brown, mosquito like having long slender legs, body length 4-5 mm. Maggot – pinkish, 2.5 - 3.00 mm in length. Host Plants : Wild rice and grasses like Panicum spp., Cynodon dactylon, Ischaeum cillare, Eleusine indica. Nature of Damage : The tiny maggot hatching out from the eggs creeps down between the leaf sheaths till it reaches the apical point of the central shoot or tillers as the case may be and then it enters the tissues and destroy the growing point. Due to the feeding normal growth of the plant stops and a small gall is produced. This gall gradually elongates and a long hollow silvery shoot emerges in place of normal stem bearing the earhead. The affected plants induces tillering but by the time, flies may emerge in successive generation and again attack the tillers and in case of severe infestation large percentage of plants yield no grains at all. The infestation is highest in tillering stage. The infested tillers do not bears ears. Life History : Egg – average eggs laid by a female 100 on leaves singly or in clusters. Incubation period 3-5 days. Larva- larval period – 10 days. Pupa – pupation in galls or within the silver shoot. Pupal period 3-5 days. Life cycle : It is completed in 2-3 weeks and 5-8 generations in a year. Carry Over : The pest probably overwinters in the larval stage in stubbles. Seasonal Occurrence : Cloudy skies and drizzling rains are conducive to fast build up of pest. The favourable conditions for fly development is 26 to 30°C temperature and 82 - 86 % humidity. Heavy rains and low humidity cause high mortality. Management Practices : A) Cultural and Mechanical Measures : 1. Destroy all wild grasses and alternate hosts in and around the rice fields to prevent the infestation of this pest. 2. Grow resistant varieties viz., IET 7918, IET 6080, IET 7008, Pratap, Kunti, Suraksha, Vikram and Phalguna.
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3. Removal of affected tillers showing silver shoots and their destruction will keep the pest under check.. B) Chemical Control : 1. Nursery Treatment : Give nursery treatment as stated under rice stem borer, when 1 silver shoot/sq.m. is noticed. 2. Field Application : When 1 silver shoot or gall/sq.m. in endemic area or 5% silver shoots/sq.m. in non-endemic area, apply phorate 10G @ 10 kg or quinalphos 5G @ 15 kg in soil control the pest effectively. Note : Granules should be applied carefully and should not be handled by persons having wounds on feet or hands. Practical Guideline : Draw the figures of adult fly and plant showing silver shoot.
3. Rice Jassids (Green Leaf Hoppers) : Nephotettix nigropictus Stal. Nephotettix virescens Dist. Cicadellidae : Hemiptera. Economic Importance : In the recent years, this pest appears in endemic forms in some part of Maharashtra. In addition to direct feeding damage, they are vectors of rike virus diseases and have almost the same overall economic significance as stem borers. Marks of Identification : Adult greenish, wedge shaped, 4-5 mm in length, black spot on each forewing, Nymphs smaller, wingless and greenish. Host Plants : Rice, wheat, barley and lemon grass. Nature of Damage : Both nymphs and adults suck cell sap from the leaves. As a result the leaves turn yellowish and start drying from tip to downwards. Some species are known to be the vectors of virus diseases. The green leaf hoppers. N. nigropictus are reported to transmit ‘rice transitory yellowing’ and ‘rice yellow dwarf’. Tungro virus disease transmitted by N. virescens is the most serious. Life History : Eggs – about 25 per female within leaf tissues. Incubation period – 4-5 days. Nymph - nymphal period 10-15 days (five moults). Adult longevity 17-22 days in summer and 30-50 days in winter. Life cycle : Completed in about 5 weeks. Generations : Six overlapping generations in a season and several in a year. Carry Over : Over wintering in adult stage, through alternate host plants. Seasonal Occurrence : Pest is active during July-Sept. The abundance of the pest has been attributed to high temperature, low rainfall and abundant sunshine. Generally fields receiving large amounts of nitrogenous fertilizers are mostly infested. The pest population decreases after heavy rain. Incidence is more in ill drained fields. Management Practices : Spray with dimethoate 0.05% or fenitrothion 0.05% or monocrotophos 0.05% or malathion 0.1% or phenthoate 0.05% or dusting carbaryl 10 D @ 20 kg/ha when 1-2 jassids / sq. m. in nursery and 5-10 or more jassids / hill in the field. Note : Dusting should be undertaken in the evening or early in the morning when there is no wind. Practical Guideline : Draw figures of adult stages of this pest.
4. Brown Plant Hoppers : Nilparvata lugens Stal. Delphacidae : Hemiptera Economic Importance : Most destructive pest. It has become serious on high yielding varieties of paddy in many states. Marks of Identification : Nymphs and adults are brown to brownish black, adults 4.5 mm in length. Two types of adults are noticed - 1. Brachypterous – wings are not fully developed. 2. Macropterous – Wings development is complete. Host Plants : paddy, sugarcane and some grasses. Nature of Damage : Both nymphs and adults suck the cell sap from stem and leaves. As a result, the leaves become yellow, dry up and the whole plant dies after a few days. They are normally confined to the basal portion of rice plant. When the population is large, the crop dries up in
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patches and this stage is called ‘hopper burn’. They also transmit grassy stunt virus disease of paddy. Very high infestation causes lodging of the crop. Life History : Eggs about 300 – 350 per female in leaf tissues on either side of midrib and the leaf sheath. Incubation period – 6-12 days. Nymph-nymphal period 15 days, 4 to 5 moults. Adult- lives for 10-20 days in summer and 30-50 days in atumn. Life Cycle : Several generations in a year. Carry Over : It overwinters either as eggs or fifth in star nymphs through alternate host plants. Seasonal Occurance : High nitrogen application, high humidity, optimum temperatures increases the population rapidly. Management Practices : 1. Grow BPH resistant/tolerant varieties viz.,IET-7575, IET-7568, IET-7943 and IET-8115. 2. Spray the crop with insecticides given under the leaf hopper when 5-10 hoppers/hill are noticed. Note : Insecticide should reach lower portion of the plant. Practical Guideline : Draw the figures of adult and nymphal stages of this pest. 5. Swarming Caterpillar & Army Worm: Spodoptera mauritia B. Mythimna separata; Noctuidae : Lepidoptera. (Refer the polyphagous pests, Page No. ). Minor Pests : 6. Paddy Blue Beetle : Leptisa pygmaea B.; Chrysomelidae : Coleoptera. 7. Rice Hispa : Dicladispa armigera Oliv.; Chrysomelidae : Coleoptera. 8. Rice Case Worm : Nymphula depunctalis G. ; Pyralidae : Lepidoptera. 9. Paddy Grass Hopper : Hieroglyphus banian Fb.; Acridiidae : Orthoptera 10. Paddy Leaf Roller or Folder : Cnaphalocrosis medinalis G.; Pyralidae: Lepidoptera. 11. Rice Skipper : Pelopidas mathias Fab.; Hesperiidae : Lepidoptera 12. Rice Earhead Bug or Gundhi Bug : Leptocorisa spp.; Coreidae : Hemiptera. 13. Rice Butterfly (Rice Horned Caterpillar) : Melanitis ismene C. Satyridae : Lepidoptera. 14. Land Crabs : Paratelphus spp. 15. Snail and Slugs : Snail-Helix spp. Slug-Limax spp.; Gastropoda : Mollusca.
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Exercise No. 3 STUDIES ON PESTS OF SORGHUM (JOWAR)
Material : Preserved specimens and affected plant parts. Sorghum is attacked by about 150 pests. The common pests are given below. Major Pests : 1. Jowar Shoot Fly (Stem Fly) : Atherigona soccata Rond. Anthomyidae : Diptera. Economic Importance : It is one of the serious pests of sorghum in India. The pest attacks the crop only in early stage of growth and infestation goes up to 80%. The high yielding hybrids are more susceptible to the attack of this fly. The total loss in yield in sometimes as high as 60%. The pest is very serious on kharif and rabi crops in Maharashtra State. Marks of Identification : Adult fly – dark grey, like the common house fly but much smaller in size, 6 to 4 dark spots on abdominal segments of female and male respectively (arranged in rows of two). Maggot-legless, tapering towards head, pale yellow, small (10-12 mm in length). Host Plants : Jowar and grasses like Andropogan sorghum, Cynodon dactylon and Panicum spp., maize, wheat, some millets. Nature of Damage : Maggots on hatching from the eggs bore into the central shoots of seedlings and kill the growing point, producing “dead hearts”. They feed on the decaying core of the shoots. Subsequently on death of central shoot, plant gives out tillers and plant gets bushy appearance. Life History : Eggs – average 40 eggs are laid by a female singly on lower surface of leaves and tender stem. Incubation period 2-3 days. Larva – larval period 10-12 days (4 larval instars) pupa- pupation in stem. Pupal period-about a week. Adult longevity -12-14 days. Life cycle – completed in 2-3 weeks. Several generations in a year. Carry over- The pest over winters in adult stage on grasses. Seasonal Occurrence : The insect attacks the seedlings and late sown crops are attacked badly. The attack is severe during July to October. Cloudy weather favours multiplication of the insect. In rabi, early sown crop suffers more and hence, sowing should be delayed possibly. Management Practices : 1. Sow the kharif crop as early as possible i.e. immediately after the onset of rains or within 15 days after receiving of rains. Increase the seed rate to make up the loss. 2. Use the seeds treated with carbofuran 50 SP @ 5% a.i. (100 g/kg) by wt. of seed (Gum arabic as sticker) or carbosulfan 25 STD (200 g/kg of seed) OR 3% carbofuran granuals @ 5 kgs/50 kgs of seed by using slurry of wheat flour as sticker. OR 3. Application of phorate 10G @ 10 kg/ha in soil at sowing OR 4. Spray the crop with 0.05% endosulfan as soon as 10% seedlings are infested or 1 egg /10 seedlings are noticed. 5. Removal and destruction of affected shoots alongwith the larvae. 6 Use resistant (Maldandi 35-1) or less susceptible varieties like R.S.V.9 R (Swati), S.P.V.86. Practical Guideline : Draw figures of maggot, fly and plant showing dead hearts. 2. Jowar Stem Borer : Chilo partellus S. Pyralidae : Lepidoptera. Economic Importance : It is one of the major pests of jowar and has a wide distribution. The infestation is noticed till harvest and the grown up plants when damaged loose their vigour and putforth weak ears. The infestation is more pronounced on rabi and hot weather crops. Marks of Identification : Moths-medium sized, straw coloured, yellowish grey forewings. The hindwings are whitish. Caterpillar-dirty white, brown head, many dark spots on the body, 12-20 min in length. Host Plants : Although principle hosts are jowar and maize, it has also been recorded on sugarcane, rabi and certain grasses. 14
Nature of Damage : On hatching from the eggs, the larvae initially feed on tender leaf whorls causing series of holes in the leaf lamina and later bore into the stems, feed on the central shoots causing their death, commonly known as “dead hearts”. Life History : Eggs-about 300 eggs are laid, on leaves in clusters, incubation period-about 6 days. larval period : 3-4 weeks. Pupa : pupation in stem. Pupal period 7-10 days. Before pupation larva prepare a hole on stem at ground level for the moth to escape/come out. Adult : Adult longevity 2-4 days. Life cycle : completed in 6-7 weeks. About 4-5 generations are completed in a year. Carry Over : The pest hibernates in the larval stage in stubbles. Seasonal occurrence : The pest is generally active from July to November. The infestation is more on rabi and summer crops. Management Practices : Preventive and curative measures. Preventive : 1. Collection and destruction of stubbles after the harvest of crop to kill hibernating larvae. 2. Increase the seed rate to compensate the loss. 3. Follow proper crop rotation (with non host crop) 4. Use of light traps. Curative : 5. Removal and destruction of affected shoots alongwith the larvae. 6. Spraying with 0.05% endosulfan or 0.2% carbaryl Or whorl application of endosulfan 4G @ 10 kg/ha, when 10% plants are infested. Practical Guideline : Draw figures of caterpillar, moth and plant showing dead heart. 3. Aphids: i)Rhophalosiphum maidis F. ii) Aphis sacchari Z.; Aphididae: Hemiptera. 4. Delphacids : Peregrinus maidis A.; Delphacidae : Hemiptera Economic Importance : These are the most important sucking pests of jowar. The infestation is usually high on rabi crop. The yield is adversely affected and the fodder quality also deteriorates. Marks of Identification : Aphids : Adults-minute, soft bodied, oblong, light green or pale yellow. Cornicles are characterized by the presence of 2 tube like structures on the dorsal side of abdomen. Aphids are generally wingless but winged forms are often noticed usually in the beginning and towards end of season for migration to other crops. Nymphs : Smaller and greenish. Aphids are found in large numbers on lower surface of leaves and leaf whorls and do not move unless disturbed. Delphacids : Adults : Wedge shaped, pale yellow, walk diagonally. Nymphs –like adults but wingless. Delphacids found mostly in the whorl of the plants. Host Plants : Jowar, bajra, other cereals and sugarcane. Nature of Damage : Both Nymphs and adults suck the sap from plant especially from the leaves. As a result the leaves turn yellow and in case of heavy infestation the plants remain stunted. Their injury causes oozing of sap which crystalises on evaporation forming sugary material called “Chikta” or “Sugary disease”. Due to sugary material oozing out of the plant and honey due excreted by the insects, the sooty mould develops and the leaves turn blackish. The yield is adversely affected and the fodder quality also deteriorates. Life History: Aphids- Only females are noticed in Maharashtra. Reproduction parthenogetically, on an average each female produce about 42 young ones within period of 5 days. Nymphs moults 4 times in a period of 5 days. A generation is completed in about 2 weeks. Delphacids : Eggs-about 150 eggs are laid in leaf tissues, incubation period -7-8 days. Nymphs : nymphal period 15-19 days (moult 5 times). Life cycle completed in about a month’s time. Management Practices : Spraying with dimethoate / quinalphos at 0.03% or formothion/ monocrotophos/ methyl demeton at 0.02% or dusting the crop with endosulfan 4D / quinalphos 1.5D @ 20 kg/ha. Spraying is more effective than dusting. Practical Guideline : Draw figures of leaf showing aphid colonies and a typical aphid with cornicles. 15
5. Army Worms : Mythimna separata Walk. Noctuidae : Lepidoptea. (Already described under Polyphagous Pests, Page No. ). 6. Midge Fly : Contarinia sorghicola coq.; Cecidomyidae ; Diptera Economic Importance : The insect has a world wide distribution and is considered to be one of the important pests of sorghum. The grain loss varies from 20-50%. The severity of infestation has significant effect of overall production of gratin. Marks of Identification : Adult fly– very small, bright red, 2mm in length, wings transparent, slightly dusky, female posses fairly long ovipositor. Maggot-small, dark orange reddish, 2 mm long. Host Plants : Besides, jowar the pest is reported to feed on several grasses such as sudan grass, Johnson grass, Pankanis etc. Nature of Damage : Maggots on hatching from the eggs feed on the developing grains (ovary) in the spikelets resulting in partial or complete sterility. In case of severe infestation only empty earheads are noticed. Life History : Eggs : 100-125 singly in spikelet just near the overy with the help of ovipositor, incubation period 2-4 days. larval period 7-11 days. Pupa-Pupation in spiklet. Pupal period 3-5 days. Adult fly longevity – 1-2 days. Generation – completed in 14-15 days. Overlapping of generations are common. Carryover : It is accomplished by larvae diapausing in soil debris or in panicle residues. Seasonal Occurrence : The pest is active in the months of August to October. High humidity and low temperatures favours its multiplication. Sowing of early maturing high yielding varieties on different dates along with late maturing local varieties provides ideal conditions for rapid multiplication. Management Practices : 1. Adopt zonal system : Sow only one variety in a group of 8-10 villages. Undertake sowing of jowar as early as possible and complete the operation within a week. If possible hybrid varieties should be sown from 20th to 30th July. 2. Destruction of panicle residues prior to onset of monsoon i.e. before May-June by feeding to cattle or by burning before 15th May, to kill hibernating larvae & prevent carry over of pest. 3. Destroy the alternate host plants before flowering. 4. Spraying with 0.1% malathion /0.2% carbaryl/0.05% endosulfan or dusting with malathion 5D/carbaryl 10D/edosulfan 4D @ 20 kg/ha when 1-2 flies /earhead are noticed. Dusting / Spraying should be undertaken early in the morning. Practical Guideline : Draw figures of maggot and adult fly. Minor Pests : 7. Grass Hopper : 1. Deccan wingless grass hopper : Colemenia sphenerioides B. 2. Surface grass hopper: Chrotogonus spp. Acrididae : Orthoptera.
8. Web Worms or Earhead Webber : Stenachroia HMP. Pyralidea : Lepidoptera 9. Hairy Caterpillar Amsacta moorei Bull-Arctiidae : Lepidoptera ; Eurproctis subnotata W.; Lymantriidae : Lepidoptera. 10. Earhead Caterpillar : Helicoverpa armigera H.; Noctuidae : Lepidoptera 11. Mites : Oligonychus indicus H. & Tetranychidae : Acarina.
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Exercise No. 4 STUDIES ON PESTS OF WHEAT, MAIZE , BAJRA AND RAGI
Material : Preserved specimens and affected plant parts. I) PESTS OF WHEAT : The common pests infesting wheat crop in Maharashtra State are given below : Major Pests : 1. Pink borer : Sesamia inferens Wlk. Noctuidae : Lepidoptera Economic Importance : This is widely distributed species and is a common pest of wheat in India. It is sporadic in occurrence. It occasionally attacks maize crop also. Marks of Identification : Moths – small, straw coloured, forewings with faint longitudinal band in the middle while hindwings are pale. Caterpillars – 22 - 25 mm long, pink coloured, smooth with dark spots on the body. Each spot bears a hair. Host Plants : Wheat, maize, sugarcane, jowar, paddy, rabi, barley, oats and guinea grass, etc. Nature of Damage : The young larva hatching from the egg, bores into stem, resulting into the death of the central shoot, commonly known as ‘dead heart’ in early stage of the crop. In the later stage of the crop, this damage results into the formation of empty white earheads. The larva migrates from one plant to another, thereby causing injury to many plants in its life. Life History : Eggs – eggs are laid within leaf sheath or on leaf in clusters. Incubation period 4-9 days. Larva – larval period 3-4 weeks. Pupa-pupation in stem. Pupal period 5-12 days. Life cycle- completed in about 6-7 weeks. Carry Over : The pest hibernate in larval stage in stubbles. Management Practices : 1. Removal and destruction of stubbles after harvest of the crop to kill hibernating larval stages. 2. Remove affected shoots/dead hearts and burn them. 3. Spraying with 0.2% carbaryl immediately after the incidence is noticed. Practical Guideline : Draw the figures of adult and larval stage of this pest.
2. Wheat aphid : Macrosiphum miscanthi (T.) Aphididae : Hemiptera Economic Importance : Wheat aphid is widely distributed in India and sometime causes heavy losses. Marks of Identification : Nymphs are greenish in colour while the adults are greenish – brown in colour with cornicles and winged forms appear in early summer. Host Plants : wheat, barley, oats etc. Nature of Damage : The nymphs and adult suck cell-sap from leaves and ear-heads development of black sooty mould on plant is common feature. Yield is decreased considerably Life History : The female give birth to young ones. Life cycle is completed withing 7-9 days. Management Practices : Spraying of dimethoate or monocrotophos or methyl demeton at 0.03%.
3. Termites or White ants : i) Odontoterms obesus R. ii) Microtermes obsesi H. Termitidae : Isoptera (Described under Polyphagous Pests, Page No. ). 4. Rats : Muridae : Rodentia. (Refer Polyphagous Pests Page No. ). Minor Pests : 5. Jassids : i) Typhlocyba maculifrons M. ii) Amrasca spp. Cicadellidae : Hemiptera. II) PESTS OF MAIZE : The Maize crop is infested by the following important pests: 1. Stem Borer : Chilo partellus S. 2. Pink Borer : Sesamia inferens Wlk. 17
3. Army Worm : Mythimna separata Wlk. 4. Surface Grasshopper : Chrotogonus spp. 5. Deccan wingless Grasshopper : Colemania sphenarioides B. 6. Aphids : Rhophalosiphum maidis F. 7. Delphacids : Peregrinus maidis A. The details of the above pests are given under jowar and wheat. III) PESTS OF BAJRA : Major Pests : 1. Blister Beetle : i) Lyttya spp. ii) Mylabris pustulata Th.;Meloidae : Coleoptera. Economic Importance : It is the only important pests of bajra, which occasionally breaks out in epidemic form in some localities. The grubs feed on the eggs of grasshoppers in soil and are thus beneficial. Marks of Identification : Lytta spp. : Adults medium sized, light brown or greenish blue, soft body. M. pustulata : Adults – bigger sized, yellowish brown stripes across their forewings, soft body. These beetles secretes acidic substance called ‘Cantharidin’ from their body and when crushed on human body cause blisters and hence, they are called ‘Blister beetle’. Host Plants : Bajra, jowar, paddy, cucurbits and beans. Nature of Damage : Beetles attack inflorescence and feed on pollens and petals of flowers and thus adversely affecting grain setting. In case of severe infestation earheads remain without grains (empty earheads). The grubs are harmless to the crop. Life History : Whitish eggs are laid in soil which hatch in about 15 days. The larva feed on eggs of grasshopper and are thus beneficial. Pupation in soil. The beetles emerge from the pupae and remain active from August to December. Management Practices : 1. Collection of beetles by hand net. 2. Dusting the crop with methyl parathion 2D or Endosulfan 4D @ 20 kg/ha as soon as the pest is observed. Practical Guideline : Draw the figures of adult stage of two species of this pest. Besides the above pest, bajra crop is also attacked by the following pests.
2. Army Worm : Refer Polyphagous Pests Page No. ….. Minor Pests : 3. Deccan Wingless Grasshopper:Colemenia sphenerioides B.; Acrididae: Orthoptera. 4. Surface Grasshopper : Chrotogonus spp.; Acrididae : Orthoptera 5. Hairy Caterpillars : Amsacta moorei; Arctiidae : Lepidoptera.
IV) PESTS OF RAGI (FINGER MILLET):
1. Pink borer : Sesamia inferens Wlk; Noctuidae : Lepidoptera (Refer the pests of Wheat). 2. Jassids : Amrasca spp.; Cicaddlidae : Hemiptera (Refer the pests of Cotton). 3. Aphids : Rhopalosiphum maidis F.; Aphididae : Hemiptera. (Refer the pests of Jawar)
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19
Exercise No. 5 STUDIES ON PESTS OF SUGARCANE
Material : Preserved specimens and affected plant parts. About 125 insect and non-insect species have been recorded to infest the sugarcane crop in the country. Of these, about 20 are recorded in the State of Maharashtra. The pests which are commonly found to infest this crop are given below. Borers are the most noxious pests of sugarcane crop and are responsible for heavy losses. Four types of borers viz., early shoot borer, top borer, internode borer and root borers are commonly noticed. Major Pests : 1. Early Shoot Borer : Chilo infuscatellus Snell; Pyralidae : Lepidoptera. Economic Importance : This pest is widespread in all the cane growing areas of the State. However, heavy incidence is noticed in the crop of light soil and where there is shortage of irrigation water especially in the summer months. Heavy losses to the extent of 22 to 33 per cent in yield and 12 per cent in recovery have been noticed. Marks of Identification : Moth-greyish brown or straw coloured, males are smaller than the females. Larva – newly hatched larva is grayish in colour having a dark head and translucent body with spot and hairs. Full grown larva 20-25 mm in length. Host Plants : Besides sugarcane, the pest attack jowar, maize, bajra, hill millets and grasses. Nature of Damage : The pest is mainly injurious to young cane upto 8 weeks after planting. The caterpillars that hatch out from the eggs get scattered and enters into the young shoots by making the hole just above the ground level and tunnels downwards. The central shoots dries up causing ‘dead hearts’. It is a characteristic sign of the presence of the pest within the plants. The dead heart can be easily pulled out. The central shoot dries, rots inside the stem and emits an offensive smell on being pulled out. Life History : Eggs are laid along the sides of midrib on the leaves. About 11-20 egg masses with 16-65 eggs in each cluster are laid by a single female. Incubation period 3-6 days. Larva-larval period 22-31 days. Pupa-pupation inside the stem. Pupal period 5-9 days. Life cycle –completed 34-51 days, No.of generations – 8/year. Carryover : pest hibernates in larval stage in stubbles. Seasonal occurrence : It is active from July to September in adsali planting, November and December in preseasonal planting and January to March in Suru planting. Moderately high temperature with light rains and low humidity increases the early shoot borer activity.
2. Top Borer or Top Shoot Borer : Scirpophaga excerptalis Wlk (= nivella Fab). Pyralidae : Lepidoptera. Economic Importance : It is a cosmopolitan species and is considered to be a serious menace to the sugarcane cultivation in India, however, mild infestation of the pest is noticed in Maharashtra as compared to other borers. Maximum loss to the extent of 18.5 to 55% in yield have been reported in the State.
Marks of Identification : Moth : creamy white, female possess orange coloured tuft of hairs at the tip of abdomen. In males each of the fore wing has a black spot. Caterpillars –yellowish, 25-35 mm in length. Host Plants : In addition to sugarcane it feeds on jowar, rice, maize and some grasses. Nature of Damage : The pest is injurious to the cane in latter stage and persists till havest. The newly hatched caterpillar makes number of small holes on leaves (Shot holes on leaves), enters into 20
midrib of the leaf producing galleries in the midribs. Latters, bores downward into the shoot from the top causing death of central shoot. As a result of such damage the top portion gradually dries up and few internodes already formed mostly go waste. In such cases one or two buds just below the dried top portion sprout and develop into small sized, side canes or side shoots forming a ‘bunchy top’ i.e., bushy appearance. Life History : Eggs-35-216 eggs are laid on underside of leaves. Incubation period 6-7 days. Larva – larval period 3-6 weeks. Pupa-pupation inside the stem in the larval tunnels, pupal period 7-10 days. Life cycle –completed in 5-9 weeks. With 6 generations in a year. Carryover : Full grown caterpillars hibernate in cane tops throughout winter. Seasonal Occurrence : The maximum activity of the pest is observed mostly in October and November in adsali planted cane. High humidity and late rains appeared conducive for the increase in pest population.
3. Internode Borer : Sesamia inferens Walk.; Noctuidae : Lepidoptera. Economic Importance : Though this pest was recorded to be of minor importance in the State of Maharashtra, it is now becoming a serious menace to the cultivation of sugarcane crop. It causes 8 to 34 per cent reduction in yield and 0.06 to 4.20 per cent in recovery. Marks of Identification : Moths – small, 10-12 mm in length, straw coloured. Forewings have marginal dark lines and the hind wings are white. Caterpillars 20-23 mm in length, brownish in colour. Host Plants : Sugarcane, wheat, paddy, maize, jowar and some grasses. Nature of Damage : Infestation of the pest is noticed in all stages of crop growth. Firstly it act as an early shoot borer causing ‘dead hearts’ and latter as an internode borer. The activity as an internode borer starts 3 to 4 months after planting and continues till the harvest. The caterpillar borers at the nodal region and enters into the cane (stem). The hole is usually plugged with excreta. Due to feeding ‘galleries’ are formed inside the cane, the tissues turn red leading to reddish appearance and cane become hard. The larva may attack a number of nodes, habit of boring into one internode after another. Life History : Eggs-are laid between leaf sheath and the stem in clusters. Incubation period 4-9 days. Larva – larval period 31-38 days. Pupa – Pupation inside the stem in the larval tunnels, pupal period 5-12 days. Life cycle : Completed in 6 to 8 weeks, with 5-6 generations in a year. Carryover : Larva overwinters in canes or stubbles from November to February. Seasonai Occurrence : The pest is found throughout the year and infestation is noticed from May to September. High temperature associated with light showers and low humidity helps in rapid multiplication of the pest. This pest is mostly active during dry and warm conditions.
4. Root Borer : Emmalocera depressella S.; Pyralidae : Lepidoptera. Economic Importance : It is one of the minor pests of sugarcane and attack the underground portion of the stem. It is therefore, not a true root pest but in usage, it has been named as root borer. Marks of Identification : Larva creamy white, 30 mm, the adult is yellow brown with white hind wings. Host Plants : Sugarcane and jowar. Nature of Damage : On hatching caterpillar enters the stem near the root zone through a fine hole and feeds on inner contents. Cenral leaf whorl dies and forms a ‘dead heart’. It is not easily pulled out like that of early shoot borer. Life History : Oviposition –on leaves/stem/ground. Incubation period 5-8 days. Larval period – 4 weeks. Pupation takes place inside the cane, pupal stage lasts for 9-14 days. Life cycle is completed in 6-7 weeks. Pupation inside canes. Management Practices : (Borer Complex) Borers being an internal feeders are extremely difficult to control. Both preventive and curative measures are necessary to keep them under check. Since 21
most of the borers occur together and the type of damages caused by them is more or less common, the measures for their control are also given together. 1. Collection and destruction of egg masses. 2. Removal of dead hearts. 3. Early earthing up of canes, usually a month after planting helps in minimizing the damage of early shoot borer and root borer. 4. Timely planting of cane – Adsali in July-August, Preseasonal in October and Suru in December – January. Late planted crops (apart from giving lower yields) are badly attacked by the shoot borer, causes gaps in the stand of cane and set – back to growth and yield. 5. Profuse and timely irrigation, mulching with trash at planting or germination for early shoot borer. 6. Digging out the clumps (stubbles) after harvest to kill hibernating larvae of root borers, early shoot and internode borers. 7. Burning of trash at harvest to prevent carry-over of internode borer infestation to the succeeding crops. 8. Biological control : Release of eggs parasitoid, Trichogramma chilonis Ish. @ 50,000 Adults/ha/week in 6-8 instalments. Trichocards (Corcyra eggs parasitized by Trichogramma) are commercially available.
Chemical Control : (For Early Shoot Borer) : Drenching the soil with 0.1% lindane 20 EC or Cholrpyriphos 20 EC (i.e. 5 litres in 1000 litres of water/ha.) immediately after planting in the furrow by using water can/sprayer. Spraying the crop with 0.05% endosulfan as soon as incidence is noticed. (ETL- 15-22% incidence in top shoot borer.).
5. Sugarcane Pyrilla or Leaf Hopper : Pyrilla perpusilla Walk; Fulgoridae: Hemiptera. Economic Importance : It is a major pest of sugarcane and breeds practically throughout the year. It is distributed throughout India. Since 1950, the pest is noticed in the endemic form in the area of Deccan canals of Maharashtra State. Due to constant sucking of the cell sap, losses to the extent of 26 to 35 % in yield and 2 to 5% in sucrose has been recorded. Besides, 2.25 to 4.5 per cent decrease in production of gur has been reported. Under epidemic conditions nearly 50% decrease in recovery occurs and gur will not set. Marks of Identification : Adults- straw coloured, 2 pairs of wings folded like a roof on the back, head extended like a pointed beak. Nymphs-newly hatched ones are milky white with a pair of characteristic processes/filaments covered by wax, very active and found in large numbers on cane. Host Plants : Besides sugarcane, it also feeds on wheat, barley, jowar, maize, bajra etc. Nature of Damage : Both nymphs and adults suck the cell sap from the lower surface of leaves. As a result plant loose turgidity, begin to wither and get dried up. The sucrose % of the juice is adversely affected. They also excrete honeydew like substance, that spreads on the leaves on which black fungus (Capnodium spp.) develop, which adversely affect the photosynthesis and the yield. Life History : Eggs are pale greenish yellow, single female lays about 400 eggs on lower surface of leaves and also between the detached leaf sheath and the stem, covered with white, cottony waxy filaments. Incubation period 7-14 days in summer and 30-40 days in winter. Nymphs – nymphal period 50-60 days (5 instars) in summer and 50-80 days in winter. Life cycle : completed in 60 days in summer and 120 days in winter, 3-5 generations in a year. Carry Over : Through alternate host plants, overwinters mostly in adult stage. Seasonal occurrence : Cold winds and high humidity help in rapid multiplication. Low rain fall or prolonged dry spell and low temperature during monsoon also seem to be conducive for its 22
profuse multiplication. Severe infestation of the pest is noticed during July and August in the endemic area. Management Practices : 1. Collection and destruction of egg masses. 2. Removal of 5-6 lower most leaves helps in reduction of pyrilla population as maximum egg laying takes place on such leaves. 3. Biological control : Release of lepidopterous nymphal parasitoids viz., Epiricania melanoleuca F. @ 5000 cocoons/ha or 5,00,000 eggs/ha effectively control the pyrilla. After establishment of parasitoids, insecticides should not be used and avoid trash burning to prevent destruction of hibernating eggs of parasitoids on dry leaves. Use of Metarrhizium anisopliae M. and Aspergillus flavus L. fungi are also effective against the pest (nymphs and adults). 4. Chemical control: Hand spraying of 0.035% endosulfan / 0.03% quinalphos/0.03% fenitrothion/0.05% malathion/0.03% monocroto-phos /0.03% dimethoate as soon as 3-5 individual eggs or nymphs or adults/leaf are noticed in May/June. Aerial spraying of malathion ULV/endosulfan 35 EC/fenitrothion 100 EC is also recommended.
6. Sugarcane Woolly Aphids: Ceratovacuna lanigera Zehnter; Aphididae: Hemiptera. Economic Importance : Sporadic occurrence of this pest is observe in some sugarcane growing pockets of Maharashtra from last few years. Marks of Identification : Nymphs have elongate, ovoid body with pale yellowish white colour. As nymphs develop, gradually covered with white powdery secretion which covers body segments. The adults are apterous or alate (winged) forms, about 1 to 2 mm in length and covered with white cotton like secretion. Host Plants : Wild and cultivated sugarcane species. Nature of Damage : The aphids form a colony on the under surface of sugarcane leaves. Both nymphs and adult suck the cell sap from leaves and excrete honey dew resulting subsequent development of black sooty mould on plant resulting adversely on photosynthesis. It affect adversely on growth, sugar content and yield of crop. The fodder quality of leaves (tops) is also adversely affected. The incidence of the pest is most severe from June to September when the humidity is high. Life History : The woolly aphid is an viviparous insect reproduce parthenogenetically with 10 to 60 offsprings per female on ventral surface of leaf. The nymphal period is 23-40 days. Adult period 8 to 36 days. Life cycle is completed within 4 to 6 weeks. Management Practices : 1. Adoption of strip planting method so as to wide space between the paired rows. 2. Mechanical measures like collection and destruction of the infested leaves as soon as localized infestation is noticed. 3. Release of lepidopterous predator Dipha (Conobathra) aphidivora or other predators like Micromus, Chrysoperla spp. 4. Spraying of dimethoate, endosulfan, malathion or methyl demeton at 0.05% or dusting of methyl parathion 2D @ 25 kg/ha.
7. White Grub : Holotrichia serrata F.; H. consanguinea Bl. Leucopholis lepidophora Burm. Scarabaeidae : Coleoptera. (Refer the Polyphagous Pests Page No. ……………)
8. Termites or White Ants : Odontotermes spp. Microtermes spp. (Refer Polyphagous Pests Page No. ……………)
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9. Sugarcane Mites : Oligonychus indicus Hirts.; Tertranychidae : Acarina. (Refer the Polyphagous Pests Page No. ) Minor Pests : 10. Scale Insects : Melanaspis glomerata Green, Coccidae : Hemiptera.
11. Mealy Bugs : Saccharicoccus sacchari Ckll.; Pseudococcidae : Hemiptera.
12. White Fly or Mealy Wings : Aleurolobus barodensis Mask.; Aleyrodidae : Hemiptera.
13. Grasshopper : Hieroglyphus banian Fab.; Acrididae : Orthoptera
14. Rats : Rattus rattus Linn. & R. norvergicus Birk.
15. Aphids : Melanaphis sacchari Z.; A. maidis F. and A. sacchari Z. Aphididae : Hemiptera.
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Exercise No. 6 STUDIES ON PESTS OF COTTON, SUNNHEMP AND AMBADI
Material : Preserved specimens and affected plant parts. I) PESTS OF COTTON : Of the 134 pests recorded on cotton, 25 pests have been reported in the State of Maharashtra infesting the crop and the important pests are described below : Major Pests : 1. Jassid or Leaf Hopper : Amrasca biguttula Ishida; Cicadellidae : Hempitera Economic Importance : It is a cosmopolitan and polyphagous species widely distributed in the Indian Union. It occurs in all the cotton growing areas of the State. Heavy incidence of the pest is noticed in irrigated cotton. Marks of Identification : Adult-wedge shaped, 3.5 mm in length, pale green, black spot on each of the fore wings and 2 spots on vertex. Nymph –wingless, pale greenish, walk diagonally. Host Plants : It is polyphagous species infesting cotton, bhendi, potato, brinjal, sunflower etc. Nature of Damage : Both nymphs and adults suck the cell sap from the lower surface of the leaves and inject their toxic saliva into the plant tissues and produce a characteristic “Hopper Burn” symptoms on leaves wherein the margins turn yellowish initially and subsequently turn reddish and curl. In case of heavy infestation, the leaves show brown necrotic patches and the growth of the plant remains stunted thereby affecting the yield adversely. Life History : Eggs-female lays 30 eggs in leaf tissues singly inside the leaf veins which hatch in 4-11 days depending upon the climatic conditions. Nymphs - nymphal stage 7-21 days (moult 5 times). Life cycle-completed in 2 to 4 weeks. Generation – several overlapping generations in a years. Seasonal occurrence : Active during July to September. Excessive rainfall and irrigated conditions are conducive for the multiplication of the pest and the incidence is observed to be more pronounced in irrigated cotton as compared to rainfed cotton. Practical Guideline : Draw fugures of adult jassids and the plan showing “Hopper Burn” Symptoms.
2. Aphids : Aphis gossypii Glover; Aphididae : Hemiptera Economic Importance : It is a cosmopolitan and polyphagous species noticed in all the cotton growing areas of the state. Marks of Identification : Adult – oblong, 2 mm long, yellowish to dark green or black in colour, cornicles on abdomen, mostly wingless, winged forms are noticed mostly in the beginning and towards the end of the season, wings are thin, transparent and held like a roof of the body Host Plants : Cotton, brinjal, bhendi, chillies, potato, pomegranate, etc. Nature of Damage : Nymphs as well as adults suck the cell sap by remaining on the lower surface of leaves and impair the vitality of the plants. In severe infestation the leaves curl badly and growth of the plant remain stunted. Besides sucking the sap from the leaves, these insects also excrete a honey-dew like substance which attracts the black sooty mould (Capnodium spp.) which adversely affect the photosynthesis. Life History : They reproduce viviparously and parthenogenetically. A single female produces 8-20 nymphs/day. Nymphs moult 4 times. The life cycle completed in 7-9 days, there are many generations in a year. Seasonal occurrence: The pest is very active during early part of rainy season and in the later period of winter season. Natural Enemies: Predators – Ladybird beetle, Coccinella septumpunctata and green lacewing Chrysoperla carnea. Practical Guideline : Draw the figure of aphid. 25
3. Thrips : Thrips tabaci Lind, Scirtothrips dorsalis, Hood.; Thripidae : Thysanoptera. Economic Importance : It is a consmopolitan and polyphagous species distributed all over the state wherever cotton is grown. It breaks out in serious form especially in early stage of the crop growth. Marks of Identification : Adults – minute, delicate insects (about 1 mm long), light yellow, the wings have a fringe of hairs, Nymphs – very minute, whitish yellow. Host Plants : Cotton, mango, tondli, bottle gourd and guava. Nature of Damage : Both nymphs and adults with their rasping and sucking type of mouth parts scrap the epidermal tissues of leaves and suck the oozing cell sap. As a result of their feeding, leaves become brownish. Excessive feeding on leaves lead to their curling and the plants remain stunted. Life History : Female breeds sexually as well as parthenogenetically. Eggs : female can lay 30-50 eggs during her life time in leaf tissues of veins on lower surface of leaves. Incubation period 2-5 days. Nymph-nymphal period 7 days (moult 3 times) Life cycle completed in 4 weeks Adult female lives for 10-15 days. Parthenogenesis is common and progeny produced in this way consists of females only. Seasonal occurrence – Pest is active in post – monsoon period or in dry spell during monsoon. Practical Guideline : Draw figure of adult thrips. Management Practices : (Aphid, Jassid and Thrips). 1. Seed treatment with imadacloprid @ 5 g/kg seed or granular application at the time of sowing with phorate 10G @ 1-1.5g at each spot, Or spraying with 0.03% dimethoate./methyl demeton. Spraying should be undertaken when ETL reaches to : Aphids – 10 aphids / plant or 15-20% plants are infested. Jassids- 2 jassids/leaf. Thrips – 10 thrips/leaf or 15-20% plants are infested.
4. Bollworms : a) Spotted or spiny bollworms (SBW) : i) Earias vittella Fb.; ii) E. insulana B. Noctuidae : Lepidoptera. Economic Importance : It is a cosmopolitan species and is distributed throughout the cotton growing areas of the State. In Maharashtra, shoot damage to the extent of 30% has been reported. The shedding of squares and bolls to the extent of 50-60% has been recorded. Similarly, the loss in yield of kapas (seed cotton) has been estimated to be around 20 per cent. Marks of Identification : E. vittella adults have pale white upper wings with a broad greenish band in the middle, 10 mm in length. E. insulana adults have completely green upper wings. Caterpillars – brownish white with number of black and brown spots on the body and hence the name ‘spotted bollworm’, 19 mm long. Host Plants : Oligophagous, infesting cotton, bhendi, ambadi, holly hock, mudrika and other malvaceous plants. Nature of Damage : In early stage of the crop growth the larvae bore into the growing tender shoots and feed internally, resulting into drooping and drying of such shoots. With the onset of flowering, the larvae bore into the bunds and flowers and make them drop down on ground. Latter, when the bolls are formed, they attack them. The infested bolls show holes plugged with the excreta. The infested buds and bolls are mostly shed but if they remain on the plant they open prematurely and the lint obtained from them is of inferior quality. Life History : Eggs – A female lays 200 – 400 eggs in 5-23 days on top tender leaves, floral buds, bracts and bolls singly or in batches, eggs hatch within a week and tiny larva move freely for some time on the plant and then bore. Larva : They become full grown in 2-3 weeks depending upon climatic conditions. Pupa : pupation in the soil or on plant in squares or bracts in silken cacoons. Pupal period lasts for 1-2 weeks. Generation – life cycle completed in 18-46 days and there are several generations in a year, Carryover : summer bhendi is one of the important source 26
of carryover of the pest and hence avoid growing of bhendi and other malvaceous crops during off season. (i.e. summer season), which serve as alternate host for spotted bollworm. Practical Guideline : Draw the figures of larva, moth, damaged shoot and boll. b) Pink bollworm (PBW) : Pectinophora gossypiella S.; Gelechidae : Lepidoptera Economic Importance : This is one of the most destructive pests of cotton having been reported from almost all countries of the world. In Maharashtra it is distributed in all the cotton growing areas. Shedding of bolls to the extent of 60% (Marathwada), while infestation of bolls to the extent of 50% (Jalgaon) has been reported. Marks of Identification : Moth- small, 3-6 mm in length, brown with numerous black spots on the wings. Caterpillar pinkish, 18-19 mm in length. Host Plants : Oligophagous, infesting cotton, bhendi, ambadi, hollyhock, mudrika and other malvaceous plants. Nature of Damage : Unlike the spotted bollworm, the pink bollworm never attacks the shoots; but infest floral buds, flowers and bolls. In the beginning; the caterpillars feed on floral buds and flowers and cause their shedding. Later on they bore into the bolls and feed on inner contents. Caterpillar feeds on the seeds and moves to adjacent locule by making hole through the septum. Ginning percentage of seeds and spinning qualities of kapas are adversely affected. As caterpillars enter the bolls, their entry holes which are very minute, get closed and it becomes extremely difficult to locate the infested bolls until they drop down on the ground. Life History : Eggs : female lays about 100-150 eggs in 3-5 days singly on underside of leaves, floral buds, bracts and bolls. Eggs hatch within a week but hatching delays under severe cold conditions. Larva : full grown in 9-21 days and pupates by spinning cacoon on the bract or in falien leaves, flowers or even in soil. Pupa : pupal stage last for 6-20 days. Generation. There are two types of generations viz. short cycle and long cycle. The life history mentioned above is in the case of “short cycle generation”. In the “long cycle generation” the full grown larva without undergoing pupation remains in hibernating stage in seed even up to 2 years. As many as 9 generations are completed in a year. Carryover : Through seed in the form of hibernating larva, but quite negligible in over state. Majority of them hibernate in pupal stage (cacoons) among the shed bolls, other plant debris or in cracks in soil. Practical Guideline : Draw the figures of caterpillar, moth and attacked bolls. c) American bollworms : Helicoverpa armigera H.; Noctuidae : Lepidoptera. (Refer Polyphagous Pests Page No.…………..). Management Practices : (Bollworm Complex) Preventive Measures : 1) Clean-Up Campaign : Immediately after harvesting is over, the stalks, leaves, infested bolls on the plants and those lying on the soil should be collected and burnt. 2) Fumigation of Seeds In Storage : Seed fumigation should be done with Alluminium phosphide @500 g/100cu.m. of space for 24 hrs. to kill hibernating larvae of PBW. Fumigation should be carried out carefully and strictly under expert supervision. Mechanical Measures : 1) If the infestation of SBW is observed, remove and destroy the affected shoots along with larvae or the affected shoots should be pressed to kill the larvae inside. Biological Control : 1) Field releases of following parasitoids @ 50,000 parasitized eggs of corcyra/ha. Trichogramma chilonis (an exotic egg parasitoid) Chelonus blackburni Cam. (an exotic egg-larval parasitoid) 50,000 adults/ha. Bracon kirkpatrickii, W. (an exotic larval parasitoid) Apanteles angaleti M. (an indigenous larval parasitoid). Chemical Control
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1) Spraying the crop with 0.0075% cypermethrin/0.0025% decamethrin / 0.0125 % fenvalerqte / 0.0092 % fluvalinate or 0.2 % carbaryl / 0.06 % endosulfan / monocrotophos / 0.05 % quinalphos / phosalone or dusting the crop with carbaryl 10D@ 20 kg/ha at 5% infestation on squares, flowers and bolls (ETL). 2) Spraying with Bt/HaNPV for American bollworm.
5. Mites : 1. Red mite – (Tetranichid mite); Tetranychus spp. Teranychidae : Acarina 2. Woolly mite – (Eriophyid mite); Aceria gossypii B; Eriophyidae: Acarina In recent years, the problem of phytophagous mites is assuming serious form. One of the reason for this is the intensive and indiscriminate use of chlorinated hydrocarbon and carbamate insecticides in plant protection work which are reported to be ineffective against mites but are responsible for destruction of their natural enemies. Red mites are common in Maharashtra infesting variety of crops. Biology – Red Mites : Adults are extremely small, 0.6 x 0.2 mm, Body unsegmented not divided into cephalothorax and abdomen. 4 Pairs of legs (in larvae 3 pairs only), life cycle consists of an egg, 3 nymphal and adult stages. The nymphal stage are called protonymph (larva), deutonymph and tritonymph. Larva, in most cases resembles the adult. Woolly Mites : They are different from all other Acarina. They have vermiform body, distinctly divisible into a cephalothorax and a long tapering abdomen and only 2 pairs of legs situated near the anterior end of the body. Both in the adult and immature stages, mouthparts are adopted for biting, piercing and sucking. Life cycle consists only two nymphal instars which are not very different from the adult. Nature of Damage : Red mites are abundant on lower surface of leaves. The nymphs and adults suck the cell sap from the leaves which as a result turn reddish brown and ultimately dry and drop down. The woolly mites feed on epidermal tissues of leaf and cause irritation due to which a growth of dense whitish hairs arises on both surfaces of leaves as well as on the infested shoots. Heavily infested plants shed their bolls. In Maharashtra, red mites are more common than woolly mites. Life History : Eggs : female lays 33-90 eggs on leaves which hatch in 4-6 days. Larva : larval period 4- 7 days. Nymph : nymphal period 7-16 days. Life cycle: completed in 15-29 days depending upon climatic conditions. Generation : several generations in a season. Management Practices : Dusting of sulphur @20 kg/ha or spraying with 0.2% wettable sulphur control the mites effectively. Practical Guideline : Draw the figure of mites.
6. Red Cotton Bug : Dysdercus cingulatus Fb.; Pyrrhocoridae : Hemiptera Marks of Identification : Adult bug : small (12-13 mm in length), red in colour (except eyes, scutellum and antennae which are black coloured.), black spot on each of the forewings and white bands on the abdomen. Nymphs : red, smaller and wingless. Host Plants : Oligophagous, infesting cotton, bhendi, ambadi, holly hock and other malvaceous plants. Nature of Damage : Both nymphs and adults suck the cell sap from the leaves, tender shoots and tender bolls and impair the vitality of plant. The attacked bolls open badly and produces a lint of poor quality. In addition, they also feed on the seed and lower their oil content. The infested seeds become unfit for sowing. Due to excreta of the insect and the crushing of the nymphs during ginning the lint gets stained and hence it is commonly called cotton stainer. The insect is reported to introduce a bacterium, Nematosopora gossypii into the bolls which also stains the cotton fibre. Life History : Eggs – femal lays 100-130 eggs in soil near the plant. Nymph-nymphal period 30-35 days (4 moults). Life cycle – completed in 6-8 weeks.
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Management Practices : Dusting with methyl parathion 2 D/endosulfan 4 D @ 20kg/ha. immediately after the appearance of the pest. Dusting should be done both on the crop and on soil. Practical Guideline : Draw the figures of nymph and adult.
7. Dusky Cotton Bug : Oxycaraenus hyalipennis K; Lygaeidae : Hemiptera. Marks of Identification : Adults : small (6 mm long), dusky in colour : Nymphs :reddish brown, turn into dusky brown. Host Plants : Cotton, bhendi and other malvaceous plants. Nature of Damage : Pest attacks open bolls and those damaged by bollworms. Nymphs and adults suck the sap from immature seeds in open bolls, as a result seeds do not develop properly. Besides, due to their crushing in ginning the lint gets stained. Life History : Eggs : The cigar shaped whitish eggs are laid in cluster in the lint of half opened bolls. Hatch in 5-6 days. Nymph : nymphal period 2 weeks (moult 6 times). Seasonal occurrence : the pest is active from November to February. Management Practices : Given under red cotton bug.
8. Cotton Leaf Roller : Sylepta derogate Fb.; Pyradidae : Lepidoptera. Host Plants : Cotton, bhendi, etc. Nature of Damage : The caterpillars roll-up the cotton leaves and feed on them from margin by remaining inside such rolls. Life History : Eggs laid on surface of tender leaves. Pupation takes place within.leaf rolls. Leaf cycle completed in 4 weeks. Management Practices : 1) Removal and destruction of rolled-up leaves. 2) Dusting the crop with methyl parathion 2D or endosulfan 4D @ 20-25 kg/ha or spraying of carbaryl 50 WDP 0.2%.
9. Cotton mealy bug : Phenaccocus solenapsis Tin. Peudococcidae : Hemiptera. Economical Important : Recently the species P. solenapsis is predominantly observe on cotton. Marks of Identification : Body oval (5 mm), somewhat rounded in lateral view, dark green almost black, cover with white, thin mealy wax, a pair of dark longitudinal lines on dorsum, ovisac absent from dorsum, but well developed ventrally with 18 pairs of lateral wax filaments, posterior pair longest. Host Plants : Highly polyphagous, feeding on cotton, other crops and weeds, atleast 14 host families. Nature of Damage : Both nymps and adult females suck the cell-sap from the leaves, flowers and bolls. Excretion of honeydew and development of sooty mould dropping of flowers and bolls and adversely effect on growth of plant. Drying of soots in case of severe infestation. Life History : The eggs are not detectable. There are three nymphal and adult stage. The stages last with an average of 6, 8, 10 and 13 days respectively. The adult stage lasts 10 to 30 days. Management Practices : 1. Collection of severely infested twigs and their distraction 2. Spraying of Verticillium leccanii @ 0.2 % or monocrotophos or diamethoate or qunalphos or clorpyriphos @ 0.05% 3. Use of cryptolaemus predators. Minor pests : 10. White Fly : Bemisia tabaci G.; Aleyrodidae : Hemiptera 11. Scale Insects : Pulvinaria maxima G.; Coccidae : Hemiptera 29
12. Cotton Ash Weevil : Myllocerus maculosus D.; Curculionidae : Coleoptera. 13. Reniform Nematode : Rotylenchulus reniformis; Hoplolaimidae : Tylenchida.
II) PESTS OF SUNNHEMP AND AMBADI : Major Pests : 1. Hairy Caterpillars : Argina spp.; Arctiidae : Lepidoptera Marks of Identification : Black hairs all over the body of caterpillar. Moths are pale, whitish with red black soots on upper wings and black marginal blatches on lower wings. Host Plants : Polyphagous pest feeding on sunnhemp, ambadi, grasses etc. Nature of Damage : The caterpillars feed on leaves and occasionally also bore into seed capsules. Life History : The moths lay small whitish eggs on the tender leaves and shoots. Incubation period 6-9 days, larval period 2-3 weeks pupal period 1 week. Total life cycle is completed within 4 to 7 weeks. Pupation takes place either in the leaf folds or in the soil. Management Practices : 1) Clean cultivation 2) Handipicking of caterpillars in the early stage of infestation, alongwith leaves. 3) Dusting with endosulfan 4 D or methyl parathion 2D @ 20 kg/ha as soon as incidence is noticed. Or spraying with 0.05% endosulfan or 0.1% carbaryl 50 WDP. Practical Guideline : Draw the figures of moth and caterpillar.
2. Spiral Borer of Mesta / Stem Borer : Agrilus acutus Thumb.; Buprestidae : Coleoptera. Economic Importance : This pest is commonly observed in Bihar, Uttar Pradesh and Madhya Pradesh. Marks of Identification : It is a minute bronzy or metallic blue coloured beetle with cylindrical body. The grubs are brownish pinkish. Host Plants : Mesta (Ambadi). Nature of Damage : The damage is caused by the grubs by feeding inside the stem on woody tissue. During feeding the grub travels throughout the entire length of the stem in a spiral manner. A portion of the infested region swells-up considerably to form an elongated gall, the portion above the gall dries up and breaks. Life History : The eggs are laid on stem preferably on the nodal region below the leaf – base. Pupation takes place inside the stem. Incubation period 1 to 2 weeks. Larval period 25 – 30 days. Pupal period 8-10 days. Total life cycle – 5 to 6 weeks. Management Practices : 1. Collection and destruction of infested plants. 2. Swabbing the stem with 2.5 % methyl demeton 25 EC or dusting with endosulfan 4D or Methy parathion 2D @ 20 kg/ha.
Minor Pest : 3. Jassids : Amrasca biguttula Ishida; Given under cotton. 4. Aphids : Aphis gossypii G.; Given under cotton. 5. Flea Beetle : Longitarsus spp.; Chrysomelidae : Coleoptera. 6. Capsid Bug : Ragmus importunitas D.; Miridae : Hemiptera
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Exercise No. 7 STUDIES ON PESTS OF OILSEED CROPS
Material : Preserved specimens and affected plant parts. I) PESTS OF GROUNDNUT : Groundnut is one of the major oilseed crops of the State, which is attacked by about a dozen insect and non-insect pests. The more important are aphids, leaf miner, pod sucking bug, white grub and termites. Major Pests : 1. Groundnut Leaf Roller or Groundnut Leaf Miner: Aproaerema modicella Devant Gelechidae : Lepidoptera. Economic Importance : Though the pest was recorded to infest the crop in Nagpur area, it has been assuming serious form in the State only during last 10 years. Though polyphagous, considered to be serious only on groundnut. Marks of Identification : Moth-small, 8-10 mm in length, wings are grayish with a pale white dot on each of the forewings. Caterpillar – small, 6-8 mm long, cylindrical tapering posteriorly, brown or light green in colour. Host Plants : Polyphagous infesting groundnut, soybeans, red gram (tur) etc. Nature of Damage : The larva mines the upper epidermis of the leaves during early stage of their growth. The mined leaves within a few days show brown streaks. Later the larvae bite their way out from the mines and fold the leaves or bring two adjacent leaves together and feed on them. As a result, leaves dry and the plant wither adversely affecting the yield. Life History : Eggs are laid on leaves and tender shoots. Incubation period 3-4 days. Larva-larval period 9-17 days. Pupa – pupation in leaf folds or in leaf mines. Pupal period – 7days. Life cycle : Completed in 15-28 days, with many generations in a year. Management Practices : Spraying the crop with 0.01 % cypermethrin / 0.01 % fenvalerate / 0.0025% decamethrin/0.2% carbaryl/ 0.05% monocrotophos/ 0.05% quinalphos or dusting the crop with quinalphos 1.5 D/ methyl parathion 2 D/ phosalone 4D / malathion 5 D @ 20 kg/ha as soon as 2 live larvae/ plant or 10 % mined leaves are noticed. Practical Guideline : Draw the figure of adult moth of this pest.
2. Groundnut Aphids : Aphis craccivora Koch.; Aphididae : Hemiptera. Economic Importance : This is a cosmopolitan and polyphagous species breaks out in an epidemic form almost every year in all the groundnut growing areas of the State and causes heavy losses. Marks of Identification : Adult –dark olive brown to black with dark medium bars on the abdomen. Wlinged forms have black wings. The aphid colonies are noticed on underside of leaves, top shoots and stem. Host Plants : Tur, wal, cowpea, beans, pulses etc. Nature of Damage : Both nymphs and adults suck the sap from tender leaves and shoots. As a result, the vitality of the crop is reduced which adversely affects the yield. It also excrete honeydew like substance on which develops a black saprophytic fungus which interferes with the photosynthetic activities of the plants. Besides, the pest is also known to serve as a vector of virus disease, commonly known as “rosette” of groundnut. Life History : Both winged and wingless forms reproduce viviparously and parthenogenetically. On an average single apterous and alate female produces 54 and 47 young ones in 8 to 17 and 14-18 days, respectively. Management Practices : Spraying with 0.02% methyl demeton / formothion / 0.05 % monocrotophos or dusting with malathion 5 D / quinalphos 1.5 D / endosulfan 4 D / phosalone 4 D @ 20 kg/ha as soon as incidence is noticed. Practical Guideline : Draw the figure of winged and wingless aphids.
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3. Thrips : Caliothrips indicus Bagn.; Thripidae : Thysanoptera. Economic Importance : It is responsible for transmitting “Tomato spotted wilt virus” in groundnut and cause “bud necrosis” disease. The loss in yield may extend upto 80 per cent. Nature of Damage : Nymphs and adults suck the cell sap from the leaves. The infested leaves turn yellow and margins curl up. Often there is leaf shedding. Severely infested plants appear blighted and dried up. Management Practices : 1. Spraying with 0.05% monocroptophos as soon as incidence of the pest is noticed. 2. Groundnut crop should be sown in last week of December in south Konkan and between last week of December to first fortnight of January in North Konkan in bud necrosis affected area to minimize the incidence.
4. White Grub : Lachnosterna consanguinea Bl.; Holotrichia serrata F.; Scarabaeidae : Coleoptera. (Refer Polyphagous Pests Page No. …)
5. Pod Sucking Bug : Elasmolemus sordidus Fb., Lygaeidae : Hemiptera. Nature of Damage : Both nymphs and adults suck the sap from the developing seeds. As a result the seeds get shriveled, become rancid and give bitter taste. The oil content and germination percentage of infested seeds are also adversely affected. Besides, causing damage in the field it continues to infest the pods in threshing yard and even in storage. Management Practices : Spraying the crop with 0.05% malathion. Practical Guideline : Draw the figures of nymph and adult stages of this pest.
Minor Pests : 6. Termites : Odontotermes obesus Ramb.; Termitidae : Isoptera. 7. Jassids : Empoasca kerri; Jassidae : Hemiptera. 8. Hairy Caterpillars : Red Hairy Caterpillar : Amsacta moorei Butler & Bihar Hairy Caterpillar : Spilosoma obliqua Walk.; Arctiidae ; Lepidoptera.
II) PESTS OF SAFFLOWER : It is another major oilseed crop of the State. The crop suffers badly from the ravages of few pests which cause considerable losses every year. Major Pests : 1. Safflower Aphids : Uroleucon compositae Th.; Aphididae : Hemiptera. Economic Importance : It is the most notorious pest of safflower having been reported from all areas of the State, wherever the crops is grown. Heavy infestation of the pest is noticed in late sown crops. Marks of Identification : Adult – small, 2 mm in length, shining black, soft bodied insect. Nymphs – reddish brown in colour. Host Plants : Safflower, niger, sesamum, citrus, ornamental plants like dahlia, cornflower, caliopsis etc. Nature of Damage : Nymphs and adults suck the cell sap from the leaves and tender shoots, impaire the vitality of plant. In case of severe infestation entire plant may be covered by pest, showing blackish appearance. Besides sucking the sap from the plant, they also excrete a honey dew like substance which attract the black sooty mould adversely affecting photosynthesis. Life History : Aphids reproduce viviparously and parthenogenetically. Single female produces 30 youngones. A generation completed in 7-9 days. Seasonal Occurrence : The pest is active in November and December. Management Practices :
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1. Early sowing in the first week of October. In drought prone areas sowing of crop second week of September is recommended. 2. Spraying the crop with 0.03% methyl demeton / dimethoate / thiometon or 0.05% endosulfan/ quinalphos/ fenthion or 0.1% carbaryl/ malathion or dusting phosalone 4 D / methyl parathion 2 D @ 20 kg/ha as soon as incidence is noticed. Practical Guideline : Draw the figures of wingless and alate forms of this pest.
2. Leaf Eating Caterpillar: Prospalta (Perigaea) capensis G. Noctuidae: Lepidoptera Economic Importance : The pest is sporadic in occurrence but occasionally assume serious form and cause considerably losses. Marks of Identification : Moth – medium, dark brown in colour with blackish brown forewings and light brown hindwings. Caterpillar – greenish, become dark brown, 25 mm long. Host Plants : Safflower, niger, jute, etc. Nature of Damage : Larvae feed voraciously on the leaves and in case of severe infestation completely defoliate the plants. Life History : Eggs are laid on leaves and tender shoots. Incubation period 4 days Larva : larval period 15-20 days. Pupa : Pupation in soil. Pupal period 8 days. Life cycle : completed in 4 weeks. Management Practices : Dusting of insecticides as given under aphids. Practical Guideline : Draw the figure of adult stage of the pest.
III) PESTS OF SESAMUM : The Important pest infesting the crop in the State are sesamum gall fly, leaf eating caterpillar, pod sucking bug and leaf roller.
Major Pests : 1. Sesamum Gall Fly : Asphondylia sesami Felt.; Cecidomyidae : Diptera. Economic Importance : It is the most noxious pest of sesamum and may cause heavy losses. It is serious in Nagpur region and incidence to the extent of 20 % has been reported. Marks of Identification : Adult fly – small 2.5 mm in length, mosquito like fly, ashy colour. Maggot – small, dirty white. Host Plants : Cluster beans and sesamum. Nature of Damage : The maggots feed on buds and cause gall formation in place of pod. Life History : Eggs – are laid on floral buds, flowers and developing capsules. Incubation period 3 to 4 days. Larval period 15-20 days. Pupa – pupation in galls. Pupal period 6-10 days. Life cycle completed in 3 - 4 weeks. Management Practices : 1. Removal and destruction of infested buds with maggots. 2. Do not allow to grow stray plants in off season. 3. Grow resistant variety – N-166-5. 4. Spray with endosulfan or dimethoate at 0.05%. Practical Guideline : Draw the figure of adult of this pest. 2. Seasmum Leaf Eating Caterpillar or Til hawk moth : Acherontia styx West; Sphingidae : Lepidoptera. Economic Importance : Though the pest is sporadic in occurrence, it occasionally assumes serious form and cause considerable losses. Marks of Identification : Moth – fairly large, stoutly built with dark grey bluish thorax, abdomen yellowish with black transverse bands, forewings dark brown. Caterpillar – stoutly built with horn like process at the anal end and 8 strips on the body, greenish brown in colour. Host Plants : Sesamum, Dolichos spp and Jasminum spp. Nature of Damage : Caterpillars feed voraciously on leaves and defoliate the plants.
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Life History : Eggs – are laid on leaves. Incubation period 8-10 days. Larva-larval period 2 months. Pupa-pupation in soil. Pupal period 1-2 months. Life cycle : completed in 3-5 months. Management Practices : Spraying the crop with 0.05% endosulfan / quinalphos / fenthion / 0.2% carbaryl/ 0.01% fenvalerate as soon as incidence is noticed. Practical Guideline : Draw the figures of adult and caterpillar of this pest.
Minor Pests : 3. Pod Sucking Bug : Elasmolomus sordidus Fb.; Lygaeidae : Hemiptera.
IV) PESTS OF SOYBEAN : Major Pests : 1. Girdle Beetle : Obereopsis brevis G.; Cerambycidae : Coleoptera Marks of Identification : The adult are small brownish black beetles with long antennae. The maggots are whitish. Host Plants : Soybean, cowpea and lablab. Nature of Damage : The female feeds on xylem of stem and lays eggs inside. The larvae further damage the stem and make a tunnel inside and fill up with excreta. The leaves and growing point dries. Broken stem can be seen in the field. ETL = 2% infested plants. Life History : The female lays the eggs in stem pith after girdling it. Incubation period 4-5 days, larval period 34 - 47 days. The pupal period 8-11 days in larval tunnels. Over winter in full grown larva within the feeding tunnel. Pest Management : 1) Collect and destroy infested plants. 2) Apply phorate granule @ 10 kg/ha or carbofuran granules 30 kg/ha at the time of sowing or spray endosulfan, dimethoate or quinalphos at 0.05%.
2. Stem Fly : Ophiomyia phaseoli Coq.; Melanagromyza sojae; Agrocmyzidae : Diptera Marks of Identification : The maggots are small and white coloured while the adults are tiny black fly. Host Plants : Beans and peas. Nature of Damage : The damage is caused by maggots causing swollen petioles. The maggot feed inside the stem and produce long slits in the stem. If cut open the stem, tunnel may be seen. The insects attack right from two-leaf stage of crop and the damaged plants dry up. ETL = 2 % infested plants. Life History : Female fly lay eggs on upper surface of leaf near petiole singly. Incubation period 3-4 days, larval period 8-10 days pupal period 5-6 days. Pupation takes place inside the stem. Total life cycle takes 2-3 weeks. Pest Management : Similar to Girdle beetle.
3. Tobacco Leaf Eating Caterpillar : Spodoptera litura F.; Noctuidae : Lepidoptera (Refer the polyphagous pests, Page No………). Minor Pests : 4. Hairy Caterpillar : Spilosoma obliqua Walk.; Arctiidae : Lepidoptera 5. Aphids : Aphis spp.; Aphididae : Hemiptera. 6. Thrips : Thrips Tabaci Lind.; Thripidae : Thysanoptera. 7. Jassids : Apheliona maculosa; Jassidae : Hemiptera. 8. White Fly : Bemsia tabaci G.; Aleyrodidae : Hemiptera.
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It is a vector of virus MBYMV (Mung bean yellow mosaic virus).
V) PESTS OF CASTOR : Castor crop is infested by the following pests : Major Pests : 1. Castor Semilooper : Achoea janata Linn.; Noctuidae : Lepidoptera. Economic Importance : It is the most destructive pest of castor reported from almost all states of the country wherever this crop is cultivated. Marks of Identification : Adult moth-stoutly built, forewings brown, hind wings dark with a white band in the middle and 3-4 white spots at the anal marging. Body length 60-65 mm. Larva semilooper, grey or black with red or whitish side stripes, 60-70 mm in length. Host Plants : Larval host : castor, pomegranate, rose, cotton etc. Adult host : citrus, pomegranate, mango etc. Nature of Damage : Larva feeds voraciously on leaves usually from the lower side. In case of severe infestation, leaves are completely skeletonized. The adult moth do not cause damage to castor. Moth damages the fruits of above mentioned host plants. Life History : Eggs – are laid on lower surface of leaves. Incubation period 3-4 days. Larva : larval period 2 weeks. Pupa : pupation in dried leaves. Pupal period 11-27 days. Life cycle completed in 4-6 weeks. Generations 5 to 6 in a year. Management Practices : Spraying with 0.05% endosulfan or carbary 50 WDP 0.2 % or quinalphos 0.05% as soon as incidence is noticed. Practical Guideline : Draw the figures of adult moth and larval stage of pest.
2. Castor Capsul Borer : Conogethes:(=Dichocrocis)punctiferalis G.; Pyralidae : Lepidoptera. Economic Importance : It is also important pest of castor found all over the State of Maharashtra. Damage to the capsule to the extent of 23 % has been recorded. Marks of Identification : Moth – small, bright yellow with numerous black spots. Larva small, 24 mm in length, brownish with pink tinge. Host Plants : Castor, guava and pomegranate. Nature of Damage : Larvae bore into the shoots and capsules and destroy them. Life History : Eggs are laid on tender shoots and capsules. Incubation period 6-7 days. Larva : larval period 12-16 days. Pupa : pupation in stem or capsules. Pupal period 7-10 days. Life cycle completed in 25-30 days. Management Practices : 1. Removal and destruction of infested shoots and capsules. 2. Spraying 0.1% malathion or 0.2% carbaryl 50 WDP. Practical Guideline : Draw the figure of adult stage of this pest.
3. Castor Jassids : Empoasca flavescens P.; Cicadellidae : Hemiptera Nature of Damage : Both nymphs and adults suck the cell sap from lower surface of leaves. As a result, margins of leaf turn pale initially, later on becoming yellowish and ultimately dry. In case of severe infestation leaves curl badly and show brown necrotic patches. Management Practices : Spraying with 0.02% fenthion / thiometon / phosalone / quinalphos / 0.1 % carbaryl as soon as incidence is noticed. Practical Guideline : Draw the figures of nymph and adult of this pest. In addition to the pests mentioned above, Serpentine leaf miner (Liriomyza trifolii) leaf eating caterpillars (Spodoptera litura) and hairy caterpillars (Spilosoma obliqua and Euproctis fraterna) are also found to infest the crop. These are described under tobacco and groundnut.
VI) PESTS OF MUSTARD :
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Major Pests : 1. Mustard Sawfly : Athalia lugens (Klug); Tenthredinidae ; Hymenoptera. Economic Importance : The mustard sawfly is widely distributed in the Indian Sub-continent. Marks of Identification : The larva is dark green and have 8 pairs of abdominal prolegs. There are five black stripes on the back and the body has wrinkled appearance. A full grown larva measures 16- 18 mm in length. The adults are small orange yellow insects with black marking on the body and have smoky wings with black veins. Host Plants : It feeds on various cruciferous plants like mustard, rapeseed, cabbage, cauliflower, knol- knol, turnip, radish, etc. Nature of Damage : Damage is done by larvae. They bites into leaves preferring the young growth and skeletonize the leaves completely. Life History : The flies lay the eggs singly by making slits in the leaves. The eggs hatch in 4-8 days. The larvae are full grown by 16-35 days. Pupation takes place in soil. The pupal period is 11-31 days. The life cycle is completed in 31-34 days. Seasonal Occurrence : October to March. Carry Over : Pupal cocoons in the ground during summer. Management Practices : 1. Collection and destruction of larvae. 2. Spraying of quinalphos or endosulfan or malathion at 0.05%
2. Mustard Aphid : Lipaphis erysimi K.; Aphididae : Hemiptera. Economic Importance : The mustard aphid is worldwide and is serious pest of cruciferous oilseeds. Marks of Identification : The nymphs and adults are louse like, pale greenish insects. They are seen feeding in large numbers, often covering the entire surface of flower- buds, shoots, pods etc. Host Plants : Mustard, cabbage, cauliflower, knol-knol, etc. Nature of Damage : Both the nymphs and adults suck cell-sap from leaves, stems, inflorescence or the developing pods. The leaves look curly, flower fail to form pods and the developing pods do not produce healthy seeds affecting adversely on yield. Life History : The pest breeds parthenogenetically and the female gives birth to 26-133 nymphs. Life cycle completed in 7-10 days. About 45 generations are completed in a year. Seasonal Occurrence : This insect is most abundant from December to March. Carry Over : Through stray plants of cabbage, cruciferous weeds etc. Pest Management : 1. Early sowing of crop preferably upto third week of October. 2. Spraying of methyl demeton or dimethoate or quinalphos at 0.03% or malathion or endosulfan 0.05%. 3. Predators of aphids are ladybird beetles (Coccinella septumpunctata) and Chrysoperla carnea.
Minor Pests : 1. Painted Bug : Bagrada spp. ; Pentatomidae : Hemiptera.
VII) PESTS OF SUNFLOWER : The crop is attacked by number of pests but are of minor importance in the State. These pests are described under other crops. 1. American bollworm : Helicoverpa armigera Hub. 2. Tobacco caterpillar : Spodoptera litura 3. Hairy caterprillar : Spilosoma spp. 4. Jassids : Amrasca biguttula 5. Aphids : Aphis gossypii 6. White Fly : Bemisia tabaci.
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Exercise No. 8 STUDIES ON PESTS OF PULSE CROPS
Material : Preserved specimens and affected plant parts. I) PESTS OF GRAM : Major Pests : 1. Gram Pod Borer : Helicoverpa armigera Hub.; Noctuidae : Lepidoptera. (Described under Polyphagous Pests Page No………..)
II) PESTS OF TUR (RED GRAM OR PIGEONPEA) : 1. Tur Plume Moth or Pod Caterpillar : Exelastis atomosa Wal. Pterophoridae ; Lepidoptera. Economic Importance : It is a common pest on pods of red gram causing considerable losses. It is a specific pest of tur in many parts of India. Marks of Identification : Moth – slender, 12 mm in length, grey coloured with long narrow wings. Forewings cut into two parts and the hindwings into three parts with fringe like border. Caterpillar 12 mm long, greenish brown, fringed with short hairs and spines. Host Plants : Tur and wal. Nature of Damage : The caterpillar makes a hole into the pod opposite to seed developing inside and then insert it’s head into the pod and feeds on the developing seed. When one seed is finished, the larva cuts another hole opposite to another seed and damage the seed. The larvae also feed on flower buds. Life History : Eggs are laid on tender shoots, leaves, flowers or pods. Incubation period 5 days. Larva : larval period 4 weeks. Pupa : pupation on pod surface or in pod burrows. Pupal period 2 weeks. Adult period is 1 to 2 weeks. Life cycle : completed within 7 weeks. Practical Guideline : Draw the figures of adults and caterpillar of this pest.
2. Tur Pod Fly : Melanagromyza obtusa Mall.; Agromyzidae : Diptera. Economic Importance : This pest is considered to be one of the important pests of tur as it is widely distributed throughout India, causing 80% loss in yield of seed. Marks of Identification : Adult flies – small, black fly. Maggot – creamy white, 4.00 mm in length. Host Plants : Tur, soybean and cowpea. Nature of Damage : The maggots after hatching from the eggs enter into the soft seeds and feed on them. At first the damage resembles to that of leaf miner as their galleries run just under the epidermis of seed. Later, they burrow deep down resulting in decaying of the grain, which become unfit for either consumption or germination. In severe cases of damage, the pods present twisted appearance. Life History : Eggs – about 38 eggs are laid in pods by a female with the help of ovipositor. Incubation period 3 – 4 days. Larva : larval period 6-21 days. Pupa : pupation in larval burrows inside the pod, pupal period 1-4 weeks. Adult – live for 5 to 12 days. Life cycle completed in 3 weeks. Seasonal occurrence : Adult flies are noticed in October and there are 2 – 3 broods on tur until harvest. Development of pest slows down during winter.
3. Pod Borer : H. armigera Hub. Noctuidae:Lepideptora (Described under Polyphagous Pests Page No……) 4. Spotted Pod Borer Or Maruca : Maruca vitreta G.; Pyralidae : Lepidoptera Economic Importance : This pest is wide-spread in tropical and sub-tropical regions of the world.
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Marks of Identification : The moth has a white cross band on the dark brown forewings and a dark border on the white hind wings. The larva is green with a brown head, short dark hairs and black wrats on the body. Host Plants : It is an important pest of pigeonpea, cowpea, green gram, black gram, soybean etc. Nature of Damage : The lara webs together the flowers and feed on them and also bore into pods and feed on the seeds resulting in appreciable loss in yield of seeds. Life History : The eggs are laid singly in the flowers or buds or on the pods of the host plants. Pupation takes place in the plant debris on the surface of ground. The total life cycle is completed within 4 to 6 weeks. Incubation period : 6 – 8 days, Larval period : 2 – 4 weeks, Pupal period 1-2 weeks.
5. Tur Pod Bug : Clavigralla gibbosa S.; Coreidae : Hemiptera. Marks of Identification : Adult bugs are greenish brown, 20 mm long, femurs swollen at aphical end, nymphs are reddish. Host Plants : Tur and Wal. Nature of Damage : Both nymphs and adults suck the sap from the pod and cause infested pod to shrivel. The pest however, become rarely serious. Life History : Eggs are laid on pods, leaves, buds in cluster. The incubation period is 8 days, nymphal period is 17 days, the adult period is 2 to 3 weeks. Total life cycle is about 4-6 weeks. Management Practices : (Pod borer complex including above pests) 1) Collection and destruction of infested pods along with caterpillars during early stage of infestation. 2) Application of pesticide at initiation of flowering with NSKE 5% or 0.05% endosulfan/ phenthoate/ phosalone or 0.04% quinalphos/ monocrotophos or dusting with quinalphos 1.5 D/methyl parathion 2 D @ 20 kg/ha. For H. armigera, first spray of HaNPV @ 250 L.E./ha use of pheromone traps, tricho cards in addition to above measures. Practical Guideline : Draw the figures of above pest.
III) PESTS OF PEA : 1. Pea pod borer : Helicoverpa armigera Hub.; Noctuidae : Lepidoptera (Described under Polyphagous Pests Page No………..). Practical Guideline : Draw the figure of larva and adult of this pest.
2. Pea Aphids : Aphis craccivora Koch. and Macrosiphum pisi K.; Aphididae : Hemiptera. (Described under groundnut page No……).
3. Pulse Beetle : Callosobruchus chinensis Lin.; Bruchidae : Coleoptera Marks of Identification : Adults are 3-4 mm in length, oval, chocolate or reddish brown in colour, larva is creamy white. Host Plants : In field – Pea, tur, gram, cowpea, lablab etc. The infestation may, however, originate in the field and be carried into the store. Nature of Damage : It is a major pest of pulses in storage. However, field infestation is also common. The young grubs burrow into the pods and feed on developing seed/grain. The holes seen on the pulses are the exit holes from where the adults have emerged. Such grains are unsuitable for sowing. Life History : Eggs are laid on surface of grains. Incubation period 5 days, larval period 30-50 days. Pupation takes place inside the infested grain. Pupal period 5-8 days. Life cycle is completed within 45 days. Management Practices : Spraying with 0.05% malathion or endosulfan 0.05%.
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Practical Guideline : Draw the figure of adult beetle.
4. Cutworm : Agrotis ipsilon Hufn.; Noctuidae : Lepidoptera. This pest is described under Polyphagous Pests, Page No………. . In addition to the pests mentioned above, leaf miner and thrips are also found to infest the crop but are of very minor importance in the State.
IV) PESTS OF MUG : (Green Gram), Udid (Black Gram), Chavali (Cowpea) & Wal: 1. Aphid : Aphis craccivora Koch.; Aphididae : Hemiptera. The pest is described under Groundnut, Page No………. .
Minor Pests : 1. Leaf Miner : Liriomyza spp.; Agromyzidae : Diptera 2. Leaf Eating Caterpillar : Spodoptera exigua Hub.; Noctuidae : Lepidoptera. 3. Pod Borer : Helicoverpa armigera Hub.; Noctuidae : Lepidoptera.
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Exercise No. 9 STUDIES ON PESTS OF FORAGE CROPS
I) PESTS OF LUCERNE : Major Pests : 1. Cut Worm : Agrotis spinifera Hub. ; Noctuidae : Lepidoptera. (Refer Polyphagous Pests Page No………..) 2. Army Worm : Mythimna separata Walk.; Noctuidae : Lepidoptera. (Refer Polyphagous Pests Page No………..) 3. Tobacco Caterpillar : Spodoptera exigua Hub; S. mauritia G. Noctuidae : Lepidoptera. (Refer Polyphagous Pests Page No………..) 4. Gram Pod Borer : Helicoverpa armigera Hub.; Noctuidae : Lepidoptera. (Refer Polyphagous Pests Page No………..) 5. Leaf Roller or Leaf Miner : Aproaerema modicella D. Gelechidae : Lepidoptera. (Refer Pests of Groundnut, Page No………..) 6. Red Hairy Caterpillars : Amsacta lineola Fab.; A. moorei; Arctiidae : Lepidoptera. Marks of Identification : The full grown caterpillar is about 25 mm long, with reddish brown to olive green in colour and the body is covered with numerous long hairs. The moths are stoutly built and have white wings with black spots. Host Plants : Maize, jowar, lucerne, cowpea, mung etc. Nature of Damage : The young caterpillars feed on growing points gregariously scrap the leaf surface, the older larvae feed voraciously and defoliate the plant. Life History : The female lays eggs in clusters on the under surface of leaf. Incubation period 2-3 days. The caterpillars complete their development in 15-23 days. Pupation takes place in soil. Pupal period is 12-15 days or during adverse condition remains in hibernation for pretty longer period. In general, the life cycle is completed in 23-55 days. The pest is more active from June to end of August. Management Practices : 1) Use of light traps. 2) Collection of larvae at their gregarious stage of feeding alongwith infested leaves and their destruction. 3) Spraying of NSKE 5%. 7. Aphids : Aphis craccivora Koch.; Aphididae : Hemiptera. (Refer the pests of groundnut page No. ………). 8. Stem Fly : Ophiomyia phaseoli Trayon.: Agromyzidae : Diptera (Refer the pests of Soybean page No. ………).
II) PESTS OF MAIZE AND SORGHUM : Major Pests : 1. Stem Borer : Chilo partellus S.; Pyralidae : Lepidoptera. (Refer Pests of Sorghum Page No………..) 2. Shoot Fly : Atherigona soccata Rond; Anthomyidae : Diptera. (Refer the Pests of Sorghum Page No………..)
Minor Pests :
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3. Leaf Roller : Marasmia trapezalis Guen.; Pyralidae : Lepidoptera. 4. Termites : Odontotermes obesus Ram.; Termitidae : Isoptera 5. Delphacid : Perigrinus maidis A.; Delphacidae : Hemiptera. 6. Aphids : Aphis sacchari; Aphididae : Hemiptera.
III) PESTS OF PASTURES : Grasshoppers : (Acrididae : Orthoptera ) : Different species of grasshoppers infest the pastures and causes major damage. They should be managed by different mechanical and biological control measures.
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Exercise No. 10 STUDIES ON PESTS OF STORED GRAINS AND GRAIN PRODUCTS
Material : Preserved insect specimens and damaged grain commodities. A) PRIMARY PESTS : Capable of causing damage to sound grains. I. Internal Feeders : The larvae feed entirely within the kernels or grains or stored material. 1. Rice Weevil : Sitophilus oryzae Linn.; Curculionidae : Coleoptera. 2. Granary Weevil : Sitophilus granarius Linn.; Curculionidae : Coleoptera 3. Lesser Grain Borer : Rhizopertha dominica Fab.; Bostrychidae : Coleoptera 4. Pulse Beetle : Callosobruchus chinensis Linn.; Bruchidae : Coleoptera. 5. Angoumois Grain Moth : Sitotroga cerealella Oliv.; Gelechidae : Lepidoptera
II. External Feeders : Larvae and adults feed on grains from outside. 6. Khapra Beetle : Trogoderma granarium Everts; Dermestidae : Coleoptera 7. Indian Meal Moth : Plodia interpunctella Hubm.; Phycitidae : Lepidoptera 8. Rice Moth : Corcyra cephalonica St.; Galleridae : Lepidoptera 9. Fig Moth : Ephestia (Cadra) cautella Walk.; Phycitidae : Lepidoptera
B) SECONDARY PESTS: Feeds on broken grains or milled products. 10. Rust Red Flour Beetle : Tribolium castaneum Herb.; Tenebrionidae : Coleoptera. 11. Saw Toothed Grain Beetle : Oryzaephilus surinamensis Linn.; Cucujidae: Coleoptera 12. Long Headed Flour Beetle : Latheticus oryzae W.; Tenebrionidae : Coleoptera. 13. Flat Grain Beetle : Laemophloeus minutus Oliver; Cucujidae : Coleoptera 14. Cadelle or Yellow Meal Worm : Tenebrioides mauritanicus Linn. Ostomatidae : Coleoptera. C) NON-INSECT PESTS : 15. Mites: Tyroglyphus spp.; Acarus siro Linn.; Acaridae: Acarina (Class : Arachinida) 16. Rats: Rattus rattus Linn.; R. norvegicus B.; Muridae : Rodentia (Class : Mammalia) A) PRIMARY PESTS : Internal feeders. 1. Rice Weevil : Sitophilus oryzae Linn.; Curculionidae : Coleoptera Economic Importance : It is cosmopolitan and polyphagous species and found to cause considerable damage to rice. Besides rice, it also cause damage to several other cereals and their products. Marks of Identification : Adult : Tiny weevil, 3 mm in length with a head produced into a snout like structure. Body reddish brown to dark brown or almost black in colour. Fore wings with four light reddish or yellowish spots. The insect is able to fly. Grubs : whitish, often found inside kernels, small and legless. Nature of Damage : Both adults and larvae feed on the sound grains of wheat, rice, maize, jowar, barely, bajri, etc. as a result, they are rendered unfit for human consumption. The adult damage a small portion of grain and feeds on inner content. Though the grains are mostly damaged in storage, the infestation is carried from the field also. Life History : Eggs : The adult female make holes in the soft portion of the grain with the help of its mount parts and lays eggs singly. Each female can lay 350-400 eggs during her life time. The incubation period is about 4 days. Larva : The grub stage lasts for 19 to 34 days. Pupa : The pupation inside the grain and the pupal period 3 to 6 days. Life cycle completed within 26-28 days. 43
2. Granary Weevil : Sitophilus granarius Linn.; Curculionidae : Coleoptera Economic Importance : It is also an important pest of cereals having been reported from most of the countries of the world. However, it is reported to be relatively less important in tropical compared to the temperate ones. Marks of Identification : Adult : Small, reddish, brown to dark brown weevil, 3.5 mm in length. It resembles rice weevil so closely that it is difficult to distinguish. However, it is larger than rice weevil, uniformly brown with smooth elytra and larger punctures on thorax. It is incapable of flight and as such its infestation in restricted to granaries only. Nature of Damage : Both grubs and adults cause damage to grains as in case of rice weevil. Life History : Similar to that of Sitophilus oryzae.
3. Lesser Grain Borer : Rhizopertha dominica Fab.; Bostrychidae : Coleoptera Economic Importance : It is considered to be second in importance to rice weevil. It is a major pest of most of the cereals. Though usually the attack is noticed in storage, the infestation is carried from field also. Marks of Identification : Adult- slender, cylindrical and small in size (3 mm) with dark brown or black colour, elytra with slightly roughed surface. Head is turned somewhat downwards, so that it is scarcely visible from above. Larva : dirty white and has a light brown head. It’s body is clothed with tiny hairs. Nature of Damage : Both beetles and larvae cause serious damage in warm climate, attacking variety of grains like wheat, rice, jowar, bajri, maize, pulses, paddy etc. They completely hollow out the grain kernels and only the bran coat is left. The grub stage can feed inside the grain or on flour or on grains destroyed by adults. Life History : Eggs : A single female can lay 300 to 500 eggs, droping them singly or in clusters in loose among the grains or sometimes on wall, on bags or in crevices in godowns. Eggs small, whitish. Larva : grubs after hatching from the eggs crawl actively about the grains, feeding on the flour produced by boring of the beetles or bore directly into slightly damaged grains. The larval period about 44 days. Pupa : The pupation is either inside or outside the grain. Pupal period lasts for about 7 days. Life cycle is completed within 2 months.
4. Pulse Beetle : Callosobruchus chinensis Linn.; Bruchidae : Coleoptera. Marks of Identification : Adult small 3-4 mm in length, oval, chocolate or reddish brown, active with long serrate antennae, brownish grey, elevated ivory like spots near the middle of dorsal side, elyctra do not cover the abdomen completely. Larva is creamy white. Nature of Damage : It is a major pest of pulses like mug, gram, tur, bean, masor and udid and causes heavy damage during monsoon season. Though the pest attack is commonly noticed in storage, the infestation sometimes is carried from the field where the eggs are laid on green pods. The young grub burrows into the pod or grain, feed on inner contents and pupate inside the grain and later emerges as an adult through the exit hole prepared by the full grown grub before pupation. Life History : Eggs : Incubation period - 5 days. Larva : Larval period 30-50 days. Pupa : Pupal period 5-8 days. Life cycle completed in 45 days.
5. Angoumois Grain Moth : Sitotroga cerealella Oliv.; Gelechidae : Lepidoptera Marks of Identification : Moth – small, dirty yellowish brown with wings completely folded over black in a sloping manner, with long fring of hairs at anal margin of hind wing. Larva 15 mm, whitish. Nature of Damage : Larvae feed on the endosperm of grain leaving other part untouched. The damage to the grain is not noticed until full grown larva bores hole for moth to escape. Hole is circular with characteristic ‘flap’ or ‘trap door’ The infested grains are hollowed out by the larvae and filled up by the excreta and webbing. 44
Life History : The eggs are laid on grains or near grains singly or in batches. Egg period is 4-8 days. Larval period 3 weeks. Pupation takes place in the cavities of grain. Pupal period 1 to 2 weeks. Life cycle completed within 50-55 days.
II. External Feeders : 6. Khapra Beetle : Trogoderma granarium E.; Dermestidae : Coleoptera Economic Importance : It is a cosmopolitan species and observed to thrive well under climatic conditions where temperature ranges between 92° F to 110° F. In the Indian Union it has been reported as one of the most destructive pests from all the States. Though it is a serious pest of wheat, it is found to attack other cereals like rice, oat, maize, jowar etc. Marks of Identification : Adult : About 2-3 mm long, convex, oval in shape with grey and light brown markings and emerginate eyes. Grubs – brownish white in colour, 4 mm long and body covered with long reddish brown hairs, which are usually directed backward and form a sort of thick tail at the anal end. Nature of Damage : The infestation generally occurs at superficial layers of grains as they are not able to penetrate beyond certain depth. However, in case of heavy infestation, it may destroy the entire lot. Only larvae are harmful, usually feed voraciously on embryo of grains thus adversely affecting their germination but can destroy the entire grains. Adults are harmless. Life History : Eggs : A female lays about 125 eggs, loosely among the grains in her life time. They hatch in 6 to 26 days. Larva : Larvae become full grown in about 50 days. Pupation : on the surface of grain in bulk or edges of bags. The pupal stage lasts for 6 to 17 days. The adults are ready for egg laying in 2 to 3 days after emergence and live for 10 to 32 days. Under unfavourable conditions of climate and shortage of food the larval period may be prolonged upto 200 days or even upto 4 years.
7. Indian Meal Moth : Plodia interpunctella Hubm.; Phycitidae : Lepidoptera Economic Importance : The pest is cosmopolitan in distribution and feeds on a variety of food articles and grains. It is a major pest of wheat. Marks of Identification : The moth : wing expanse of 12 mm to 18 mm, the forewings lustrous brown with yellowish or whitish bands across the basal half. Larva : greyish white in colour, 23 mm long when full grown. It’s body is covered with fine hairs and the skin is granular. Nature of Damage : The larva feeds on germ portion of wheat. During the process, tubular webbing is formed by it either on bags or on the bulk of the food material. In serious cases the bag or flooring is completely covered with silken sheets. Life History : Eggs : A female lays on an average 200 eggs singly or in groups on the food material. The egg and larval periods lasts for 5 to 7 and 30-40 days respectively. Pupa : Pupation takes place inside the silken cocoons attached to he bags or sometimes naked. The pupal period is 12 to 25 days. An adult lives for 2 to 25 days. Generation completed in about 60 days.
8. Rice Moth : Corcyra cephalonica Staint.; Galleridae : Lepidoptera Economic Importance : The pest occurs in almost all the parts of the world. It is considered to be one of the most destructive pests of stored paddy, rice and other cereals in many parts of India. Besides cereals, legumes, oil cakes, dried fruits, suji, atta, etc. are also damaged by this insect. Marks of Identification : Moth : pale greyish brown in colour with a wing expanse of about 12 mm. Larva : Creamy white in colour with a prominent broad, yellowish head, 25 mm when full grown. Nature of Damage : Larva alone feeds under silken webs on broken grains but later instar can attack sound grains. Life History : Eggs : Female lays about 90-200 eggs on bags, walls of godown etc. The egg is white, oval or elliptical in shape. Incubation period lasts for about 5 days. Larva : The larval period lasts
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for 15 to 40 days Pupa : Pupation takes place inside the silken galleries. The pupal period 12 to 15 days. An adult lives for 4 to 6 days. Life cycle completed in 50 days.
9. Fig Moth : Ephestia cautella W.; Phycitidae : Lepidoptera Marks of Identification : Moth – small, wings dirty white to greyish with black bands. Nature of Damage : The larva feeds on dried fruits such as dried apples, dates, berries, fig and so also cereals and their products. The caterpillars web together the grains and feed on them. Life History : The female lays whitis eggs in cracks and crevices of the receptacles or on the food stuff. Incubation period 8-12 days. Larval period 40-50 days. Larva pupates inside the cocoon in infested material. Pupal state lasts for 12 days. Life cycle is completed in about 2 months.
B) SECONDARY PESTS : 10. Rust Red Flour Beetle : Tribolium castaneum H.; Tenebrionidae : Coleoptera Marks of Identification : Beetle small, 3-4 mm, oblong, flat, brown in colour. Nature of Damage : Both the larva and adult feeds on grains which are already broken or damaged. The pest is more damaging to milled cereals, like atta, maida, suji which become mouldy and emit a pungent smell. It is secondary pest of all grains and primary pest of flour and other milled products. In grains, embryo or germs portion is preferred. Life History : The female lays eggs in the flour or frassy material among the grains and other food stuff. The incubation period lasts 4-10 days. Larval period 22-25 days. Pupation takes place in the flour. Pupal stage lasts 5-9 days. Life cycle completed in 26-30 days. 11. Saw Toothed Grain Beetle : Oryzaephilus surinamensis L.; Cucujidae: Coleoptera Marks of Identification : Beetle narrow, flattened, thorax having six teeth like serrations on each side. Nature of Damage : The larva feeds mostly on flour, ‘maida’ or the grain dust produced by the infestation of other primary pests. The damaged grains are attacked by the adults. Excessive infestation of the pest on the food products makes them unpalatable and unsalable.
12. Long Headed Flour Beetle : Latheticus oryzae W. ; Tenebrionidae : Coleoptera. Marks of Identification : Beetle small, light brown with elongated body, head is longer. Nature of Damage : It is an important pest of milled products. Beetles feed on grains damaged by the primary pests. Both larvae and adults feed on cereal flours, and rice products.
13. Flat Grain Beetle : Laemophloeus minutus O. ; Cucujidae : Coleoptera Marks of Identification : Smallest amongst the stored grain insect pests, 1.5 – 2.0 mm, light to dark reddish brown. Nature of Damage : It prefers broken and powdered grains as a food. The larva feeds mostly on wheat embryo and on account of scavenging habits adult feeds on grains spoiled by primary pests.
14. Cigarette Beetle / Tobacco Beetle : Lasioderma serricorne Fabr.; Anobiidae : Coleoptera. Marks of Identification : Rounded, light brown, 3-4 mm beetle. Hosts : Tobacco products. Nature of Damage : Larva and beetle bore hole to the tobacco product and feed within it. Life History : Eggs are laid on surface of produce. Life cycle completes within 4-6 week.
C) NON-INSECT PESTS : 15. Mites : 1) Tyroglyphus spp.; 2) Acarus siro Linn.; Acaridae : Acarina
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(Class : Arachnida) Marks of Identification : Very small, pale, straw to dark reddish brown. Nature of Damage : It is an important pest of mills. The mites are reported to damage germ portions of wheat and when present in large number, they promote sweating, impart objectionable smell to the gains. Besides, they also cause damage due to their feeding.
16. Rats : 1) Rattus rattus Linn.; 2) R. norvegicus B.; Muridae : Rodentia (Class : Mammalia) Economic Importance : Annually 2.5% losses are caused due to rodents in storage. As it is responsible for plague, it is considered as the most expensive rat of India. Nature of Damage : Rats cause heavy damage to stored grains. The daily consumption of a rat is about 10 g of grains apart from other damage and 100 rats excluding their progeny can damage about one tonne of grains in a year.
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Exercise No. 11 STUDIES ON MANAGEMENT OF STORED GRAIN PESTS
Sources of Infestation : Following are the main source of infestation. a) Field Infestation : Pests like pulse beetle, rice weevil, grain moth etc. lay eggs on grains or pods in the field. The infestation is noticed in the grains when they are stored in stores. b) Cross Infestation : Through old bags, godown, trucks, bullock carts etc. when godown or bags are empty then pests may remain in cracks, crevices of godown, on bags etc and when they get food supply can multiply. The measures adopted for the control of stored grain pests are of two types : I) Preventive : Measures which are employed to protect fresh stock of grains from the attack of pests. II) Curative : Measures employed to control the pests when infestation noticed in the grains. I) Preventive Measure : 1. Sundrying : Threshing yard should be away from granaries and should be clean. It is very essential to reduce moisture content of grains. When the grain has moisture content below 8% most of the insect spp. do not survive/ multiply. The grains are dried by spreading a thin layer in the sun heat. Dryers are also used now a days. 2. Mixing of Inert Dust For Seed Purpose : This method is used by many farmers in villages. The inert dust such as clay, ash etc causes physical injuires to insect. The dust causes laceration on the cuticle, resulting in desiccation and death of the insect. 3. Bagging : When grains are properly dried and ready for storage it should be bagged in gunnies free from pest infestation. As far as possible use new bags. But when it is not possible, the old bags should be fumigated or treat them with 0.1 % malathion or DDVP to avoid cross infestation. 4. Godown Hygiene : Before storing the grains in bags in godown. i) All the cracks, crevices, hole existing in the floor should be closed with cement. ii) All dirt, rubbish, webbing should be removed from the store and destroyed, iii) All the rat burrows should be closed with cement iv) It should be white washed v) Before storing grains, the godown should be disinfected by spraying malathion 0.1%. 5. Care While Storing : Proper storage is also necessary to protect grains from moisture damage which usually occurs at the bottom layers of bags due to seepage of water from the floor. Wooden crate dunnage is necessary. It helps free circulation of air, and prevent losses due to moisture accumulation. 6. Proper stocking of bags is necessary to facilitate the inspection and treatment of grains. II) Curative Measures : Most practicable and useful curative method is the fumigation. Fumigation may be defined as the treatment of commodity or a space with a gaseous material to kill the insect pest present. They are highly volatile and able to penetrate deep and kill insect within a large mass of food stuff. In case of small scale storage, first to sieve the grains and remove different stages of pests. But in large scale storage, it is not possible to sieve and clean the grains and hence direct fumigation has to be carried out. Fumigation is possible only under air tight conditions. For small scale fumigation Metal bins or ‘Kothis’ can be made air tight. For large scale fumigation, however, the dump method is used.
Dump Method of Fumigation : The grains are enveloped in air proof cover. The covers for dump method are prepared from balloon fabrics or rubberised cloth or polythene sheet of varying sizes. The standard size of cover being 20’ x 15’ which can accommodate about 500 bags at a time. Put the cover over the grains to be fumigated and the sides touching the ground are covered with dry earth to prevent the leakage. The fumigant should be introduced (poured) from the opening at the top which should subsequently be closed. After the expiry of exposure time, the cover should be gradually opened from the sides so that the operator should not exposed to the fumes for a longer 48
period. The bags should not be disturbed for at least 24 hours to allow the enclosed gases to escape. After which the grains can safely be used. The grains required to be stored for longer period should at least be fumigated three times in a year. One after winter, second before monsoon and third at the end of monsoon. The commonly used fumigants for grains storage are given in the table along with the rate, time of exposure and the precautions to be taken while using particular fumigant.
Cntd…...
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Optimum Doses of Pesticides Recommended by the Storage and Research Division of Ministry of Food .
Sr. Name of the Dose of pesticide Method of Against Remarks No pesticide application . 1. Malathion 0.1% Spray on grain As prophylactic Forthightly 50% EC bags, walls, floors treatment spraying. etc. Should not be against insect sprayed on food pests. grains directly. 2 Ethylene 3 ml/quintal for small The ampules are As fumigant 7 days exposure Dibromide storage 22 gms/cu.m. for inserted in storage against insect period. (EDB) large storage. structures after pests (except for breaking and oilseeds/ flour) making the structure airtight. 3. EDCT 30-40 kg per 100 cu. m. in Fumigation in As fumigant 7 days exposure mixture large scale storage. For airtight condition against insect period. small storage 55 ml. per on bags/ in bulk. pests (except for qtl. oilseeds/flour) 4. Alluminium a) 2-3 tablets of 3 gms / For fumigation of For insect 7 days exposure phosphide metric tonne. grains in bag/bulk control period, should be b) Amorphos powder 50% storage under done by trained 10 g pkt /metric tonne. sufficient airtight person under, c) 2 tablets of 0.5 gms per condition. sufficient air tight rat live burrow. 2 tablets of 0.5 gms condition. each are inserted in living burrow and --- the burrows are For field rat sealed with mud. control 5. Zinc Preparation of bait : Pure Mix them For House, Field Application after phosphide zinc phosphide:2 parts. thoroughly and Rat control prebaiting. Food grains as base: 96 place in paper parts. cones Any edible oil:2 parts. 6. Anticoagulant I part rodenticide + 19 The four For control of Continuous s (Rodafarin, parts bait material. constituents are house rats. baiting for 10-15 warfarin, For 500 gms bait : mixed thoroughly days. Ratafin etc.) i) Flour (cereals/ millets) and prepared bait 450 gms. material is kept in ii)Any edible oil : 10 gms. shallow vessel at iii)Sugar or places visited by jaggary:15gms. rats. iv)Anticoagulant: 25gms.
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Exercise No.12. STUDIES ON PESTS OF BRINJAL
Material : Preserved pests specimens and affected plant parts. Major pests : 1. Brinjal Shoot and Fruit Borer:Leucinodes orbanalis Guen.; Pyralidae: Lepidoptera Economic Importance : It is one of the most serious pests of brinjal fruits and plants. Long and narrow fruits are less susceptible to attack. 21% fruits are found damaged by this pest. Marks of Identification : Moth : Medium size, the forewings are whitish with large black and brown patches and dots all over. Caterpillar: Small, light pink in colour. Host Plants : Polyphagous brinjal, potato, bitter gourd, pea pods, cucurbits etc. Nature of Damage : Infestation starts few weeks after transplanting. The caterpillars bore into the growing shoots, midribs and petioles of large leaves and feed on internal tissues. As a result of damage, affected shoots wither and dry up and plants exhibit the symptoms of drooping. After fruit formation, larvae makes their entry under the calyx, when they are young. The holes, later plugged with excreta leaving no visible sign of infestation. Large circular holes seen on the fruits are the exit holes. Such fruits loose market value and are unfit for human consumption. Life History: Eggs: 250, laid singly on ventral side of leaves, shoots, flower buds or sometimes on fruits, I.P.: 3-5 days in summer and 7 days in winter. Larva : L.P. : 12-15 days in summer and 22 days in winter. Pupa: Pupation in boat shaped cocoons on plant. P.P.7-10 days. Adult: Life span : 2-3 days. The pest is active throughout the year. Management Practices : 1. Continuous cropping of brinjal and potato should be avoided. 2. Removal and destruction of affected shoots and fruits alongwith larvae. 3. Nursery treatment : Soil application of phorate 10 G @ 70 g/m2 at the time of sowing. 4. Spray with 0.05% monocrotophos or 0.2% carbaryl or dusting 10% carbaryl dust @ 20 kg/ha. 3-4 weeks after transplanting and second application 15 days thereafter controls the pest effectively or NSKE 5%. 5. Use of sex pheromone traps with leucinolure.
2. Jassids : Amarasca bigututtula Ishida. The pest is discussed under potato. 3. Aphids : M. persicae Sulz. The pest is discussed under potato. 4. White fly : Bemisia tabaci Genn.; Bemisia argentifolii Belows; Aleyrodidae : Hemiptera Economic Importance : It is serious pest of brinjal now a days. Marks of Identification : Adult : Fly is small, delicate insect with yellow body and haylineings dusted with waxy powder. Nymphs : Is small, sluggish and pale yellow, oval in shape. Host Plants: Polyphagous, feeds on brinjal, cotton, okra, potato, cabbage, cauliflower, tomato, melon and some weeds. Nature of Damage: Both nymphs and adults suck the cell sap from the underside of the leaves. In case of severe infestation the vitality of the plant is lowered and vegetative growth is checked. This result in shedding of flower buds and fruits. The insects also excretes honey dew on the leaves which encourages the development of black sooty mould, adversely affecting the photosynthesis. The attacked crop gives sickly appearance. Besides, the pest is known to transmit virus diseases in many crops. Life History : Eggs : 119, laid singly on the underside of leaves. I.P. : 3-5 days in summer and 5-33 days in winter. Nymphs : N.P. 9-14 days in summer and 17-81 days in winter. Pupa : P.P. : 2-8 days,
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Pupation : On Leaves. Adult: Fly longevity: 2-5 days in summer and 24 days in winter. Life cycle: Completed in 14-122 days. No. of generations 10-12/year Management Practices: Spray the crop with 0.1% methyl dematon or 0.05% triazophos /monocrotophos /dimethoate/ fenpropathrin as soon as incidence is noticed.
5. Mites : Tetranychus telarius L.; Tetranychidae : Acarina; Ref. Pests of grapevine. Nature of Damage : They are found in large colonies on underside of leaves covered with fine silky webs. As a result of their feeding, white specks appear on leaves. These later enlarge and leaf become discoloured and dries away. Management Practices : Spray with 0.2% sulphur or dicofol 0.03% control the mites effectively.
Minor pests : 6. Leaf roller : Antoba olivacea M.; Pyralidae : Lepidoptera
7. Epilachna beetle : Epilachna spp.; Coccinellidae : Coleoptera. The pest is described under cucurbits.
8. Tingid Bug (Brinjal lace wing) : Urentius spp.; Tingidae : Hemiptera.
9. Root-knot Nematode: Meloidogyne spp.; Heteroderidae : Tylenchida; It is described under Tomato (Page No. ….).
10. Grey weevil (Ash weevil): Myllocerus spp.; Curculionidae : Coleoptera.
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Exercise No.13 STUDIES ON PESTS OF TOMATO AND BHENDI (OKRA)
Material : Preserved pest specimens and affected plant parts. I) PESTS OF TOMATO : 1. Fruit Borer : Helicoverpa amigera (Hub.); Noctuidae : Lepidoptera Economic Importance : It is a major pest of tomato, widely distributed in the tropics, subtropics and warmer temperature region of the world. It is a serious pest of gram and tur. Marks of Identification : Moth : Medium sized stout, light yellowish brown. Forewing are pale brown with a dark brown circular spot in the center. Hindwings are pale smokywhite with a blackish outer border. Caterpillar : 3 to 5 cm long, greenish with dark broken grey lines along the sides of the body. Host Plants : Highly polyphagous pest damaging crops like cotton, gram, tomato, peas, sunflower, bean, pigeon pea etc. Nature of Damage: On hatching, young larvae feed on tender foliage. Full grown larvae attack the fruits. They bore circular holes and thrust only a part of their body inside the fruits and eat the inner contents. If the fruit is bigger in size, it is only partly damaged by the caterpillar but latter it is invariably invaded by fungi and bacteria and spoiled completely. The larvae move from one fruit to another and a single caterpillar may damage and destroy 2 to 8 fruits. Life History : Eggs – female lays 200 eggs singly on tender parts of the plant. Incubation period 6-7 days. Larva –larval period 2 weeks. Life cycle completed in 5-6 weeks. Several generations in a year. Management Practices : 1. In early stage of attack, handpicking of caterpillars and their destruction help in reducing the intensity of infestation. 2. Ploughing the field after harvest of the crop would expose the pupae which would be destroyed by birds. 3. Use of Trichogramma chelonus 50000 eggs/ha. 4. Spraying the crop with 0.05% quinalphos or fenitrothion, HaNPV 250 LE, NSKE 5%. 2. Cutworm : Agrotis ypsilon Rott.; Noctuidae : Lepidoptera Described under polyphagous pests page no. …….. . 3. Leaf Eating Caterpillar: Spodoptera litura Fab.; Noctuidae : Lepidoptera; Described under polyphagous pests page no. …….. . 4. White Fly : Bemisia tabaci Gen.; B. argentifolii Below; Aleyrodidae : Hemiptera; Pest has been described under Brinjal page no. ……. . 5. Serpentine Leaf Miner : Liriomyza trifolii Burg.; Agromyziae : Diptera This American serpentine leaf miner has entered in India with severe incidence in Maharashtra, Karnataka, A.P., Gujarat etc. Economic Importance : L. trifolii which is known as American serpentine leaf miner due to its origine from Southern United States of America and spread to other countries during 1970. It entered in India along with plant material during 1990-91 and spread to the different states. Marks of Identification : Adult fly : 1.5 - 2.0 mm long, grayish black with yellow spot on top of thorax and has plum red eyes. Larva : Legless, orange yellow, about 2 mm long. Host Plants : Polyphagous pests feeding on different vegetable, ornamental, fibre and pulse crops. Nature of Damage: Maggots feed in between two layers of leaf on mesophyle making narrow serpentine mine that appears whitish when seen from upper surface, ultimately causing blotches and holes. Life History : Eggs : Laid singly in small incisions in the leaf with ovipositor. Pupation takes place in soil.
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Management Practices : Monitoring the presence of flies by yellow sticky traps and spray crop with insecticides like NSKE 5%, monocrotophos 0.05%, cypermethrin 0.01%. Assignment : Describe the IPM Programme for tomato crop.
6. Root-Knot Nematode : Meloidogyne incognita; Heteroderidae : Tylenchida. Economic Importance : It causes severe damage to the crops like tomato, brinjal, bitter gourd, okra, bottle gourd, pomegranate, grape vine etc. Marks of Identification : Full grown female is microscopic, lemon shaped and 0.5 to 0.7 mm long 0.3 to 0.5 mm broad. While the juveniles (larvae) and the males are thread like and full grown males are about 1 mm long. Host Plants : Highly polyphagous, non-insect pest damaging different vegetable and fruit crops as well as pulses, ornamental and flower plants. Nature of Damage : After hatching the juveniles (larvae) enters into the roots and feed within the roots by sucking cell sap. This is endoparasitic nematode causing formation of root galls. It affect adversely on the absorption of nutrition by the roots and hence the symptoms like stunting growth, yellowing and wilting of the plants is observed. The damage by this nematode also encourages the root-rot disease. Life History : The females lay the eggs on surface of feeder roots in masses in gelatine matrix. The life cycle is completed within 3-5 weeks depending on climatic conditions. Management Practices : A) Cultural methods : 1) Summer follow and ploughing, 2) Crop rotation with non-host plants, 3) Soil solarization before sowing seed of vegetable crops, 4) Intercropping by sowing the crops like tagetes, sunnhemp, mustard, fenugreek etc., 5) Application of F.Y.M., organic amendments oil cakes like neemcake, caranj kake etc. @ 2 t/ha., 6) Discoiuraging the planting seedlings of vegetables or fruit crops from nematode infested fields. B) Biological control: Use of fungal biopesticidal formulations comprising Trichoderma and paecalomyces. C) Chemical Control : Application of granular insecticides like carbofuran 3G or phorate 10G @ 1 to 2 kg a.i./ha for vegetables and other seasonal crops and 4 kg a.i./ha for grown-up fruit crops.
Minor Pests : 7. Mealy bugs: Ferrisia virgata Ckll.; Phenococcus solanapsi; Pseudococcidae : Hemiptera. 8. Aphids : Aphids gossypii G.; Myzus persicae S. 9. Leaf hopers : Amrasca biguttula biguttula Ishida. 10. Thrips : Thrips tabaci Lind.; Caliothrpis indicus B. 11. Mites : Teranychus spp – Red spider mite; Aceria spp. – Eiophied mite
II) PESTS OF OKRA (BHENDI) : Major Pests : 1. Shoot & fruit borer: Earias vitella Fab.; E. insulana Boised; Arctiidae : Lepidoptera. Economic Importance : Serious pest of bhendi and cotton. Marks of Identification : Moth : E. vitella – moths having small pale white fore wings with broad greenish band in the middle. E. insulana : the forewings are completely greenish. Caterpillars of both species are brownish white with number of black and brown spots on the body and hence also called spotted bollworm. Larval length is 18 mm. Host Plants : Cotton, Okra, ambadi, holly hock and several other malvaceous plants. Nature of Damage : Caterpillars bore into the tender shoots, flower buds and fruits. As a result, the shoots dry, flower buds and fruits drop prematurely. Fruits remaining on the plants get deformed and often show exit holes of the larvae.
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Life History : Eggs : 60-432, laid on tender shoots, flower buds and young fruits, I.P. 3-7 days. Larva : L.P. 9-11 days in summer and 20 days in winter. Pupa: Pupation in the tough silken cocoons either on plant or in soil or among the fallen leaves and rubbish. P.P. 5-7 days in summer and 8-9 days in winter. Life cycle: Completed in 3 weeks in summer and 4 weeks in winter and there are 12 generations in a year. Management Practices : 1. Removal and destruction of infested shoots, fruits and shed material helps in reducing the intensity of infestation. 2. Spraying with 0.2% carbaryl or 0.1% malathion or 0.06% endosulfan or 0.01% cypermethrin/fenvalerate, profenophos 0.05%. 3. Use of T. chelonis @ 4 to 5 trichocards/ha.
2. Jassids : A. biguttula biguttula Ishida; Described under potato.
3. Aphids : Aphis gossypii Glover; Myzus persicae S. Describe under Potato
4. White fly : Bemisia tabaci G.; The adults of white fly are also responsible for transmitting the virus disease ‘Yellow vein mosaic’. Described under Brinjal (page no. ………) .
5. Mites : Tetranychus spp.; Described under brinjal (page no. ………).
6. Root knot nematode : Meloidogyne spp.; Described under pests of tomato (page no. ………).
Minor Pests :
7. Leaf roller : Sylepta derogata Fb.
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Exercise No.14 STUDIES ON PESTS OF CRUCIFEROUS VEGETABLES
Material : Preserved pest specimens and affected plant parts. Major Pests : 1. Diamond back moth : Plutella xylostella L.; Plutellidae : Lepidoptera. Economic Importance : It is one of the serious pests of cruciferous crops throughout the world. It is cosmopolitan in distribution. Marks of Identification : Moth : Small, brownish grey in colour, have three pale whitish triangular spots on their hind margins of forewings which form a diamond pattern when the insect is at rest with wings folded along the body. Hence, the name “diamond back moth”. Caterpillar : Small, greenish, smooth with some scattered hairs and tapering at both the ends. Host Plants : Cabbage, cauliflower, knolkhol, mustard, radish, etc. Nature of Damage : Young larvae feed on epidermis of leaves while full grown larvae bore inside the heads. Round transparent patches appear on leaves due to feeding. In case of sever infestation the plants may be completely skelotonized. Life History : Eggs : 57, singly along the veins on lower surface of leaves at night. I.P. : 7 days. Larva : L.P. 2 weeks. Pupa : Pupation on the leaves in thin silken cocoons, P.P.: 1 week. No. of generations : 5-7 /year. Pest is active throughout the winter season. Management Practices: 1. Spraying with 0.05% malathion or quinalphs or fenitrothion control the pest effectively. 2. Spraying with Bt (Bacillus thuringiensis) @ 1 to 1.5 kg/ha, Abamectin 1.8 EC 0.001%. 3. Spraying with 4% NSKE. It is necessary to add wetting and spreading agent viz; teepol / sandovit @ 1 ml/lit. 4. Trap cropping with mustard, the crop attracts 80-90 % moths for colonization. 5. Tomato, when intercropped with cabbage reduces egg laying by diamond back moth.
2. Mustard sawfly : Athalia proxima Klug.; Tenthredinidae : Hymenoptera. Economic Importance : Most destructive pest of cruciferous crops and is especially serious on raddish and mustard. Marks of Identification : Adult : Flies are small, black in colour, with wings having black veins. They have two pairs of wings. Larva : Small, black and smooth, have a tendency to curl up and drop on the ground when disturbed Host Plants : Cabbage, cauliflower, knolkhol, mustard, raddish and turnip. Nature of Damage: Larvae feed on leaves from margin inward, mostly during morning and evening. They cut small holes into the leaves and skeletonize the plant. Frequently large number of larvae can be found on each leaf. Life History : Eggs : 30-35, singly in the leaf tissues on the lower surface close to the margins with the help of saw like ovipositor. I.P.: 4-6 days. Larva: L.P. -2 weeks. Pupa: Pupation in soil in earthen cocoons. P.P.: 10-12 days. Adult : Lives for 3-5 days. The pest remain active throughout the year except April and May in which remain in aestivation. The peak period of activity is during Sept. to Dec. after which the activity declines.
Management Practices : 1. Hand picking of larvae. 2. Spray with 0.05% malathion or 0.1% carbaryl or endosulfan 0.05% controls the pest effectively.
3. Cabbage butterfly : Pieris brassicae Linn.; Pieridae : Lepidoptera
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Economic Importance : Very common and regular pest of cruciferous crops and having wide range of host plants. Marks of Identification : The butterflies have pale white or snow white wings and smoky shade on the dorsal side of body. The young larvae are pale yellow and become greenish yellow later on. Host Plants : Cabbage, cauliflower, knol-knol, turnip, radish and other cruciferous crops. Nature of Damage: The first instars caterpillars just scrap the leaf surface, whereas the subsequent instars eat up leaves from the margins inwards, leaving intact the main veins. Life History : The butterflies lay on an average 164 yellowish conical eggs in clusters of 50-90 on the upper or lower side of leaves. The egg hatch in 11-17 days in winter and 3-7 days in summer. The larval period is of 15-40 days while the pupal stage lasts for 7 to 28 days depending upon climatic conditions. The butterflies live for 3-13 days. Management Practices : 1. Hand picking and mechanical destruction of larvae during early stage of damage. 2. Spraying of 0.2% carbaryl or 0.05 % malathion or endosulfan.
4. Aphids : Brevicoryne brassicae Linn.; Aphididae : Hemiptera. Economic Importance : It cause considerable damage in case of severe infestation. Marks of Identification : Adult aphids are very small, soft bodied insects, yellowish green in colour. They have cornicles on abdomen. Host Plants : Cruiferous crops, brinjal, potato, chillies, tomato, shepu, sunhemp, sweet potato, chakwat, geranium, fennel etc. Nature of Damage : Nymphs and adults suck the cell sap from lower surface of leaves. Their continuous feeding lead to general yellowing of leaves and subsequent drying. Besides, the pest excrete sugary substance which spread on leaf surface and attract the black fungus, that hampers the photosynthetic activities of plant. Life History: Only female are noticed in Maharashtra State. They reproduce parthenogenetically and single female produces 12-24 young ones (nymphs). The nymphs become mature within 7-9 days and start reproducing. Management Practices: Nursery spray with 0.04% endosulfan/ 0.03% dimethoate / 0.05% malathion. Field application with 0.05% malathion as soon as infestation noticed. Minor Pests : 5. Leaf miner : Liriomyza brassicae R.; Agromyzidae : Diptera 6. Flea beetles : Phyllotreta cruciferae G.; Chrysomelidae : Coleoptera. 7. Painted bug : Bagrada cruciferarum K.; Pentatomidae : Hemiptera. 8. Tobacco leaf eating caterpillar : Spodoptera litura; Noctuidae : Lepidoptera.
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Exercise No.15 STUDIES ON PESTS OF CUCURBITS
Material : Preserved pest specimens and affected plant parts. Major Pests : 1. Fruit Fly: Bactrocera cucurbitae C. (Melon fruit fly); B. dorsalis H. (Oriental fruit fly); Trypetidae : Diptera. Economic Importance : These are cosmopolitan species causing huge annual losses to several vegetable and fruit crops. More than 50% fruits are damaged by fruit flies. Among the various species, B. cucurbitae is most common and destructive on vegetables. Marks of Identification : Adult fly : Resemble common house fly but has conical, yellowish brown abdomen and transparent wings with grey spots and bands. Maggot : Small, direty white, legless, tapering at one end. Host Plants : Gourds, melons, tondali, guava, mango, ber and other fruits. Nature of Damage : Maggots feed on pulp of the fruits. Infested fruits start rotting and rendered them unfit for human consumption. Life History : Eggs : 200, laid just under the skin (epidermis) of the fruits, I.P. : 3-5 days. Larva : L.P. : 2- 3 weeks. Pupa : Pupation in soil. P.P.8-10 days. These species breed almost throughout the year except winter during which they hibernate as pupae or adults. During rainy season the activity of melon fruit fly is at its peak while heavy rain stop breeding of fruit fly. Management Practices : 1. Clean cultivation – Removal and destruction of fallen fruits and infested fruits daily to minimize the intensity. 2. Use of Rakshak traps with methyl eugenol as attractant. 3. Deep ploughing to expose hibernating stages. 4. Application of spray bait containing 20 ml malathion + 200g jaggry + 20 lit. of water. 5. Spraying with 0.05% malathion or 0.2% carbaryl at flowering reduce the intensity of infestation.
2. Pumpkin beetles : Red Pumpkin beetle : Raphidopalpa foveicollis L.; Black pumpkin beetle : R. intermedia J. Yellow pumpkin beetle : Ceratia cincta F. Chrysomelidae : Coleoptera. Economic Importance : The red pumpkin beetle is the most destructive species, damage the young seedling and kill the same. Marks of Identification : Adults : Small, the elytra of red pumpkin beetle is pale orange yellow to deep pale brown while in case of black pumpkin beetle, it is black and it is yellowish in yellow pumpkin beetle. Grub : Small, slender, elongate, creamy yellow with brown head and legs. Host Plants : All cucurbits. Bottle gourd, red pumpkin and cucumber are heavily damaged by red pumpkin beetle. Nature of Damage : Beetles are mainly responsible for the damage of the plant above ground. They damage the leaves, flowers and fruits making irregular holes and causing death or retardation of growth. Incase of heavy infestation resowing is also required to be done. The grub live in the soil and feed on roots and stem of the plant. Fruits and leaves also get damaged when comes in contact with the soil. Damaged roots, stems start rooting. Life History : Eggs : 150-300, laid in moist soil to a depth of 2.5 cm, near the plant. I.P.:5-27 days depending on temp. and moisture content of soil. Larva : L.P. 12-34 days. Pupa : Pupation in soil. P.P. : 15-35 days. Adult : Live for 20-197 days. Life cycle : Completed in 52-270 days. The maximum activity of the pest is observed during hot weather, (Mar.-May), reaching its peak in middle of April. 58
Management Practices : 1. Preventive measures-burning of old creepers, ploughing and harrowing of field after harvest of the crops to destroy the stages of the pest. 2. Collection and destruction of beetles in early stage of infestation. 3. Spraying with 0.05% malathion or dusting with 5% malathion dust @ 10 kg/ha gives satisfactory control of the pest.
3. Blister beetle : Mylabris pustulata Th.; Lytta spp.; Meloidae : Coleoptera. Economic Importance : Major pest causing considerable damage. Marks of Identification : Beetles : Medium sized, having 3 black and 3 yellowish orange bands running vertically and alternately on elytra. When disturbed these beetles exude an acidic yellow fluid which contains cantharidin and causes blisters on human skin and hence the common name. Host Plants : Polyphagous, infesting cucurbits, cotton, groundnut, millets, rose and okra. Nature of Damage : Beetles feed on pollens and petals of flowers and flower buds as a result fruit setting is adversely affected. Life History : Life cycle : Life cycle has not been fully worked out. Eggs : Laid in soil I.P. : 14-15 days. Grubs : Found in soil and feed on egg pods of grasshoppers and locusts. Pupa : Pupation in soil. Hibernation takes place in pupal stage in soil. Adult : Emerges out of soil around August and are active till early December. Management Practices : 1. Hand collection and prompt destruction of beetles keep the population under check during early morning hours, when beetles are less active. 2. Spraying with 0.05% malathion or dusting with malathion 5D or endosulfan 4D @ 20 kg/ha.
4. Serpentine leaf miner : Liriomyza trifolii Burg.; Agromyzidae : Diptera; (Refer the pests of tomato page no. ……… ).
5. Epilachna Beetle or Hadda Beetle: Epilachna dodecastigma M.; E. vigintioctopunctata Fab.; Coccinellidae : Coleoptera. Economic Importance : E. vigintioctopunctata is the most common and destructive species. Marks of Identification : Beetles : Spherical, pale brown and mottled with black spots. E. dodecastigma has 6 spots on each elytra, while E. vigintioctopunctata has 14 spots on each elytra. They are strong flier. Grubs : Yellow with hairs on their body. Host Plants : Cucurbits, brinjal, potato, tomato, etc. Nature of Damage : Both grubs and beetles feed by scrapping chlorophyll from epidermal layers of leaves, which get skeletonized and gradually dry away. Life History : Eggs : 120 to 180, laid in masses on ventral surface of leaves. I.P. : 2-4 days. Larva : L.P. 12-18 days. Pupa : Pupation on leaves p.p. 3-6 days. Life cycle : Completed in 18-25 days in summer and may extend upto 50 days in winter. No. of generations 7/year. Management Practices : 1. Hand picking of grubs and collection of beetles by hand nets during early stage of attack helps in reducing the intensity of infestation. 2. Spray with 0.05% endosulfan / malathion / quinolphos.
6. Root-knot nemato : Meloidogyne spp.; Heteroderidae : Tylenchida (Refer the pests of tomato , page No. ………….).
Minor Pests : Aphids, jassids and mites also found to infest the crop and have been described under potato and brinjal. 59
7. White Fly : Bemisia tabaci Gen.; Aleyrodidae : Hemiptera. (Refer the pests of tomato, page No. ………….).
8. Thrips : Thrips tabaci Lind.; (Refer the pests of chilli, page No. ………….).
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Exercise No.16 STUDIES ON PESTS OF POTATO AND SWEET POTATO
I) PESTS OF POTATO : Material : Preserved pests specimens and damaged plant part. The crop is damaged by several pests in the field and in storage. The tuber moth assumes serious forms causing huge losses. Major pests : 1. Tuber moth : Phthoromaea operculella Zeller; Gelechidae : Lepidoptera Economic Importance : It is a cosmopolitan pest found in warmer countries throughout the world. Marks of Identification : Moth : Small, narrow winged and greysh brown. It is nocturnal in habit. Caterpillars : Small, pinkish – White or pale greenish, with dark brown head. Host Plants: The caterpillars are reported to feed on leaves of potato, brinjal, tobacco and tomato in field, but potato tubers under storage are most vulnerable to its attack. Nature of Damage: In early stage of the crop growth the pest is injurious to plant as leaf miner. It also bores into petioles and terminal shoots. The main danger is to tubers both in the field and under storage. The caterpillars bore the tubers and feed on the pulp. As a result, potato tubers rot. The presence of black excreta near the eyebuds help to detect its presence in the tubers. On cutting such tubers, one can find the larva in the pulp. Life History : Eggs : 150-200 eggs are laid singly near the eyebuds of exposed tubers or sometimes on underside of leaves. Incubation period 3-6 days. Larva: Larval period 2-3 weeks. Pupa : Pupation in soil, in earthen cacoons. Pupal period 7-10 days. Life cycle : Total period about 4 weeks. No. of generation : 8-9 / year. Management Practices : In field : 1. Timely earthing up of the crop to cover the exposed tubers helps in reducing the intensity of infestation. 2. Spray with 0.05% endosulfan or quinalphos or 0.1% carbaryl at 60 days after planting. 3. Heaps of harvested potatoes should not be kept exposed in the field but covered with straw and the infested tubers should be rejected before storage. 4. Release of egg-larval parasitoid, Copidsoma koehleri B. @ 20,000 mummies/ha at 7 days interval starting 45 days after planting or release of egg larval parasitoid Chelonus blackburni @ 60,000 adults/ha in 4 releases at weekly interval found to reduce infestation by 50-55%. In Storage: 1. The potatoes should be stored in well ventilated cool and dry places, with temp. not exceeding 21°C. 2. Covering of tubers with 2-3 cm layer of dry sand in heap is highly effective remedy against the pest. 3. Fumigate the tubers with CS2 @ 1 kg/27 cu.m. for 48 hrs at 70°F. or methyl bromide @ 1kg/27 cu.m. for 3 hrs before storage. CS2 is reported to induce sprouting in storage. 4. Walls of godown should be sprayed with 0.15% carbaryl at an interval of three months. 5. Treatment of seed potato tubers with 5% malathion dust @ 125 g/100kg is reported to offer good protection against the pest. Such treated potatoes however, should not be used for consumption. 6. If cold storage facilities are available, the produce can be safely stored for a longer period. 7. Release of egg-larval parasitoid, C. koehleri B @ 500 pairs/quintal or C. blackburni @ 200 adults/quintal tubers in storage, helps in reducing the intensity of infestation. 8. Application of Bt powder @ 100 g/quintal tubers in storage also found effective in reducing the infestation of pest.
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2. Cutworm : Agrotis ypsilon Root; Noctuidae : Lepidoptera. (Already described under polyphagous pests, Page No…….)
3. Aphids : Myzus persicae Sulzer; Aphididae : Hemiptera Marks of Identification : Adult : Oblong, tiny, yellowish, soft, bodied insect with two projections called cornicles on dorsal side of the abdomen. Host Plants: Polyphagous : Potato, brinjal, cabbage, raddish, chilli, tomato, tobacco, sunhemp, sweet potato etc. Nature of Damage : They are found in large number on underside of leaves and tender shoots. The nymphs and adults suck the cell sap as a result affected leaves turn yellow, get wrinkled and distorted. The aphids also exude honedews on which a fungus develops and rapidly covers the plant with sooty mould that interferes with photosynthetic activity of plant. The growth of the plant is stunted and the yield is adversely affected. Besides, they transmit various virus disease such as “leaf curl”, mosaic and veinal necrosis and cause severe loss. Life History : Alate and apterous forms reproduce parthenogenetically. Single female produces 8-22 nymphs/day. The nymphs undergo 4 moults. A generation is completed in 7-9 days and several generations are completed in a season. Management Practices : Spray with 0.05% endosulfan or 0.03% dimathoate control the pest effectively.
4. Jassids : Amrasca biguttuala Ishida; Jassidae : Hemiptera Economic Importance: It is predominant pest. Heavy infestation results in considerable reduction of tuber formation. Marks of Identification : Adults : Greenish yellow with front wings having a black spot on each at the apical margin and two black spots on the vertex of the head. Nymphs : are also green. They walk diagonally. Host Plants : Potato, binrjal, bhendi, cotton and other malvacious plants. Nature of damage : Both nymphs and adult suck the cell sap from the lower surface of leaves. The damaged leaves curl updwards along the margins, turn yellowish, then brown and show burnt of patches which adversely affect the growth and yield. Life History: Eggs : Whitsh eggs are laid singly in leaf tissues along the veins. I.P. 1 week. Nymphs: N.P. 1-2 week (moult 5 times). Life cycle: completed in a period of 1 month. Management Practices : Spray with 0.05% endosulfan, 0.03 % dimethoate control the pest effectively.
Minor pests : 5. Epilachna beetle Or Hadda beetle: Epilachna dodecastigma M.; Coccinelidae: Coleopteran; Described under Cucurbits. 6. Thrips : Hercothrips indicus B.; Thripidae : Thysanoptera 7. Mites : Hemitarsonemus latus Banks.; Tetranychidae : Acarina.
II) PESTS OF SWEET POTATO : Major pest : 1. Sweet potato leaf eating caterpillar or Sphinx caterpillar : Agrius convolvuli L.; Sphingidae : Lepidopetra Economic Importance : It occasionally assumes serious form and causes economic loss. Marks of Identification : Moth : Stout, pale grey coloured with black pointed head. The abdomen has pink and white lateral bands. Caterpillar : Dark brown with reddish patches on sides and sharp curved horn-like process at tail end, about 7.5-10 cm long. Host Plants: Sweet potato, mug, udid, and til. 62
Nature of Damage: Caterpillars feed on leaves voraciously. In case of severe infestation defoliate the plant. Life History : Eggs: seed like, laid singly on leaves. I.P. 5-10 days. Larva : L.P. 2-3 weeks. Pupa : Pupation in the soil, P.P. 7-11 days. The pest hibernate in pupal stage. Life cycle : Completed in 4- 15 weeks. S.O. Pest is active in monsoon. Management Practices : 1. Hand picking and destruction of caterpillars in early stage of infestation. 2. Ploughing the field after harvest will expose the pupae. 3. Dusting the crop with 10% carbaryl dust or methyl parathion 2% @ 20 kg/ha or Spraying of carbaryl 50 WDP 0.1%.
2. Sweet potato weevil : Cylas formicarius Fb.; Curculionidae : Coleoptera. Economic Importance : Serious pest of sweet potato, loss of tubers to the extent of 60-70 % has been reported. Marks of Identification : Adult weevil : Small, ant-like, steel black in colour with brown elongated snout like head. Grub: small, legless and pale yellow in colour. Host Plants: Sweet potato only. Nature of Damage:The grub infest vines (stems) and cause tunneling inside. The grubs as well as adults bore into tubers, both in field and godowns, feed on inner content and spoil them. Dark black patches are noticed on the tubers and stems. Life History : Eggs : 100-200, on the tubers and stems of vines by making small cavities. I.P. : 5-10 days Larva : L.P. 2-3 weeks. Pupa : Pupation in the larval burrows in vines. P.P. 7 days. Adult : Male longevity 10-15 weeks and female longevity 13-16 weeks. Life cycle : Completed in 4-5 weeks. Carry over : Pest is carried from one field to another through the infested vines and from season to season by breeding in tubers left over after harvest. Management Practices: 1. Healthy cuttings should be selected for planting. 2. After harvest of the crop vines should be collected and destroyed. 3. Follow proper crop rotation. 4. Spray with 0.1% carbaryl. 5. Apply phorate 10 G in the soil at planting @ 10 kg/ha.
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Exercise No.17 STUDIES ON PESTS OF SPICES AND CONDIMENTS (CHILLI, ONION, GARLIC, PEPPER, TURMERIC AND GINGER)
Material : Preserved pest specimens and affected plant parts. I) PESTS OF CHILLI : Major pests : 1. Thrips: i)Scirtothrips dorsalis Hood. ii)Thrips tabici Lind.; Thripidae : Thysanoptera. Economic Importance : In case of severe infestation 30-50% crop may lost. Also responsible for transmitting ‘leaf curl’ disease. Marks of Identification : Adult : Minut, delicate insect less than 1 mm long and yellow in colour. Wings are fringed with hairs. Nymphs : More minute and wingless. Host Plants : Polyphagous: onion, chilli, brinjal, bhendi, cotton, mango, tondali, bottle gourd, guava. Nature of damage : The thrips scrap the epidermis of leaves and suck the oozing sap. The damaged plant tissues initially become whitish, later brown and ultimately dry. As a result, leaves curl and become small. Such symptoms locally known as “Murda” or “Bokadya”. Life History : Both sexual and parthenogenetic reproduction occur. Eggs : Female lays 50-60 fertilized or unfertilized eggs inside the leaf tissues generally on lower side of the leaf. I.P.: 4-5 days. Larva : L.P. 6-8 days. Pupa : Prepupal and pupal periods are generally found in soil at a depth of 2.5-5 cm. for 4-6 days. The pest is more active during latter part of monsoon season especially during a dry days. Management Practices : 1) Nursery treatment : Phorate 10G 70 g/m2, 2) Spraying with 0.03% endosulfan/m. demeton/ dimethoate/ 0.05% monocrotophos as soon as infestation is noticed, NSKE 5% or cypermethrin 0.01%.
2. Mites: i) Tetranychus Spp.; Polyphagotarsonemus latus Banks; Teranychidae: Acarina; Tarsonemidae : Acrina. Economic Importance : Cosmopolitan in distribution. Host Plants : Polyphagous. Nature of damage : They are found in large numbers on ventral side of leaves under a protective cover of fine webs. Both nymphs and adults suck the cell sap and devitalize the plants. Severally infested leaves show brownish patches and ultimately dry up. It also act as vector for transmitting chilli “leaf curl” or ‘murda’ disease. Management Practices : Spraying of sulphur 0.2% or dicofol 0.03%.
3. Fruit borers: Helicoverpa armigera Hubn.; Spodoptera litura Fab.; Noctuidae : Lepidoptera.; (Refer the polyphagous pests Page.No……)
Minor pests : 4. Aphids : Aphis gossypii G.; Myzus persicae Suzler; Aphididae : Hemiptera. 5. Cut worms : Agrotis ypsilon Rott.; Noctuidae : Lepidoptera. 6. Termites : Odontotermes obesus R.; Termitidae : Isoptera. 7. White fly : Bemisia tabaci G.; Aleyrodidae : Hemiptera.
II) PESTS OF ONION AND GARLIC : Onion thrips : Thrips tabaci Lind.; Thripidae : Thysanoptera. Economic Importance : Pest is cosmopolitan in distribution. Marks of Identification : Adults : Have narrow and long wings fringed heavily with fine hairs. Nymphs : Are wingless. They are minute, about 1 mm long, slender, fragile and yellowish in colour. 64
Host Plants: Highly polyphagous Besides onion, it attacks cole crops, cotton, cucurbits, chilli. Nature of Damage : Nymphs and adults found between leaf sheaths and stems lacerating the epidermis of leaves and suck the exuduing sap. The affected leaves show silvery white blotches which later become brownish and get distorted from tips downwards, wilt and ultimately dry away. Heavy infestation at seedling stage results in retardation of growth and severe scarring of leaves which ultimately kills the seedlings outright. In case of heavy infestation at later stage, the bulbs remain undersized and get distorted in shape. Life History : Eggs : 40-60 in notches in the epidermis of leaves. I.P. 8-9 days. Nymph : N.P. 4-6 days. Pupa : Pupation in soil, prepupal and pupal period lasts for 2 and 3 days respectively. Seasonal incidence : Pests is active throughout the year. It is found on onion and garlic during. Nov. to May, from these hosts it migrates to cotton and other summer crops in June & then to cole crops during Sept-Oct. A long spell of dry weather is favourable for its rapid multiplication. Management Practices: Spraying with 0.05% endosulfan/ monocrotophos / dimethoate/ malathion/ quinalphos or 0.01% cypermethrin.
Minor pests : 2. Onion fly : Delia antigua M.; Anthomyiidae : Diptera 3. Leaf eating caterpillar : Cutworm : Agrotis ypsilon Rott.; Noctuidae : Lepidoptera. 4. Tobacco caterpillar : Spodoptera litura Fab.; S. exigua Hub.; Noctuidae : Lepidoptera.
III) PESTS OF PEPPER : 1. Scales insects : Lepidosaphes piperis Gr.; Coccidae : Hemiptera Economic Importance : Severe in nurseries. Marks of Identification: Adult: Elongated, oval, dark gray in colour, Active throughout year – peak in March-June, September-November. Host Plants : Curry leaf and pepper Nature of Damage : Both nymphs and adults covers stems, leaves, petioles in large numbers. Nymphs and adults with their piericing and sucking type of mouth parts suck the sap from stem, leaves, petioles, berries. The infested vines fade, disfigure, wither and dry up. Nurseries are severely affected. Yellowing and shedding of leaves and berries. Stunted growth and death of vines/plants. Life History : The female scale insects lays the eggs under the scales and the total life cycle is completed within 4 to 6 weeks. Management Practices : 1. Prune and destroy infested twings. 2. Spraying of malathion / dimethoate 0.05% or Neonicotinoids like imidacloprid 17.85 SL @ 150 ml/ha or Thiamethoxam 70 WG @ 200 gm/ha or Calothiamidin 50 WDG @ 100 gm/ha or Thiazophos 50 WP @ 100 gm/ha.
2. Pollu beetle : Longitarsus nigripennis Mats Chrysomelidae : Coleoptera Economic Importance : The most important pest of pepper occurring regularly in the plantation. Marks of Identification : Adult – small shining, yellow and blue flea beetle. Grub-Yellowish with black head, 5 mm in length. Life History : Female beetles scoop out shallow holes on the berries – lay-100 eggs. Lay 1-2 eggs in each hole. Incubation period – 5 to 8 days. Grub – 20 to 32 days, Pupal period 6 to 7 days in earthen cells in soil. Life cycle – 39 to 50 days No. of generation-4 between July to January. Nature of Damage : The grubs bore into berry and feed on its internal content excavating it completely within 10 days. Then it moves into another berry and thus 3 to 4 berries are destroyed by a single grub before it becomes full grown in 20 to 32 days. Attached berries appear dark in colour are hallow inside and crumple when pressed such berries known locally as Pollu berries. Grub cause 65
5 to 8% damage to berries. Grub may eat into the spike stalk causing entireregion to dry up. Adults feed voraciously on tender leaves by makings holes. Management Practices : 1. Tilting the soil at the base of the vines at regular intervals to destroy pupae. 2. Application of phorate 10 G @ 10 kg/ha or fiprinil 0.3 G @ 10 kg/ha in the soil around vine base will help in destroying the grubs falling to ground to pupate.
3. Mealy bugs : Ferrisia virgata Ckll.; Pseudoccidae : Hemiptera (Refer the pests of guava.) 4. Tobacco leaf eating caterpillar (Refer the pests of tobacco) 5. Green peach aphid (Myzus persicae Sul.):Refer the pests of potato . IV) PESTS OF TURMERIC AND GINGER : Rhizome fly : Mimegralla coerruleifrons Mocquart; Micropisidae : Diptera. Economic Importance : Rhizome fly is becoming a serious menace to the cultivation of turmeric and ginger crops in recent years in Maharashtra State. Marks of Identification : Adults : Flies are large in size with slender body and long legs. The body is black in colour, transparent wings with ashy spots. Eggs : Are small, white, cigar shaped, tapering at either side. Larva: Creamy white in colour, apodous and measures 9.5 mm. in length and 1.95 mm in breadth. Host Plants : Turmeric and ginger. Nature of damage : The maggots feed on the rhizome as a result of which yellowing of plants and rotting of rhizomes takes place. Life History : Flies are noticed in fields during Aug.-Sept. Eggs : Laid singly or in cluster of 6-10 at the base of the plants under the lumps of soil, in cracks and on the surface of soil. I.P. 2-5 days. Larva : L.P. 13-18 days. Pupa : Maggots pupate in rotten rhizomes. P.P. : 10-15 days. Life cycle : Completed in 4 weeks. Management Practices : 1. Spraying with 0.05% fenitrothion or monocrotophos. 2. Soil application of phorate 10G @ 20 kg/ha or carbaryl 10 D 20 kg /ha. 3. Preventive measures : destruction of stray plants in off season, selection of healthy rhizomes for planting. 4. Removal and destruction of rotten rhizomes along with maggots from the field after harvest of crop will help to check the breeding of the pest. *************
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Exercise No.18 STUDIES ON PESTS OF AMARANTHUS
Material : Preserved specimens and damaged plant parts. Major Pests : 1. Amaranthus stem weevil : Hylolixus truncatullus (B); Curculionidae : Coleoptera. It is almost specific pest of amaranthus widely disrubuted in India and neighbouring countries. The pest attacks both wild and cultivated crops. Varieties with large leaves being comparatively more damaged than those with prominent stems. Marks of Identification : Eggs are smooth, pale yellow in colour. The grubs are stout, curled, legless, white in colour. Adults are ash-grey in colour. Host Plants : Amaranthus Nature of Damage: On hatching the grub bite their way into the stems and feed on pith region, making irregular zigzag tunnels, which are also filled with the excreta. The affected stems become weak and often split longitudinally due to transpiration and this results in excessive evaporation, the plants get desiccated and ultimately dry up completely. Life History: Oviposition : Inside stem; I.P. : 5 to 6 days. L.P.: 10 to 12 days. Pupation : In stem. P.P.: 8 to 10 days. Adult period : 12 to 66 days. Damaging State : Grubs and adults. Management Practices : 1. Remove and destroy all wild Amaranthus plants growing in the vicinity of cultivated crops. 2. Spraying the crop with 0.05% dichlorovos or malathion is effective.
2. Leaf eating caterpillar : Hymeria rucurvilis (Fabr.); Noctuidae : Lepidoptera. It is a sporadic pest of Amaranthus and is widely distributed in the Indian Subcontinent. It is also distributed in tropical and sub tropical regions, including Africa, Asia, Australia and Hawaii Islands. Marks of Identification : Eggs are very small in size, snow white in colour. Catterpillars are greenish in colour with white lines on thorax. Adults are small sized. Black coloured, slender bodied moths. Host Plants : Amaranthus, spinach, grassland and pastures. Nature of Damage : On hatching the caterpillar feed on epidermis and on tissues of leaves, later on they web together with the leaves and silken threads secreted by them and feed within. Gradually these webbed leaves become completely devoid of chlorophyll and dry up. Life History : Oviposition : Leaves preferably on top shoots. I.P.: 3 to 4 days. Larval period : 12 to 16 days, Pupation : In the soil, 7-9 days. Adult period 6 to 10 days. A life cycle completed in 3 to 4 weeks. Damaging State : Larvae. Management Practices : To control these caterpillars, spray with 0.03 % endosulfan / 0.05 % malathion or 0.1% carbaryl. Following pests infest the leafy vegetables sporadically which have been described under the pests of other crops. Cutworm, aphids, grass hoppers, termites, mustard saw fly, flea beetles, leaf miner (Liriomyza spp.) and jassids. *************
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Exercise No.19 STUDIES ON PESTS OF CORIANDER
Material : Preserved specimens and damaged plant parts. 1. Coriander Aphid : Hyadaphis coriandari (Das); Aphididae : Hemiptera. It is a common pest of coriander widely disrubuted in the world. Other important species of aphid is Myzus persicae Sul. Marks of Identification : H. coriandari has both apteraus and alate farms. The colour of the aphids are in general yellowish green dusted with grayish wax with long cornicles. M. persicae : Adult : Oblong, tiny, yellowish, soft, bodied insect with two projections called cornicles on dorsal side of the abdomen. Host Plants : H. coriandari : coriander, carrots, soybean, Bishop’s weed, fennel, etc. M. persicae : Polyphagous : Potato, brinjal, cabbage, raddish, chilli, tomato, tobacco, sunhemp, sweet potato etc. Nature of Damage: They are found in large number on underside of leaves and tender shoots. The nymphs and adults suck the cell sap as a result affected leaves turn yellow, get wrinkled and distorted. The aphids also exude honedews on which a fungus develops and rapidly covers the plant with sooty mould that interferes with photosynthetic activity of plant. The growth of the plant is stunted and the yield is adversely affected. Besides, they transmit various virus disease such as “leaf curl”, mosaic and veinal necrosis and cause severe loss. Life History: Alate and apterous forms reproduce parthenogenetically. Single female produces 8-22 nymphs/day. The nymphs undergo 4 moults. A generation is completed in 7-9 days and several generations are completed in a season. Management Practices: For vegetable purpose: 1.Use of resistant varieties, 2. Protection and encouraging the predators like ladybird beetles, green lace wing, etc. For seed purpose (Dhane) : spraying of NSKE 5% or neem oil 1% or Verticillium lecanii at 0.2% or methyl demeton /malathion / diamethoite / endosulfan at 0.05%. The stored grain pests like granary weevil, red flour bettles, pulse bettles, tobacco/cigarette beetle etc. damage the coriander seed during stoage for which refer the pest of stored grain.
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Exercise No.20 STUDIES ON PESTS OF COLOCASIA AND MORINGA
Material : Preserve specimens and damaged plant parts. I) PEST OF COLOCASIA : 1. Web worm : Hyphantria cunea ; Arctiidae : Lepidoptera Marks of Identification : The caterpillar are pale yellow to dark grey with yellow spots are observed, maximum length 35 mm. Adult is mostly white in North but in the South blank or brown spots are observed on fore wings of adult. Host Plants : Colocassia Life cycle : Eggs : The adult moth lay eggs under surface of the leaves in hair covered cluster Larval webs are progressively enlarged. Larval period is 4-6 weeks. Papa : Pupal stage is over winter in the bark. Adult : Adult is white in north but in south there may be black spot on the fore wings. It is quite hairy front legs are white yellow or bright yellow wing span of 35-42 mm. Nature of Damage : Young larva feed on upper surface of leaf. Later they consume the whole leaf causes yield loss. Management Practices : 1. Use parasitic wasps to control them. 2. Prune and destroy leaves with webs. 3. Spray BTK (Bacillus thuringiensis var. kurstaki).
II) PEST OF MORINGA : 1. Leaf eating caterpillar:Noordia blitealis W., N. moringae; Pyraustidae:Lepidoptera. Marks of Identification : The moths seen very much similar in both the species, N. moringae slightly bigger in size. Life History : A female lays as many as 232 creamy white oval eggs in cluster each cluster having 34- 96 eggs. The larva is devoid of a prothoracic shield and poses a brown head and measures 14-20 mm long pupation in soil. Nature of Damage : The larva remain in a thin silken web on the under surface of leaf and feed on the leaf lets resulting in drying of the leaves into papery structures. The whole tree become defoliated. Management Practices : 1. Collection and destruction of affected plant parts. 2. Application of malathion 0.1% is effective.
2. Aphids : Lipaphis erysimi; Aphididae : Hemiptera Hosts Plants : Moringa, colocassia and mustard Nature of Damage : Aphids draw sap from plant tissue using mouthparts modified for piercing and sucking. They feed on foliage, twings, branches, fruits etc. Some species inject the toxic saliva into plant during feeding and due to which the growth of the plant is stunted. Discolouration of the leaves and fruits. These aphids excrete the honey dew like substances on the leaves and due to which the sooty mould fungus is attracted towards them and photosynthetic activity is reduced. Life History : Wingless adult female aphids can produce 50-100 offspring, a newly brown aphid become a reproducing adult within about a week and then can be produce up to 5 offspring per day for up to 30 days.
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Management Practices : 1. Avoid excessive application of the Nitrogen fertilizer. 2. Optimum planting date. 3. Collection and destruction of the infected plant parts. 4. Spray the crop with endosulphan 0.05% or monocrotophos 0.08%.
3. Moringa stem borer : Plocaederus ferrugineous; Cerambycidae : Coleoptera. Economic Importance : This is only one common pests of moringa. Marks of Identification : Adult : Dark brown, beetle which lay egg singly under loose bark or on tree trunk. Host Plants : Moringa, cashewnut, etc. Nature of Damage : The grubs bore into the bark in their early stages and into wood in their late stages. Making extensive tunnels within chewed up wood and excreta out of the bore holes. Both young plants and older trees are attacked by the pest and are killed outnight. Life History : The beetles lay the eggs under loose bark on the trunk. The life cycle is completed in more than a month and there are several overlapping generations in a year. Pupation takes place in larval tunnels. Management Practices : 1. Swabbing the cut area of the stem and the exposed bark with carbaryl 50 WP 0.2% or lindane 20 EC 0.05%. 2. Paining coal tar + kerosene mixture (1: 2) upto one meter length of exposed trunk region on the stem. 3. Root feeding with monocrotophos 36 WSC 10 ml + 10 ml water kept in a polythene bag on one side of the tree and keep the same amount on the other side of the tree (totally 20 ml/tree) divided into two equal halves will give protection when threre is moderate incidence. In treated trees avoid plucking the moringa fruits for 30 days.
Minor pests : 4. Spodoptera : Spodoptera moriciana; Noctuidae : Lepidoptera.
5. Bark eating caterpillar : Indarbela quadrinotata W.; I. tetraonis M. Indarbellidae : lepidoptera
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Exercise No. 21 STUDIES ON PESTS OF CURRY LEAF AND TOBACCO
Material : Preserve specimens and damaged plant parts. I) PESTS OF CURRY LEAF : 1. Lemon butterfly : Papilio demoleus Linn.; Papilionidae : Lepidoptera. (Refer the pest of Citrus Page No. ). 2. Citrus psylla : Diaphorina citri K..; Psyllidae : Hemiptera. (Refer the pest of Citrus Page No. ). Minor pest: 3. Tortoise beetle: Siliana farinose
II) PESTS OF TOBACCO : 1. Tobacco leaf eating caterpillar : Spdoptera litura F.; Noctuidae : Lepidoptera. Economic Importance : The pest is cosmopolitan and polyphagous infesting various crops in the world. Marks of Identification : Adults : Moths are medium sized stout with forewings grey to dark brown in colour with wavy markings. Hindwings are whitish. Larva:Caterpillar are pale greenish brown and smooth, with yellowish green dorsal stripes and prothoracic plate. Full grown caterpillar measures 35-40 mm in length. Host Plants : Tobacco, peas, brinjal, banana etc. Nature of Damage: The caterpillars, when young, feed gregariously on leaves and juicy stems and become isolated at later stage of growth. Life History : Eggs : Laid in masses, covered with brown hairs on tender leaves I.P. 4-5 days. Larva: L.P. : 14-21 days. Pupa : Pupation in earthen cocoons. P.P.: 9-14 days. Life cycle : Completed in 13-14 days. Management Practices : 1. Collection of eggs masses and caterpillars. 2. Ploughing after harvest of the crop to destroy the pupa. 3. At the early stage of infestation, dusting with 10% carbaryl @ 20-25 kg/ha controls the pest satisfactory. 4. Spraying of SlNPV @ 250 LE. 5. Use of sex pheromone traps with spodolure.
Minor pests :
2. Stem borer : Gnorimoschema heliopa L.; Gelechidae ; Lepidoptera
3. Cut worm : Agrotis ypsilon Rott.; The pest has been discussed under polytphagous pests page no…….. .
4. White fly : Bemisia tabaci is known as vector for transmitting persistent viruses.
5. Aphid : Myzus persicae Sulz.
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Exercise No.22 STUDIES ON PESTS OF MANGO
Material : Preserved pests specimens and damaged plant parts. Major pests : 1. Mango hoppers Or Jassids: Amaritodus atkinsoni L.; Cicadellidae: Hemiptera.; Idioscopus clypealis L.; Jassidae : Hemiptera. Economic Importance : Most destructive pests, occur regularly during flowering season, and cause huge losses. Marks of Identification : Adults : Wedge shaped, small insect with greyiesh body and three dark brown spots on head. Host Plants : Polyphagous : Mango, citrus, mulberry, chikoo etc. Nature of Damage : Both nymphs and adults suck the cell sap from the young leaves, tender shoots and flower (inflorescence) due to which flowers, buds wither and die off. The damage is more pronounced in flowering season. Premature dropping of flowers and fruits occur. Also excrete honeydew, which encourages development of black sooty mould. As a result upper surface of leaves, flowers and shoots become black which affect the fruit setting. Life History : Eggs : Laid in tissues of flowers and midribs of young leaves, I.P.: 4-6 days. Nymph: N.P.: 8-13 days. Life cycle: Completed in 12-29 days. C.O.: Adult hibernates under the bark of trunk. S.O. : Pest is active during flowering season. Management Practices : First spray before flowering on bark of branch and two more sprays when buds begin to sprout with 0.04% dimethoate or 0.05% quinalphos or 0.1 % carbaryl, fenvalerate 0.01%, imidacloprid 0.0053 %
2. Mango Stem borer : Batocera rubus L.; Batocera rufomaculata (de Green) Cerambycidae : Coleoptera Economic Importance : Entire tree gets killed in case of severe infestation. Marks of Identification: Adult: Well built, conspicusously long (5-6 cm) and brownish yellow. Orange yellow spots and lateral spines on thorax, antennae longer. Larva : 8-9 cm long and have strong jaws, whitish-yellowish in colour. Host Plants : Mango, fig, rubber, mulberry etc. Nature of Damage : On hatching, the grubs make zig - zag burrows beneath the bark and tunnel into the trunks or main stem, moving upward, feeding on internal tissues. The mass of frass (refuge) gets accumulated beneath the bark or sometimes sap and masses of frass may be seen exuding from the bored hole. The branches and ultimately the tree may die. Life History : Eggs : Under loose bark, I.P. : 1-2 weeks. Larva : Grub period about 6 months. Pupa : Inside stem, P.P. 3-4 weeks. Adult : 60-100 days. No. of generation : 1/year. Management Practices: 1) Locate the grubs, remove and kill. 2) Inject borer solution (2 part CS2 + 1 part chloroform + 1 part creosote oil) or CS2 or ED/CT mixture or petrol in live borer holes with syringe and seal with mud. 3) Cut and destroy the affected branches.
3. Mango fruit-fly: Bactrocera (=Dacus) dorsalis H.; (Oriental fruit fly) Trypetidae : Diptera Economic Importance : Most destructive pest. Rotting of fruits occur. Marks of Identification : Adults : Small fly (7 mm) resembling to common housecfly. Abdomen is conical, yellowish brown, wings transparent with grey spots or bands on them. Maggot : white, small and tapers at one end. 72
Host Plants : Polyphogous – mango, guava, pomegranate, citrus, banana and several vegetable crops. (Cucurbits) Nature of Damage : Maggots bore into the fruit and feed on pulp. Infested fruits start rotting and drop down. Brown rotten patch appears on fruit. Rotting of fruits occur. Life History: Eggs : 50, under the rind of the fruit, I.P.: 2-3 days. Larva : L.P.: 1-4 weeks. Pupa : Pupation in soil, P.P. 8-10 days. C.O.: Pest hibernate in pupal stage in soil during winter. S.O. : Pest is active in June – August. Management Practices : 1) Sanitation- daily removal and destruction of fallen affected fruits. 2) Application of spray bait (20 ml. malathion + 200 g gur + 20 Lit. water). 3) Spraying the trees and adjoining hedges with 0.05% endosulfan, 0.1% carbaryl or 0.05% malathion. 4) Monitor the fruit-fly population in orchards by using methyl eugenol traps. (Rakshak trap).
4. Mango stone weevil : Sternochetus mangiferae Fab.; Curculionidae : Coleoptera. Economic Importance : Totapuri, Neelam and Alfanso varities are more susceptible. Marks of Identification : Adult : Weevil is short, stout, oval and dark, 5 to 8 mm long. Larva : Is small, thick and white. Host Plants : Mango only. Nature of Damage : Grubs bore through the pulp, enter into the stone and passes its entire life inside the stone. Adult feed on the pulp and find its way out of ripe fruit. As a result, discolouration of pulp adjacent to the stone and larval excreta is often seen when the infested mangoes are cut. There is no external sign of infestation on fruit. Life History : Eggs : In the skin of ripening fruit. (Epicarp) Pupa : Pupation inside the stone. The generation : Is completed in 40-50 days. Only one generation in a year. C.O. Adult weevil remain inactive from July-August onwards, hiding in soil or underneath the bark of trees until next season. Management Practices : 1) Spraying the trunks with kerosene oil emulsion after harvest to kill the adults. 2) Spraying on young fruits with 0.1 % malathion. 3) Destruction of affected fruits. 4) Digging of soil to expose the hibernating weevil.
5. Mealy bugs: Drosicha mangiferae Green. ; Pseudococcidae: Hemiptera. Economic Importance : Sometimes cause severe damage to mango. Marks of Identification : Bugs are flat, oval waxy-whitish insects. Female wingless while males have brownish black wings. Host Plants : Jack fruit, guava, papaya, mango, citrus, jamun, etc. Nature of Damage : The nymphs and adult females suck the cell-sap from flowers, developing fruits and shoots. Excrete honey dew on which sooty mould develops, affecting adversely on photosynthesis. The flowers and developing fruits drop-off. Life History : Eggs : The eggs are deposited in soil during April – May and hatch in December – January. Male : 67-119 days; Female : 77-135 days.
Management Practices : 1) Ploughing below the tree to expose eggs. 2) Soil application of 2% methyl parathion dust to kill newly emerged nymphs. 3) Use of sticky bands to prevent the climbing on trees (Sticky substance or greasy band) half meter above ground in second week of December or use of 30 cm alkathene sheet banding around the stem of mango. 4) Spray with 0.04 % monocrotophos or Verticillium lecanii 0.2%. 73
5) Use of predator Cryptolaemus montrouzieri.
6. Bark eating caterpillar: Indarbela quadrinotata W.; I. tetraonis M. Inderbellidae : Lepidoptera (The details of this pest are given under citrus.)
7. Mites : Oligonychus mangiferus R and S.; Tetranychidae : Acarina (Refer polyphagous pests.)
Minor pests :
8. Scale insects : White mango scale : Aulacaspis tubercularis N.; Diaspidae : Hemiptra. Coconut scale : Aspidiotus destructor Sign.; Coccidae : Hemiptera.
9. Leaf gall insects : Allasomyia tenuispatha K.; Cynipidae : Diptera
10. Shoot borer : Chlumetia transversa WIK.; Noctuidae : Lepidoptera.
11. Red Ants : Oecophylla smaragdina Fab.; Formicidae : Hymenoptera.
Other Minor pests : Thrips Leaf eating caterpillar Mango psyllids Termites
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Exercise No.23 STUDIES ON PESTS OF CITRUS
Material : Preserved pests specimens and damaged plant parts. Major pests : 1. Lemon butterfly: Papilio demoleus Linn.; Papilionidae : Lepidoptera Economic Importance : It causes severe damage to citrus particularly in nurseries. Marks of Identification : Butterfly : Have yellow and black markings on wings. Larva : Green colour and measures 38 mm, when disturbed they protrude two fleshy horns from the neck, known as “Osmaterium”. Host Plants: All citrus species and other plants like bael, ber, curry leaf plant, bawachi etc. Nature of Damage : Caterpillars feed on tender leaves right up to the midrib and defoliate the plants in case of severe infestation. Life History : Eggs : 70-180, singly on tender leaves, I.P.: 3-7 days. Larva: L.P. 2 weeks. Pupa : Pupation on plant, remain attached by silken threads. P.P. : 10-15 days, may extend up to 2-3 months in winter. Adult period : Male: 3 – 4 days, Female : 7-8 days. No. of generations : 4/year. S.O.: Pest is more active in monsoon season. Management Practices : 1) Hand picking of all the stages of insect and their destruction. 2) Spray 0.05% endosulfan or 0.2 % carbaryl or Bt 0.1%.
2. Leaf miner : Phyllocnistis citrella S.; Phyllocnistidae : Lepidoptera. Economic Importance: Most destructive pest, active in monsoon, maximum infestation noticed in seedling stage. The pest is suspected to be responsible for the spread of bacterial infection causing citrus canker. Marks of Identification : Moths : Small, silver white colour, forewings with brown stripe and prominent black spot near the tip. Caterpillar : Yellow in colour with brown mandibles. Host Plants : All citrus species, bael. Nature of Damage : On hatching larva feed on leaf tissues between upper and lower surfaces of leaves making glistering zigzag tunnels. The leaves turn pale, curl and finally dry. Besides, mined leaves may get bacterial infection which leads to citrus canker. Life History : Eggs: singly on underside of leaves (36 to 76 eggs), I.P.:3-6 days. Larva : 1- 2 weeks. Pupa : Pupation inside the larval mines of leaves, pp. 1-4 weeks. Life cycle is completed in 2-6 weeks. No. of generations : 9-13/year. S.O. : Pest is active in monsoon season. Population of the pests decreases during hot summer months. Management Practices: 1) Removal of infested leaves/twigs and their proper disposal. 2) Spray 0.05% monocrotophos, quinalphos or dimethoate or fenvalerate 0.01% or NSKE 5% as soon as attack is noticed.
3. Citrus psylla : Diaphorina citri K.; Psyllidae : Hemiptera Economic Importance : Most destructive of all pests of citrus, Also transmit “Greening melody”, a micoplasma disease in citrus. Marks of Identification : Adults : Small, dark brown in colour. Wings are folded like roof over body. Nymphs are spherical, pinkish, sedentary. Host Plants : Citrus and other plants belonging to Rutaceae and curry leaf plant. Nature of Damage : Both nymph and adult suck the cell sap from tender leaves, shoot and buds, which as a result curl, dry up and ultimately drop down. Complete crop failure is reported in case of severe infestation. 75
Life History : Eggs : 800 in leaf axis, I.P. : 4-6 days in summer and 22 days in winter. Nymph : N.P. 2 weeks in summer and 3-4 weeks in winter. Adult : Longevity may extend over 6 months. No. of generations : 9/year. C.O. : Pests over wintering in adult stage. Management Practices : Spray quinalphos or monocrotophos at 0.025% or formathion 0.04%, fenvalerate 0.01% as soon as new sprouts appear in June and January.
4. White fly and Black fly : Dialeurodes citri A & Aleurocanthus woglumi A Aleyrodidae : Hemiptera. Economic Importance : White fly and black fly are of common occurrence and destructive pest of citrus. It causes ‘Kolshi’ in citrus and reduce plant vigour. Marks of Identification : White fly : Adults : Minute insect (1 mm) with yellowish body and red eyes. Wings white or greyish, covered with mealy secretions. Nymphs and pupae : Are oval shaped, scale like and brownish with marginal bristle like fringes. Black fly : Smaller in size and black in colour. Host Plants : Citrus, cotton, castor, banana, coffee, mango, pomegranate, custard apple and some ornamental plants. Nature of Damage : Nymphs and adults suck the cell sap from leaves, as a result leaves wither and turn brownish. Nymphs excrete honey dew on which black sooty mould develops. The blackish coating commonly called “Kolshi”. Fruit setting is adversely affected in case of severe infestation. Life History : Eggs : Underside of leaves, I.P. : 10 days. Nymph : N.P. 3-10 weeks. Pupa : Pseudo pupa (Quescent stage) on underside of leaves. P.P. : 16-22 weeks. Management Practices : 1) Avoid close planting and water logging. 2) Clip off and destroy infested leaves. 3) Sprays 0.05 % monocrotophos or dimethoate or quinalphos for second and third instar nymphs. 4) Spray 0.08% monocrotophos or 0.1% dimethoate or quinalphos for the control of last instar.
5. Fruit sucking moth: Eudocima (Othreis) fullonica C.; Eudocima (Othreis) materna L.; Achoea janata L.; Noctuidae : Lepidoptera. Economic Importance : Moths puncture the fruits and causes fruit rot. Marks of Identification : Moth : Large sized, forewings grey or brown. Hind wings orange or yellow with black spot in the center and marginal dark bands. Kideny shaped black spots in E. fullonica and round black spots in E. materna. Larva:Typical semilooper and have stout appearance, full grown larva 5 cm long, velvety dark brown colour. Host Plants : Larva feeds on leaves of wild creepers like gulvel and wasanvel and moth feeds on fruits of citrus, mango, pomegranate, grape, cashewnut etc. Nature of Damage : Moths are nocturnal and seen flying in orchards after dusk. Moths puncture the ripening fruits and suck the juice. Bacterial infection to the infested fruit causes rotting.
Life History : Eggs : 300, on leaves of wild creepers I.P. : 3-4 days. Larva: L.P. : 20 days. Pupa : Pupation in soil, P.P. : 9 days. Life cycle is completed in 4-6 weeks. S.O. : Pests is active in kharif season. Management Practices : 1) Eradication of host plants viz. gulvel and wasanvel, etc. 2) Collection and destruction of moths at night. 3) Poison baiting (20 ml malathion 50 EC + 200 g jaggary + 2 lit. water). 4) Bagging of matured fruits with paper or cloth bags. 76
5) Quick removal and disposal of fallen fruits.
6. Bark eating caterpillar Or Bark borer: (i) Indarbela quadrinotata W.; (ii) I. tetraonis M.;Inderbellidae : Lepidoptera.
Economic Importance : It causes severe damage to citrus in Maharashtra State. Marks of Identification: Moth : Short, stout, ashy grey in colour. Larva: Dirty brown in colour, slender and measures 5 to 6 cm. Host Plants : Citrus, mango, ber, guava, pomegranate, jamun, aonla and other fruit crops and forest trees. Nature of Damage : Larvae bore into wood making short tunnels in which they hide during the day and come out at night to feed on the bark. As a result of feeding on bark the sap conducting tissues are damaged which interrupt the translocation of cell sap. Frass and silken threads over the bark surface form the webbing. The growth and fruit setting is adversely affected. Withering of branches. Life History : Eggs : 350, on bark in May-June, I.P. : 8-11 days. Larva : L.P. 8-10 months till about 3rd week of April. Pupa: Pupation inside larval tunnel, P.P.: 21-41 days. Moth longevity: 3 days. No. of generation : 1/year. Management Practices : 1) Remove ribbon like silken webs from affected branches/trunks, detect the larval tunnel and insert iron spike in it to kill the larva. 2) Inject CS2 or borer solution (2 parts CS2 + 1 part chloroform + 1 part creosote oil) in borer- holes and plaster the holes with mud or insert into the borer holes insecticide – soaked cotton plugs and plaster the holes with mud. The insecticides for per litre of water are 4g carbaryl 50 WP or 2 ml dichlorvos 100 EC or 3 ml. endosulfan 35 EC., petrol, kerosene. These chemicals should be applied after removing webbings. 3) Spot application (spraying) of monocrotophos or dichlorvos or quinalphos at 0.08% or fenvalerate 0.04%.
7. Aphids : Toxoptera aurantii F., T. citricidus K.; Aphididae : Hemiptera. Nature of Damage : Both nymph and adult suck the cell sap from tender shoots and leaves, as a result leaves curl, shoots wither, dry and the vigour of the plants declines. Severe attack at flowering may affect fruit setting. Besides, pest acts as vector of ‘tristeza’ virus diseases. Host Plants : Citrus, group. Life History : Completed with 8-10 days. Management Practices : Spray with 0.05% dimethoate, or monocrotophos or methyl demeton as soon as infestation noticed.
Minor pests : 8. Scale insect : Red scale : Aonidiella aurantii M.; Coccidae : Hemiptera 9. Mealy bug : Planococcus citri, (Risso); Pseudococcidae : Hemiptera. 10. Mites : Oligonychus citri M.; Tetranchidae : Acarina, 11. Citrus Nematodes : Tylenchulus semipenetrans (Cobb.); Tylenchulidae : Tylenchida.
Other Minor Pests : Thrips
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Fruit flies Fruit sucking bugs Fruit borer Termites
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Exercise No.24 STUDIES ON PESTS OF GRAPEVINE
Material : Preserved pests specimens and damaged plant parts. Major pests : 1. Flea beetle Or Udadya beetle : Scelodonta strigicollis M.; Chrysomelidae : Coleoptera Economic Importance : It causes severe damage to buds and tender shoots. The damage may extend from 11 to 31 %. Marks of Identification : Adults : Small (4 to 5 mm long) shining flea beetle with metallic bronze colour and 6 dark spots on the elytra. Grub : Small, dirty white. Host Plants : Specific to grapevine, however recorded on pangara. Nature of Damage : Adult feed voraciously on sprouting buds and tender shoots soon after pruning. Buds dry up and do not develop. Beetle also feed on mature leaves giving shot hole appearance. Grubs feed on roots but do not cause severe damage. Life History: Eggs : In crevices of vines and under bark or in soil. I.P.: 4-8 days. Larva : L.P. 35-45 days. Pupa : Pupation in soil, 6-8 cm deep in earthen cells, P.P.: 7-10 days. Life cycle completed in about two months. C.O.: Adult beetles hibernate under the bark from Nov.- March. S.O.: Pests is very destructive to fresh flush after pruning. Management Practices : Remove the loose bark and spray with 0.05% malathion or 0.05% chlorpyriphos or 0.2% carbaryl 50 WP/ 0.05% dimethoate or dusting methyl parathion 2%. First spraying immediately after pruning and second spraying 10 days after sprouting.
2. Thrips : Rhipiphorothrips cruentatus H.; Thripidae : Thysanoptera Economic Importance : It is one of the important pests of grapevine causing scab formation in berries. Marks of Identification : Adult : Minute with black wings having fringes. Females dark brown, males bright yellow. Nymphs : Reddish. Host Plants : Polyphagous – mango, pomegranatge, rose, guava, jack fruit, cashew etc. Nature of Damage : Both nymphs and adults scrap the ventral surface of leaves, flower stalks, berries and suck the oozing cell sap. As a result, affected leaves show silvery white schorchy patches with curly tips, flowers shed and scab formation noticed on infested berries. Life History : Both sexual and parthenogenetic reproduction occur. Eggs: In leaf tissues, I.P. 3-8 days. Nymph: Nymphal period 11-22 days. Pupa: Pupation in soil, P.P.: 2-5 days, Adults longevity: male 2 to 6 days, female 18-20 days. Life cycle: Completed in 14-33 days. No. of generation: 5- 8/year. C.O.: Pests overwinter in pupal stage in soil. S.O.: Pest is active in summer. Management Practices: Spray with 0.03% dimethoate or methyl demeton, monocrotophos or 0.01% cypermethrin, first spray immediately after pruning in April and October.
3. Mealy bug: Maconellicoccus hirsutus Green; Pseudococcidae: Hemiptera. Economic Importance : It causes severe damage, infest grape bunches. Marks of Identification : Adults : Females are pinkish, covered with mealy white waxy secretion. Eggs and crawlers are orange in colour. Host Plants: Grapevine, Hibiscus (bhendi, ambadi), mulberry, custard apple, guava etc. Nature of Damage : Both nymphs and adults suck the cell sap from leaves, shoots and bunches. Develop sooty mould on bunches and cause severe damage to fruit bunches. Life History : Eggs : 350-500, under bark, cracks, crevices in cottony cushion ovisac, I.P. : 5-10 days. Nymph: Female – 3 instars, male – 4 instars. Pupa: Noticed only in males. Life cycle: Completed in 1 month. S.O.: Pest is active in Feb.- March and June to August. Management Practices:
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1) Debarking of vines and application of insecticides like methyl parathion. 2D on stem and branches immediately after pruning. 2) Sticky bands around the stem near ground level. 3) Spraying of fruit bunches with 0.05% dichlorvos in combination with fish oil rosin soap @ 2.5 g/lit or sandovit 1-2 ml./lit (wetting & sticking agent). 4) Release of exotic predator Cryptolaemus montrouzieri Muls @ 2500-3750/ha. or 5 grubs/ beetles per vine. 5) Spraying of Verticilium lecanii 0.2 %.
4. Stem Girdler : Sthenias grisator Fab.; Cerambycidae : Coleoptera. Economic Importance : Minor pests but may assume a serious status. Marks of Identification : The adult beetle is dark coloured, greyish-brown with the elytra bearing an eye-spot near their tips. The grubs are whitish, 10-12 mm long, with prominent mandibles and spines on thorax. Host Plants: Primarily grapevine but can also survive on mango, mulberry, citrus, ber etc. Nature of Damage : Grubs tunnel into the stem (dry wood). Beetles feed on bark and girdle the vine resulting into drying of branch. Girdling of green branches is an essential event before oviposition. Life History : Eggs : Under the bark of girdling point, I.P.: 8 days. Larva: Grub period 7-8 months. Pupa : Pupation inside larval tunnel, P.P.: 4-5 months. No. of generation : 1/year. S.O.: Pest is active from Aug-October. Management Practices : 1) Cut the affected branches below the point of girdling and destroy by burning. 2) Collection and destruction of beetles. 3) Spraying with 0.05% malathion or 0.2% carbaryl.
Minor Pests : 5. Cockchafer beetle: Adoretus spp.; Anomala spp.; Scarabacidae: Coleoptera. 6. Mites : Tetranychus urticae Koch.; Tetranychidae : Acarina. 7. Root-knot nematode : Meloidogyne incoguita (Cobb.) ; Heteroderidae : Tylenchida;
Other minor pests : Stem borer Leaf roller Termites Leaf hoppers
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Exercise No.25 STUDIES ON PESTS OF POMEGRANATE
Material : Preserved pests specimens and damaged plant parts. Major pests : 1. Fruit borer /Anar caterpillar: Deudorix isocrates (Fab.); Lycaenidae : Lepidoptera. Economic Importance: Serious pest, regular in occurance causing 40-90% fruit damage. Marks of Identification: Adults : Medium sized, males are bluish violet while females are brownish violet with orange spatch on forewings. Larva: Short, stout, dark brown with short hairs and whitish patches all over the body and 2 cm long. Host Plants : Pomegranate, guava, orange, ber, aonla, mulberry, plum, peach, pear and some other wild fruits. Nature of Damage: Caterpillars bore the fruits, feed on pulp and seeds. Damaged fruits subsequently get infected by bacteria resulting in rotting of fruits. Such rotten fruits gives offensive smell and fall down. The excreta of the larva around the entry hole is seen. Life History: Eggs: On calyx of flowers or on fruits, I.P.: 7-10 days. L.P.: 18 to 47 days. Pupa: Pupation inside the fruit or on fruit stalk, P.P.: 7-34 days. Life cycle: 1-2 months. No. of generation: 4/year. S.O.: Pest is active throughout the year. Maximum during mrig bahar. Management Practices : 1. Spraying with 0.2% carbaryl or deltamethrin 0.002% as soon as appearance of flower buds. 2. Bagging of fruits if number of fruit trees are limited. 3. Remove and destroy affected fruits. 4. Prefere Ambia bahar.
2. Fruit sucking moths : Eudocima fullonica C.; E. materna L.; Achoea janata L.; Noctuidae : Lepidoptera. Note : Details of this pests are given under citrus, page no…….. .
3. Bark eating caterpillar : Indarbela tetraonis M.; I. quadrinotata W.; Inderbellidae : Lepidoptera. Note : Other details are given under citrus.
4. Thrips : Scirtothrips dorsalis H.; Retithrips syriacus M.; Thripidae : Thysanoptera. Nature of Damage : Nymphs and adults lacerate the leaves, flowers and fruits and rasp the sap that oozes out of these wounds. As a result, tips curl and dry away. Flowers are shed and brownish irregular spatches develop on fruits. (Other details are similar to grapevine thrips).
5. Shot–hole borer or Pin-hole borer: Euwallacea fornicatus Eich. Scolytidae: Coleoptera. Economic Importance : The incidence of this pest is spreading in most of the pomegranate growing area resulting in wilting and drying of plants. Marks of Identification : 2-3 mm, black shining beetles, grubs pinkish yellow, creamy white and apodous. Eggs are white, elongate, pupae white. Host Plants : 99 Host plants, tea, coffee, castor, pomegranate, etc. Nature of Damage: Female makes deep galleries inside stem, which hinders the translocation of nutrients and water. The larval brood feeds on the ambrosia fungal spores. (Monocrosporium ambrosium) which are carried and introduced by the young female at the time of gallery construction. The leaves turn yellow and the plant gets wilted. Life History : Egg, larval, pupal and adult periods are of 8-10, 21-26, 10-12 and 20-30 days respectively. Egg laying and pupation is within the stem. Management Practices : 81
1. Lindane 0.1% or chlorpyriphos 0.1% or carbaryl 0.4% along with geru (red soil) and 0.25% copper oxychloride (Blitox) as a paste application on stem is found quite effective for the control of shot-hole borer. 2. Drenching with chlorpyriphos 0.1% or lindane 0.1% + copper oxychloride 0.25% around stem in soil.
6. Mealy bugs: Drosicha mangiferae G.; Ferrisia virgata; Pseudococcidae : Hemiptera. Described under mango and guava.
7. Scale insects : Saissetia nigra N.; Coccidae : hemiptera. Economic Importance : It is becoming serious menace to pomegranate cultivation in Maharashtra State. Commonly known as ‘Black scale’. Marks of Identification : Adults : Female wingless, black brown, oval to circular in shape, Males are winged and are rare. Host Plants : Polyphagous- Pomegranate, cotton, castor, sandlewood, teak, guava, coffee. Nature of Damage: Nymphs and adults suck the cell sap from twings, shoots, leaves and fruits. Devitalization takes place resulting in premature shedding of buds & flowers. Fruits hecome small sized. Infested twings present sickly appearance and dry. Development of black sooty mould on leaves affect photosynthesis. Life History: Males are rare and occasionally seen. Females can lay the eggs without fertilization under the scale covering (Ovoviviparous reproduction). Preoviposion and oviposition periods are 19-27 and 23-42 days, respectively. A female lays 105 eggs within a period of 23 to 42 days, which hatch in about 4-8 days. The nymph become adult in about 36 days and adult female lives for about 44- 76 days. A generation is completed in 82-119 days. Management Practices : 1. Collection and destruction of severely infested twigs and fruits. 2. Spraying of quinalphos, dimethoate at 0.08% or malathion at 0.1%.
Minor pests : 8. White Fly : Siphoninus finitimus Sil.; Aleyrodidae : Hemiptera 9. Aphids : Aphis punicae; Aphididae : Hemiptera 10. Mites: Tenuipalpus punicae P&B; Tenuipalpidae : Acarina. 11. Hairy caterpillars : Euproctis spp.; Lymentriidae : Lepidoptera. 12. Root-knot nematode: Meloidogyne incognita (Cobb.); Heteroderidae : Tylenchida
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Exercise No.26 STUDIES ON PESTS OF GUAVA
Material : Preserved pests specimens and damaged plant parts. Major pests : 1. Fruit fly : Bactrocera diversus Coq., B. zonatus S.; Trypetidae : Diptera Economic Importance : It is a pest of potential importance on guava. Marks of Identification : Full grown maggots pale creamy colour (5 to 6 mm long). Adults are smoky brown with greenish black thorax with yellow marking. Host Plants : Polyphagous pest – Besides guava, it attacks banana, citrus, mango, jamun, papaya, melons and some other cucurbit fruits Nature of Damage : After hatching the grubs bore into fruits, feeds on bulp, rotting and dropping of fruits. Life History : Eggs : Under the rind of the fruit, I.P : 1-4 days. Larva : L.P. 4-5 days. Pupa : Pupation in soil, P.P. : 7-13 days. Total life cycle : 2-3 weeks. S.O.: Pest is active throughout the year. C.O. : Adult stage. Management Practices : 1. Harvesting of fruit crops at proper time. 2. Collection and destruction of infested fruits. 3. Use of Rakshak traps with methyl eugenol. 4. Spraying of fenthion 0.05% or deltarmethrin 0.001%. 5. Spray bait : 20 ml. malathion + 200 gms jaggery + 20 lit water.
2. Bark eating catterpillar or Bark borer: I. tetraonis M.; I. quadrinotata W.; Indarbellidae : Lepidoptera. The details of this pest are given under citrus.
3. Spiralling white fly: Aleurodicus dispersus Rus.; Aleyrodidae: Hemiptera. Economic Importance : White fly, Aleurodicus dispersus Russel (Hemiptera) is a serious pest of guava, Psidium guajava orchards in Kolhapur since January 1997. It is spreading in Maharashtra specially in districts Kolhapur, Sangli, Satara, Pune, Solapur, Osmanabad, Beed, Latur etc. Marks of Identification: The pest is characterized by having dark reddish-brown eyes, fore wings with two characteristic dark spots. The wings are clear in newly emerged individuals but within few hours get covered with white powdery material. The 1st instar larvae are crawlers but settle later on near the spiral pattern eggs laid. The 3rd instars are characterized by having numerous evenly spaced short, glass like rods of wax along the sides of the body. The 4th instars are with copious amount of white material covered and with long glass-like minute rods. Host Plants : Alarming on several agricultural and non-agricultural crops like guava, custard apple, banana, brinjal, mango, papaya, cotton, citrus, pomegranate, chilli, coconut, fig, sapota, groundnut & other flowering and ornamental plan Nature of Damage : Damage to the crop is caused by both nymphs (larvae) and adults by sucking the cell sap, secreting boney dew like substance and further creating sooty moulds on leaves, as a result photosynthetic activities, growth of plant and fruit setting is adversely affected. Infected leaves becomes yellow, dry and drop down finally. Life History : The egg stage lasts for 4-6 days, the larval 14-21 days and the pupal stage lasts for 2 to 5 days. Thus the total life cycle is completed in about 21-32 days only. Management Practices : 1. Dichlorvos or malathion 0.1%. 2. Diflubenzuron 0.012% 3. Release of Encarsia parasitoids @ 1 lakh/ha.
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4. Mealy bugs : Ferrisia virgata Cock.; Pseudococcidae : Hemiptera Marks of Identification : Adult female apterous, oval, covered with white waxy filaments and two long waxy processes at posterior end. Males are winged. Host Plants : Custard apple, aonla, citrus, banana, guava, grapevine and jack fruit. Nature of Damage : Nymphs and adult female remains clustered on ventral surface of leaves, terminal shoots and sometimes on fruit and suck cell rap. Yellowing of leaves, premature shedding of fruits. Life History : Incubation period 3 to 4 hours. Egg masses on leaves under female. The developmental period of nymph of male and female varies from 31 to 57 and 26 -47 days respectively. Longevity of male is 1-3 days and female 36-53 days. Management Practices : Spray with 0.1% acephate or monocrophos or 0.2% carbaryl, Verticillium lecanii 0.2%, use of predator Cryptolaemus montrouzieri.
Minor Pests : 1. Scale insect : Chloropulvinaria psidii M.; Coccidae : Hemiptera.
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Exercise No.27 STUDIES ON PESTS OF FIG, AONLA AND CUSTARD APPLE
Material : Preserved pests specimens and damaged plant parts. I) PEST OF FIG Major Pests : 1. Jassids : Velu caricae G.; Jassidae : Hemiptera Economic Importance : It is one of the most destructive pests of fig. Marks of Identification : Adults : Small, wedge shaped, reddish brown with blackish compound eyes, walk diagonally. Host Plants : It is specific pests of fig only. Nature of Damage : Both nymph and adult suck the cell sap from ventral side of leaves. As a result, leaf margins turn yellow, curl and becomes reddish brown producing typical “hopper burn” symptoms. Fruiting capacity is adversely affected. Life History : Eggs : 36, singly inside the leaf tissues, I.P. : 6-13 days. Nymph : N.P. : 9-12 days. S.O.: The activity of pests coincides with the period when young foliage is produced, i.e. the first week of October. Management Practices : Spray with 0.1% carbaryl or 0.03% moncrotophos, 0.03% dimethoate. First spray should be given in the first week of October when new flush appears and subsequent sprays as and when infestation noticed.
2. Stem borer : Batocera rubus Lin.; B. rufomaculata de Geer. Cerambycidae : Coleoptera. (Described under mango).
3. Mites : Aceria ficus (Cotte); Eriophyidae : Acarina. (Refer the polyphagous pest page no………). Minor Pests : 1. Mealy bugs : Drosicha mangiferae G.; Pseudococcidae : Hemiptera 2. Scale insects : Hemiberlesia lataniae A. Coccidae : Hemiptera
II) PESTS OF AONLA : Major Pests : 1. Fruit borer: Meridarchis scyrodes M.; Carposynidae ; Lepidoptera Economic Importance : Most destructive pest of ber. Losses to the extent of 70 % are noticed in susceptible varieties. Marks of Identification: Adult: Moth is small and dark brown. Caterpillar: Small, dark pinkish to reddish, cylindrical, slightly tapering to both ends. Host Plants : Ber, jamun, olive and aonla. Nature of Damage : Caterpillar enters the fruit by puncturing a hole in rind and feeds on seed. Infested fruits drop down, ferment and emit disagreeable odour. Life History : Eggs : 11-34, singly in depression near the stalk of fruit. I.P. : 4-7 days. Larva: L.P. : 13-17 days. Pupa : Pupation in soil, P.P. 5-8 days. Adult: Longevity 3-4 days. Life cycle : 1 month. C.O.: Pest is carried through shed fruits from one season to other in hibermating larval stage. S.O. : Activity of the pest is in fruiting season, from Sept. to Jan. and infestation reaches at its peak in middle of November.
Management Practices : 1. Removal and destruction of infested and shed fruits. 85
2. Spray with 0.2% carbaryl, fenvalerate 0.01% or deltamethrin 0.002%, well before harvesting of fruits (half maturity stage). 3. Growing of less susceptible varieties e.g. Surati No.1, Kashi, Mehroon and Mehroon Khirani.
2. Bark eating caterpillar : Indarbela quadrinotata W.; I. tetraonis M.; Indarbellidae : Lepidoptera (Described under citrus).
Minor Pests : Aphids, leaf folder etc.
III) PESTS OF CUSTARD APPLE : 1. Mealy bug : Ferrisia virgata; Maconellicoccus hirsutus G. Pseudococcidae : Hemiptera. Details are given under grapevine & guava.
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Exercise No.28 STUDIES ON PESTS OF BER
Material : Preserved pests specimens and affected plant parts. Major Pests : 1. Ber fruit borer: Meridarchis scyrodes M.; Carposynidae : Lepidoptera Economic Importance : Most destructive pest of ber. Losses to the extent of 70 % are noticed in susceptible varieties. Marks of Identification: Adult: Moth is small and dark brown. Caterpillar: Small, dark pinkish to reddish, cylindrical, slightly tapering to both ends. Host Plants : Ber, jamun, olive and aonla. Nature of Damage : Caterpillar enters the fruit by puncturing a hole in rind and feeds on pulp. Infested fruits drop down, ferment and emit disagreeable odour. Life History : Eggs : 11-34, singly in depression near the stalk of fruit. I.P. : 4-7 days. Larva: L.P. : 13-17 days. Pupa : Pupation in soil, P.P. 5-8 days. Adult: Longevity 3-4 days. Life cycle : 1 month. C.O.: Pest is carried through shed fruits from one season to other in hibermating larval stage. S.O. : Activity of the pest is in fruiting season, from Sept. to Jan. and infestation reaches at its peak in middle of November. Management Practices : 1. Removal and destruction of shed fruits. 2. Spray with 0.2% carbaryl, fenvalerate 0.01% or deltamethrin 0.002%. 3. Growing of less susceptible varieties e.g. Surati No.1, Kashi, Mehroon and Mehroon Khirani.
2. Ber fruit fly : Carpomyia vesuviana C.; Trypetidae : Diptera. Economic Importance : It causes severe damage to fruits to the extent of 77% has been noticed. Fleshy and late maturing varieties are more susceptible. Marks of Identification : Adult flies : Small, brownish yellow, lodgitudinal strips on thorax and wings transparent, with four yellow cross bands Maggot : Creamy white, about 6 mm long. Host Plants : Only ber. Nature of Damage : Maggots feed on fleshy and juicy pulp. The infested fruits turn dark brown, rot and give offensive smell. Life History : Eggs : Inside the epidermis of ripening fruits, I.P. 2-3 days. Larva : L.P. 9-12 days. Pupa : Pupation in soil, 5-7.5 cm deep under the tree. P.P. 11-13 days in summer and 45-87 days in winter. No. of generation : 3 /year. S.O.: Pest is active in winter, maximum damage during Feb- March. Management Practices : 1. Remove and destroy infested fruits. 2. Spraying with 0.1% carbaryl as soon as infestation noticed. 3. Application of spray bait (20 ml malathion + 200 g. jaggery + 20 lt. water). 4. Rake soil around trees frequently during summer to expose and kill pupae. Minor Pests : 3. Hairy caterpillar : Thiacidas postica WIK.; Noctuidae : Lepidoptera. 4. Jassids : Amrasca lybica de Berg.; Jassidae : Hemiptera. 5. Tingid bug : Monosteira spp.; Tingidae : Hemiptera. ***********
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Exercise No.29 STUDIES ON PESTS OF BANANA AND SAPOTA
Material : Preserved pests specimens and affected plant parts. (I) PESTS OF BANANA : Major pests : 1. Root stock weevil : Cosmopolites sordidus G.; Curculionidae : Coleoptera Economic Importance : Most destructive pest of banana in Maharashtra. Marks of Identification : Adult weevil : Small (1cm) shiny black and have long curved snout and short eleytra. Grub : Creamy white, stout, fleshy and legless with spindle shaped body (1 cm) Host Plants: Only on banana, prefer the varieties viz., Malbhog and Champa. Nature of Damage : Grubs bores into stem or sucker. As a result, the affected stem get riddled with holes while the roots are weakened. Bacterial and fungal infection leads to rotting. With strong blast of wind, the plants break down from the place of infestation. If the fruits are formed, they are few in number and inferior in quality. Both grub and weevil are the damaging stages. Life History : Eggs : In decaying leaf sheath or rhizome or soil near stem. I.P. : 1 week. Larva : L.P. 2-6 weeks, Pupation 10-12 days, pupation in rhizome or soil. Adult: Weevil sluggish and avoid day light, they live upto 2 years and can remain without food for 6 months. Management Practices : 1. Healthy suckers or rhizomes should be used for planting. 2. Spray with 0.05% dimethoate or carbaryl 0.1% or apply carbofuran 3 G. @ 40 g/sucker or phorate 10 G @ 15 g/sucker around the collar of affected plants. The treatment is to be repeated once in a month. 3. Uproot and burn the severely infested plants.
2. Aphids : Pentalonia nigronervosa Coq.; Aphididae : Hemiptera. Economic Importance : Sporadic pest but its importance concern with its activity as vector of the disease ‘bunchy top’ and chlorosis or heart rot. Marks of Identification : Adults are 1 to 2 mm long brown in colour with long antennae. Both alate and apterous forms are common. Nature of Damage : Although the direct damage is by sucking the cell sap, pest causes serious damage indirectly by acting as a virus vector and transmitting the ‘bunchy top’ disease. In case of severe infestation, leaf dwarfing and leaf or heart-rot and chlorosis, leaf curling are noticed & fruit bunches becomes small. Life History : The aphids reproduce by agamic viviparity. The life cycle is completed within 7 to 12 days. Management Practices : 1. Remove the virus infested plants and destroy. 2. Spraying of 0.05 % dichlorvos, dimethoate or methyl demeton.
3. Burrowing nematode : Radopholus similis (Cobb) Thorne Hoplolaimidae : Tylenchida Economic Importance: Important non-insect pest of banana causing spreading decline of trees and migratory endoparasitic in habit. Marks of Identification : Both male and female are thread like, elongate, microscopic, 0.4 to 0.9 mm in length. Host Plants: banana, citrus and other plantation crops and spices.
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Nature of Damage : These are migratory endoparasites, enter into roots at any point. Reddish brown cortical lesions are formed on roots, growth of the plant retarded, some times mature plant collapse. Life History : The female lays eggs on root. The total life cycle is completed within month. Management Practices : 1. Soil application at planting with phorate 10 G. @ 15 g/sucker or carbofuran 3 G @ 40 g/sucker reduces the nematode population. 2. Application of non-edible, oilseed cake like neem or karanj cake @ 1500-2000 kg/ha. will also help in reducing the nematode population. 3. Nematode free rhizomes/seedlings should be planted. 4. Crop rotation : Sugarcane after banana. 5. Avoid the planting of Robusta variety
Minor pests : 4. Tingid bug : Stephanitis typicus Dist.; Tingidae : Hemiptera
(II) PESTS OF SAPOTA (CHIKU) : 1. Chiku moth : Nephopteryx eugraphella R.; Pyralidae : Lepidoptera Economic Importance: It causes considerable damage to leaves and buds. Marks of Identification : Adult moth : Small, grey coloured, slender bodied insect having black forewings with yellow spots on the basal half and black transverse lines on the remaining half. Caterpillar : Small, active, deep pink in colour with 3 longitudinal pinkish brown strips on each side of the body. Host Plants: Sapota and bakul. Nature of Damage: The caterpillar webs the tender leaves with silken treads & excreta and feeds on them under concealed condition. Also bore the buds and tender fruits. The infestation of the pest can be detected by the presence of webbed shoots, dark brown patches on leaves and dried leaves in clusters on the tree. Life History : Eggs : 225, singly or in groups on tender shoots or ventral side of leaves, I.P. : 2-4 days in summer and 4-11 days in winter. Larva : L.P. : 13-26 days in summer and 31-60 days in winter. Pupa : Pupation inside the fold of webbed leaves. P.P. 1-2 weeks in summer and 2-4 weeks in winter. Life cycle : 4-5 weeks in summer and 7-13 weeks in winter. S.O. : Pest is active in June- July. Management Practices : 1. Removal and destruction of infested clumps keep the pest under check. 2. Spray with 0.1% carbaryl, 0.05% quinalphos or chlorpyriphos.
2. Sapota seed borer : Trymalitis margarias Meyrick; Tortricidae : Lepidoptera Economic Importance: The severe incidence of the pest has been noticed since 1999-2000 in Thane district resulting in 40 to 90% infestation. Marks of Identification : The full grown larva is pinkish in colour, 12 to 13 mm in length. Adults are small (7 to 11 mm long) forewings whitish with grayish spots, hindwing creamy, with thick hairs at the margins. Host Plants: Sapota Nature of Damage : Larva is damaging stage. After hatching, the larva bores immature fruits, enters into seed through micropyle, feeds on immature milky endosperm of the seed leaving its excreta in the seed. The full grown larva comes outside the fruit by making gallery in pulp and makes exit hole. Finally rotting of fruits may takes place. Life History : The female lays eggs on fruits surface ranging between 7 and 272, singly or in batches of 2 to 4. Incubation period 10-12 days. Larva period 10 to 13 days. Pupa: Pupation takes place on
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leaves by folding leaf margins. Pupation period 12-13 days. The longevity of adults: 3-5 days. Total life cycle is completed by 31-36 days. Management Practices : 1. Collection and destruction of fallen fruits and leaves by burning. 2. Proper pruning of trees to allow sunlight 3. Conservation of red ants (predators). 4 Spraying with any one of the following insecticide alternatively at an interval of 15-20 days. (a) Endosulfan 0.05%; (b) Dichlorvos 0.05%; (c)Malathion 0.1% (d) Carbaryl 50 WDP 0.1%.
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Exercise No.30 STUDIES ON PESTS OF COCONUT, ARECANUT AND OTHER PALM TREES
Material : Preserved pest specimens and affected plant parts. Major pests : 1. Rhinoceros beetle or Black palm beetle : Oryctes rhinoceros L.; Dynastidae : Coleoptera. Economic Importance : Most destructive pest causes serious damage to young trees. Marks of Identification : Beetle : Stout, elongate, blackish in colour, 3.5 to 5 cm. long, head bears a large tapring horn. Horn is well developed in male than the female and female is slightly smaller in size. Grub : Stout, fleshy, 10 cm long and always curl up ventrally, whitish, wrinkled. Host Plants: Coconut and other plams, occasionally banana, pineapple etc. Nature of Damage : Only beetles are harmful. They damage unopened central leaflet (tender fronds) and feed voraciously on softer tissues of growing points, with the result the growth of the tree is arrested which ultimately wither and dies. Injury can be recognized on the basis of clipped leaves (fan like appearance) and fibrous mass oozes out of the bored hole. The Beetles are nocturnal and not capable of longer flight. Life History : Eggs : in decaying organic matter or in manure pits or compost heaps, I.P.: 8-14 days. Larva: L.P. 4-5 months. Pupa: Pupation in soil, 15-60 cm deep, P.P.20-60 days. Adult: Beetles are nocturnal in habit – 76-219 days. Life cycle: Completed in 10-12 months. S.O.: Pest is active in monsoon season. Management Practices : 1. Treating manure pits with 0.1% carbaryl or 10% carbaryl dust or 2% methyl parathion dust once in three months reduce the intensity of infestation. 2. Extracting beetles with iron hooks. 3. Filling bored holes as well as leaf axills with 2% methyl parathion dust + sand (1 : 1) to avoid re-infestation. 4. Removal and destruction of decaying organic matter within or near about orchards.
2. Red plam weevil : Rhynchophorus ferrugineus F.; Curculionidae : Coleoptera Economic Importance : Most destructive pest, common on matured palm. Marks of Identification : Adult weevil : Reddish-brown, bigger sized with curved snout, 3 - 4 cm in length. Grubs: Brownish fleshy and 5 cm long. Host Plants: Coconut and some ornamental palms. Nature of Damage : All the stages of the pest are passed on palm trees. Grubs bore into the trunk near the growing points and feed on soft tissues. A few small holes occur in the crown from which chewed fibers come out and brownish sap oozes out. In young palm the top wither while in older ones the top portion bends and beraks. Life History: Eggs : 204, in soft tissues at the base of leaf sheath, cuts of wounds on the trunk, I.P. 2-5 days, Larva : L.P. 24-61 days. Pupa: Pupation in cocoons of fibrous material,P.P.18-34 days. Life cycle: 50-90 days. S.O.: Pest is active throughout the year. Management Practices : 1. Fill the leaf axis with 2% methyl parathion dust + sand (1 : 1) to kill the female resting in leaf axis. 2. Painting of cuts, scars and wounds immediately with lime or coal-tar for preventing egg laying. 3. Inject monocrotophos 20 ml/palm by drilling a slanting hole on trunk, one metre above ground level, with the help of bent funnel and close the hole with cement or mud. Care
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should be taken to harvest all matured nuts prior to treatment or do not use the nuts from such treated palms for at least 3 months thereafter.
3. Black headed caterpillar: Opisina arenosella WIK.; (= Nephantis serinopa M.) Xylorictidae : Lepidoptera. Economic Importance : It causes severe damage to matured palms. The outbreaks of the pest occurs in the dry hot months. Marks of Identification : The adult moth is medium sized. Caterpillar : Slender, elongate, pale grayish with blackish head and 15 mm long. Host Plants : Coconut and other plams. Nature of Damage : Caterpillars feed on tender leaflets by remaining inside the leaf folds, in galleries made of silken threads and excreta. As a result, dried patches are seen on fronds and trees starts withering. Life History: Eggs: 130, tip of older leaves, I.P. 5 days. Larva : L.P.: 6 weeks. Pupa: Pupation inside the silken galleries of leaf, P.P.12 days. Life cycle: 2 months. S.O.: Pests is active in hot months i.e., from March to May. Management Practices : 1. Prompt removal and destruction of affected leaflets showing larval galleries along with caterpillars. This will check the population build up of the pest. 2. Spray with 0.1% carbaryl or 0.05% monocrotophos or dichlorvos as soon as pest appears. 3. Release of larval and pupal parasitoids such as Microbracon brevicornis M. and Perisierola nephantidis M. are found useful in controlling the pest. 4. Release of larval parasitoide, Goniozus nephantidis in coconut plantation in the month of March when pest assumes peak activity reduces the pest population effectively. 5. Use of light traps.
4. Eriophyid mite : Aceria guerreronis Keifer; Eriophyidae : Acarina. Economic Importance : Most important pest of coconut now days causing huge losses of the fruit yield and quality. Marks of Identification : Very small, elongate, wormlike, creamy white, microscopic in nature, measuring 0.25 mm, with two pairs of legs both in nymphs and adults. Host Plants : Coconut. Nature of Damage : The nymphs and adults feed by scrapping the surface of developing nuts under cover of the bract perianth which leads to premature nutfall and also leads to inferior quality, reducing the size and yield due to sucking of cell-sap. The nuts show typical triangular, brown, warty skin after maturity, deformed and ‘T’ shaped split may appear on the surface. Life History: The complete development from egg to adult takes about 10 to 12 days. Management Practices : 1. Root feeding of 2% Borax @ 250 ml/palm or soil application of borax @400-600 g/palm. 2. Root feeding of monocrotophos 15 ml in 15 ml water per palm or spraying as spot application of triazophos or monocrotophos 5 ml/litre of water.
5. Rats : Rattus rattus Wrougall; Muridae : Rodentia; Refer polyphagous pests page no…….. .
Minor Pests : 6. Termite: Odontotermes obesus R.; Termitidae : Isoptera 7. Mites : Raoiella indica Hirst ; Phytoptipalpidae : Acarina 8. Scale insects : Aspidiotus destructor Sign.; Coccidae : Hemiptera. 92
9. Mealy bugs : Pseudococcus coccotis C; Pseudococcidae : Hemiptera
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Exercise No.31 STUDIES ON PESTS OF CASHEWNUT
Material : Preserved pests specimens and affected plant parts. Major pests : 1. Tea mosquito or Mosquito bug: Helopeltis antonii S.; Capsidae: Hemiptera. Economic Importance: Major pest of cashewnut causing considerable damage. Marks of Identification : Adult bug : Small (7-9 mm), active, reddish brown having peculiar pin-like knobbed process, arising vertically from the thorax & have long legs and antennae Bugs having a mixture of red, black and white coloration. Nymph : Ant like, hairy and amber coloured. Host Plants: Polyphagous - cashewnut, tea, apple, grapevine and guava. Nature of Damage : Both nymphs and adults suck cell sap form the tender leaves, shoots and fruits. As a result leaves, shoots turn dark brown and then black, white blisters and scales appear on fruit. In case of severe infestation shoots dries up, nuts shrivel and fall prematurely. Life History : Eggs : 500, in tissues of tender shoots, buds, midribs and petioles of leaves. I.P.: 1-4 weeks. Nymph : N.P.3-6 weeks. Adult female bug live for 6-10 weeks. S.O.: Pest is active in rainy season. Heavy & continuous rains with no sunshine is favourable for its rapid multiplication. Management Practices : Spray with 0.1% carbaryl, 0.05% monocrotophos during flowering season gives satisfactory control of the pest.
2. Cashewnut stem borer or tree borer : Plocaederus ferrugineus Lin.; Cerambycidae : Coleoptera Economic Importance: This is the most important pest of cashew tree in South India. Marks of Identification : The adult is medium sized dark brown beetle. Full grown larva measure 7.5 cm, whitish yellow colour. Host Plants: Cashewnut. Nature of Damage: The newly emerged grubs bore into the bark and feed on soft tissues, making tunnels in all directions. The grown up grubs may also feed on wood. The opening of tunnels are plugged with a reddish mass of chewed fibre and excreta. The tree is weakened and it may die. Life History: The beetles lay the eggs under loose bark on the trunk. The life cycle is completed in more than a month and there are several overlapping generations in a year. Pupation takes place in larval tunnels. Management Practices: 1) Remove the grubs mechanically & destroy them. 2) Drench the basal trunk with 20 EC lindane or chlorpyriphos at 0.1% concentration. 3) Inject carbon disulphide into the tunnels and plaster with mud. 4) Destroy the severally infested plants.
3. Leaf miner: Acrocercops syngramma Mey.; Gracillaridae: Lepidoptera Economic Importance : This pest is distributed throughout the cashew growing area. Nature of Damage : The caterpillar mines through tender leaves. In mined area thin epidermal peel swells up as blistered patches. As the infested leaves mature the damage is manifested as big holes. Life History : The eggs are laid on very tender leaves. Incubation period is 2-3 days. Larval period 2 weeks. Pupal period 7-9 days, pupation takes place in soil.
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Management Practices : Spraying of 0.05% monocrotophos or endosulfan or malathion or 0.2% carbaryl 50 WP.
Minor Pests : 4. Leaf eating caterpillar: Sircula trifenestrata H.; Saturnidae: Lepidoptera. 5. Thrips : Rhipiphorothrips cruentatus H.; Thripidae: Thysanoptera.
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Exercise No.32 STUDIES ON PESTS OF BETELVINE
Material : Preserve specimens and damaged plant parts. 1. Mites : Refer the polyphagous pests page no………… .
2. Root-knot Nematode : Meloidogyne incognita; Heteroderidae : Tylenchida. Economic Importance : It causes severe damage to the crops like tomato, brinjal, bitter gourd, okra, bottle gourd, pomegranate, grape vine etc. Marks of Identification : Full grown female is microscopic, lemon shaped and 0.5 to 0.7 mm long 0.3 to 0.5 mm broad. While the juveniles (larvae) and the males are thread like and full grown males are about 1 mm long. Host Plants : Highly polyphagous, non-insect pest damaging different vegetable and fruit crops as well as pulses, ornamental and flower plants. Nature of Damage : After hatching the juveniles (larvae) enters into the roots and feed within the roots by sucking cell sap. This is endoparasitic nematode causing formation of root galls. It affect adversely on the absorption of nutrition by the roots and hence the symptoms like stunting growth, yellowing and wilting of the plants is observed. The damage by this nematode also encourages the root-rot disease. Life History : The females lay the eggs on surface of feeder roots in masses in gelatine matrix. The life cycle is completed within 3-5 weeks depending on climatic conditions. Management Practices : A) Cultural methods : 1) Summer follow and ploughing, 2) Crop rotation with non-host plants, 3) Soil solarization before sowing seed of vegetable crops, 4) Intercropping by sowing the crops like tagetes, sunnhemp, mustard, fenugreek etc., 5) Application of F.Y.M., organic amendments oil cakes like neemcake, caranj kake etc. @ 2 t/ha., 6) Discoiuraging the planting seedlings of vegetables or fruit crops from nematode infested fields. B) Biological control: Use of fungal biopesticidal formulations comprising Trichoderma and paecalomyces. C) Chemical Control : Application of granular insecticides like carbofuran 3G or phorate 10G @ 1 to 2 kg a.i./ha for vegetables and other seasonal crops and 4 kg a.i./ha for grown-up fruit crops.
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Exercise No.33 PESTS OF COFFEE & TEA
I) PESTS OF COFFEE : 1. Coffee Green Bug : Coccus viridis Green; Coccidae : Hemiptera. Marks of Identification : Crawlers are flat, ovate, slightly convex, pale green to yellowish green in colour. Nature of Damage : The scales crowd under the surface of leaves along the midrib and veins. Tender branches and developing fruits are also attacked. The leaves and fruits become discoloured, malformed and drop down. Plant become very weak and unproductive. Life History : They are produced ovoviviparously. Eggs: Female lays 300 to 500 eggs in a period of 2-5 months on leaves. I.P.: Few hours. Life cycle : Completed in 1 to 2 months. No. of generation: There are several generations in years. Management Practices : 1) Spray 0.1 % malathion or 0.03% dimethoate. 2) Use of Cryptolaemus montrouzieri.
2. Coffee Stem Borer : Xylotrechus quadripes Chevrolat; Cerambycidae : Coleoptera. Marks of Identification : Adult : Blackish brown beetle with prominent antennae, a characteristic pattern of yellowish bands on the elytra. Nature of Damage : The branches are tunneled by larvae, wilt & break easily. Life History : Eggs : 100 eggs per female are laid in cracks and crevices of trunk bark or primary branches. I.P. : 10 days. larval period 6-8 months. Pupation in the tunnels of stem. P.P. : 30 days. No. of generation/year : One. Management Practices : 1) Pest can be suppressed by removing and destruction of grubs. 2) Collection and destruction of beetles during their egg laying period. 3) Carry out swabbing of the main stem and branches with chlorpyriphos 20 EC @ 1.25 lit in 125 lit of water/ha. once during April-May and twice during September-January.
3. Coffee berry borer: Hypothenemus hampei Ferrari; Scolytidae: Coleoptera. Economic Importance : The most serious, world wide pest of coffee, native of Central Africa, detected in India during February, 1990. Now it has spread all over the major coffee growing areas in the country. Marks of Identification : The adult is small black beetle having sub-cylindrical body with thick hairs. The larva is white, legless, brown headed grub. Host Plants : Monophagous, on coffee only. Nature of Damage : The adult female enters in coffee berry through a circular pin hole at the tip of berry. The grub feed by tunneling into the beans (berries). The damage caused by this pest makes the coffee beans unfit for marketing. Life History : The females lay 30-90 eggs within beans (berries). The eggs hatch in 8-9 days. The larval period is completed in 2-3 weeks. The pupal stage lasts 6-8 days in larval galleries. Life cycle is completed by about 35 days. Management Practices : 1. Timely harvesting of berries. 2. Dip the infested berries in boiling water for 2-3 minutes to kill the pest stages inside the berries. 3. Dry the coffee berries to a prescribed moisture level. 4. Application of Beauveria bassiana @ 108 spores/ml with 0.25% groundnut oil at the beginning of monsoon.
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5. Spraying of endosulfan 0.07 %, dimethoate 0.06% or malathion 0.05%.
4. Stripped mealy bug: Ferrisia virgata Cock.; Pseudococcidae: Hemiptera. (Refer the pests of Guava).
II) PESTS OF TEA : 1. Tea Mosquito Bug : Helopeltis theivora Wat.; Miridae : Hemiptera. Marks of Identification : Adult : Female bug is orange across the shoulders and male is almost black colour. Nymphs : Wingless, look like spider. Host Plants : Tea, cashewnut, guava and medicinal plants. Nature of Damage : The bugs puncture the leaf frequently to suck the juice. While feeding saliva is injected and tissues are necrotized, which become brownish or black in colour. The entire leaves are shriveled and fall down. The severe attack causes complete defoliation of branches and plants look like the brooms. Life History : Eggs : eggs laid in the leaf axis, buds and often in the broken ends of the plucked shoots. I.P.: 5-27 days, depending upon the prevailing temperature. Nymphal period : Passes through 5 moults, 8 weeks in winter and 2 weeks in summer. Life cycle: Completed in 8-9 weeks. Management Practices : 1. Collection and destruction of nymphs with hand net during morning and evening. 2. Spray the trees with 0.05% malathion.
2. Bunch caterpillar: Andraca bipunctata Walk.; Bombycidae : Lepidoptera. Marks of Identification : Adults : are brown in colour, fore wings have wavy cross lines with two white spots near the outer margin. Larva: The full grown larva light yellow in colour. Host plants : Tea Nature of Damage: The larvae feeds on leaves and defoliate the the plants. Life History : Eggs : Female lays 500 eggs on underside of leaves. Incubation period: 8-12 days Larva : Larval period is 20 to 30 days. Pupa : Pupation in dry leaves on ground. P.P.: 15 to 30 days. No. of generation: 4 / year. Management Practices : 1. Collection and destruction of caterpillars. 2. Spray 0.05 % malathion.
3. Red Crevice Tea Mite: Brevipalpus phoenicis G.; Tenuipalpidae : Acarina. Economic Importance : It is a sporadic pest of tea in India, Srilanka and Malaysia Marks of Identification : Adult : Flat, elongate and oval in shape. It is scarlet red in colour with black mark dorsally. Nymphs: are flat, oval in outline and are scarlet red in colour. Host Plants : Tea, coffee, citrus, rubber and medicinal plants. Nature of Damage : Nymphs and adults feed on underside of leaves along the midrib at base. The loss of cell sap causes yellowing of leaves. The affected leaf petioles and the bark turn brown and dry up. Life History : Eggs : About 47 bright red oval shaped eggs are laid on the lower side of leaves or in the crevices of bark. I.P. : 6-13 days. Life cycle : Completed in 21-28 days. Management Practices : Spray 0.03% dicofol or 0.2% wettable sulpur.
4. Yellow Tea mite : Polyphagotarsonemus latus Banks; Tarsonemidae : Acarina. Marks of Identification : Adult is yellow with white strip on the dorsal side; eggs are oval and flattened. Nymphs are minute, white and pear shaped. Host Plants : Coffee, jute, tomato, potato, peppers, citrus, chillies, mango and rubber. Nature of Damage : It is a serious pests in tea nurseries. Due to severe infestation yellowing of leaves takes place. Pest is responsible as vector of virus disease, ‘leaf curl’ or ‘murda’ disease. 98
Life History : Eggs : laid on under side of young flush of leaves. I.P.: 2-3 days. Nymph: N.P. 2-3 days, P.P.: 2-3 days. Life cycle: Completed in 4-5 days. Management Practices : Same as under red crevice mite.
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Exercise No.34 STUDIES ON PESTS OF APPLE
Major pests : 1. San Jose Scale: Quadraspidiotus perniciosus (Comstock); Diaspididae : Hemiptera. Economic Importance : This insect pest has world-wide distribution and is the most serious pest in temperate region. Marks of Identification : The scale which forms a covering on the body of the insect is black or brown. Underneath, a lemon-yellow insect is visible when the covering is lifted. Host Plants : Prefers the plants belonging to the family “Rosaceae” such as apple, plum, pear, peach etc. Nature of Damage : All parts of the plant above ground are attacked. The nymphs and adults suck cell- sap from plant. The growth of plant is checked and in severe cases the plant may die. The infested fruit has scaly appearance affecting adversely on quality and market price. Life History : The pest is active from March to December and passes the winter in nymphal stage. Each female give birth to 200-400 nymphs. They become full grown in 3-40 days. The adult duration is 50-53 days. The males are winged insect and have a short life of 24-32 hours. There are four overlapping generations in a year. Management Practices : 1) Prune the infested material and keep good orchard sanitation. 2) The parasitoid Encarsia perniciosi may be released. 3) Spraying of methyl demeton 25 EC 0.05%. 4) In nursery protect the plant by application of carbofuran 3G @ 0.75-1.0 g a.i./plant.
2. Woolly Apple Aphid : Eriosoma lanigerum H.; Aphididae: Hemiptera. Economic Importance : This insect is a serious pest of apple in India and Pakistan Marks of Identification : Adults and nymphs are red to purple and covered with bluish white, cotton like wax filaments. Winged and wingless forms appear during the year. Host Plants : Apple, pear, crab apple etc. Nature of Damage : The nymphs and adults suck cell-sap from the bark of twigs and roots. Swelling or knots appear on the roots which hinder the normal plant functions. The twigs shrivel and young nursery plants may die quickly. Life History: The adult female reproduces parthenogenetically 116 young ones. The total duration of life history is 11 to 42 days. There may be 13 generations in a years. Management Practices: 1) Use of resistant root-stock like Golden Delicious, Northern spy etc. 2) Biological control by parasitoid Aphelinus mali. 3) Selection of healthy plants for nursery. 4) Application of methyl demeton or chlorpyriphos or fenitrothion at 0.05% or malathion 0.07%. Minor Pests: 3. Codling moth : Cydia pomonella Lin.; Tortricidae: Lepidoptera. 4. Tent caterpillar : Malacosoma indicum Walker; Lasiocampidae : Lepidoptera. 5. Indian Gypsy moth : Lymantria obtuscata Walker; Lymantridae : Lepidoptera. 6. Apple Stem borer : Apriona cinerea C.; Cerambycidae : Coleoptera.
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Exercise No.35 PESTS OF ORNAMENTALS IN FIELD AND POLYHOUSE
The uniform growing conditions in polyhouses throughout the year favours the multiplication of insect pests round the year. The damage caused by these pests includes curling, distortion, discolouration, browning and drying of plant parts which results in quantative and qualitative loss. The following pests are of common occurrence on ornamental crops and the crops under protected cultivation.
A) Foliage feeders / Bud borers : 1. Bud borer : Helicoverpa armigera Hub. 2. Tobacco leaf eating caterpillar : Spodoptera litura F. 3. Leaf miner : Liriomyza trifolii Burg.
B) Sucking pest complex : 1. Thrips : Thrips tabaci Lind.; Rhipiphorothrips cruentatus H. 2. White fly : Bemisia tabaci Genn. 3. Aphids : Microsiphum rosaeiformis Das. 4. Mealy bugs : Ferrisia virgata Cock. 5. Mites : Tetranychus spp.
C) Root feeders : 1. Plant parasitic nematodes : Root-knot nematode : Meloidogyne spp. Reniform nematode : Rotylenchulus reniformis Lin. & Oliv.
All the above pests have already been included in different crops and hence refer the respective pests.
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K. K. COLLEGE OF AGRICULTURE, NASHIK DEPARTMENT OF AGRICULTURAL ENTOMOLOGY
THEORY NOTES
Course No.:- ENTO-364
Course Title: - Introductory Nematology
Credits: - 2 (1+1)
Compiled By Prof. T. B. Ugale & Prof. A. S. Mochi Assistant Professor Department of Agricultural Entomology
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TEACHING SCHEDULE Semester : VI Course No. : ENTO-364 Course Title : Introductory Nematology Credits : 2(1+1) Lecture Topics Rating No. 1 Introduction- History of phytonematology and economic 4 importance. 2 General characteristics of plant parasitic nematodes. 2 3 Nematode- General morphology and biology. 4 4 Classification of nematode up to family level with 4 emphasis on group of containing economical importance genera (Taxonomic). 5 Classification of nematode by habitat. 2 6 Identification of economically important plant nematodes 4 up to generic level with the help of key and description. 7 Symptoms caused by nematodes with examples. 4 8 Interaction of nematodes with microorganism 4 9 Different methods of nematode management. 4 10 Cultural methods 4 11 Physical methods 2 12 Biological methods 4 13 Chemical methods 2 14 Entomophilic nematodes- Species Biology 2 15 Mode of action 2 16 Mass production techniques for EPN 2 Reference Books: 1) A Text Book of Plant Nematology – K. D. Upadhay & Kusum Dwivedi, Aman Publishing House 2) Fundamentals of Plant Nematology – E. J. Jonathan, S. Kumar, K. Deviranjan, G. Rajendran, Devi Publications, 8, Couvery Nagar, Karumanolapam, Trichirappalli, 620 001. 3) Plant Nematodes - Methodology, Morphology, Systematics, Biology & Ecology Majeebur Rahman Khan, Department of Plant Protection, Faculty of Agricultural Sciences, Aligarh Muslim University, Aligarh, India. Oxford & IBH Publishing Co. Pvt. Ltd., New Delhi. 4) Introductory Nematology (Theory Notes) – Dr. B. S. Shewale
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LECTURE NO. : - 1 INTRODUCTION Nematode is an important branch of biological science, which deals with complex, diverse group of roundworms known as nematodes that occur worldwide essentially in all environments. Nematodes are triploblastic (having three layers), bilaterally symmetrical, multicellular, unsegmented, generally microscopic worms with single cavity (Pseudocoelomic). Nematodes are generally found in all type of environment from the artic to the tropic sand, from the ocean depth to the tops of high mountains. They constitute the largest group of animal kingdom, comprising 80 to 90 percent at all multicellular animals. They are also mostly found in soil and most of the crops are attacked by them which are known as plant parasitic nematodes or phytonematodes. Nematodes are also known as eelworm, nemas and roundworm. Many species are important parasites of plant and animals, whereas others are beneficial to agriculture and environment. Nematodes that are parasites of man and animals are called Helminthes and the study is known as Helminthology. The name nematode was derived from the Greek word nemas (thread) and adios (form or resembling). The soil hector of all agro-ecosystem typically contain billions of plant parasitic nematodes. They feed on roots, buds, stems, crowns, leaves and developing seed of the plants. The damage caused by the nematodes on plant often overlooked because of association of symptoms like slow growth, stunting, yellowing and also could be attributed to the nutritional disorder. Existence of Nematodes Sea water : 50% Free living : 25% Animal parasites : 15% Plant parasites : 10%
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HISTORY OF NEMATOLOGY The history of animal parasitic nematodes is almost as ancient as the history of man. The Guinea worms and round worms as parasites of man were known to Egyptians as early as 1553-1500 B.C. As far as phytonematology is concerned Needham (1743) discovered the ear cockle disease caused by wheat gall nematode Anguina tritici which is the first record of plant parasitic nematode.
I) History of Nematology in World Early History (1743-1940):- Needham, T. (1743)- Wheat gall nematode, Anguina tritici. First record of plant parasitic nematode. Described associated diseases of wheat and other grains. Berkeley, M. J. (1855)- Discovered root-knot nematode, Meloidogyne spp in greenhouse cucumber. Goeldi, E. A. (1887), Neal, J.C. (1889), Atkinson, G.F. (1989), Bessey, E.A. (1901)- Contribution in Meloidogyne spp. Distribution, host ranges and disease complexes . Schacht, H. (1859)- First reported cyst forming nematode in sugar beet in Germany Schmidt, A. (1871)- Described sugar beet nematode, Central Europe Heterodera schachtti Carbon disulfide (CS2) – First report of effective chemical control of nematodes. Kuhn, J. (1857)- Described stem nematode, Ditylenchus dipsaci – on teasel heads. Serious problem to alfalfa, garlic, oats, onion, red clover, rye. Ritzema Bos, J. (1891)- Discovered foliar nematode, Aphelenchoides fragariae on straw berry. A. ritzemabosi on chrysanthemum A. Besseyi on rice. Cobb, N. A. (1914 to 1932)- Father of Nematology (America) Developed techniques for sampling soil for nematodes. Wet screening for extraction of nemas from soil. Methods of preserving/sectioning/mounting nematodes. Demonstrated presence of amphids, cephalic papillae, phasmids and deirids on tylenchs. Developed en face section techniques Filipjev, I. N. (1930)- Russian Scientist published a book “Nematodes that are of importance to Agriculture”. Chitwood, B. G.(1937)- Published a book “Introduction to Nematology”.
New Era in Nematology (1941-1990):- Cannon, O. S. (1941)- New York – Potato root eelworm (Golden Nematode) Heterodera rostochiensis (Globodera rostochiensis) Carter, C. C. (1943)- Discovery of D.D. (1, 3 Dicloropropane) soil fumigant for control of golden nematode. Christie, J. R. & Albin, F. E. (1944)- Discovery of races of root-knot nematodes.
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Chitwood, B. G.(1949)- Discovered genus Meloidogyne. Described several species of root-knot nematodes which made possible to : Determine the host range of individual species. Design keys for their identification based on morphological differences. Develop crop cultivars resistant to certain species. Study individual species cytologically and biochemically Early (1950)- Declining citrus in Florida due to burrowing nematodes, Radopholus similis. Christie, J. R. and Perry, V. G. (1953)- Demonstrated the importance of several ectoparasitic species (Belonolaimus, Dolichodorus, Xiphinema, Trichodorus etc.) Moutain, W. B. (1955)- Culturing plant parasitic nematodes under sterile conditions. Hewitt, W. B. (1958) - Discovery of transmission of virus diseases.
II) History of Nematology- India:- 1901 : Barber, C. A.- Root-knot nematode infesting tea in south India – First report of plant parasitic nematode in India. 1906 to 1919- Root-knot nematode – Black pepper in Kerala, Ufra disease of rice (Ditylenchus angustus) 1934: Ayyar, P. N. K.- Root-knot nematode infesting vegetables and other crops 1936: Dastur, J. F.- White tip nematode of rice (Aphelenchoides spp.) 1961: Jones, F. G. W.- First authentic report on potato cyst nematode, Heterodera (Globodera) rostochiensis from Nilgiris. 1965- First authentic report on Radopholus similis on banana from Kerala. 1966- Division of Nematology established at IARI, New Delhi. 1971- Indian Journal of Nematology 1977- AICRP on Nematode Pests of Crops and Their Control (14 centers).
III) History of Nematology – Maharashtra Dhande & Sulaiman (1961)- Reported occurrence of root-knot nematode on betel vine from Vadner Bhairav (Nashik) Manjrekar & Talgeri (1969)- Enumerated the problems of plant parasitic nematodes of Maharashtra in All India Nematology Symposium. Manjrekar (1977)- Submitted M.Sc. (Agri.) thesis and reported : M. incognita – Banana, Grapevine, Betel vine & Vegetables. T. semipenetrans – Citrus, R. reniformis – Grapevine. Ectoparasites – Helicotylenchus, Hoplolaimus, Xiphinema, Tylenchorhynchus January, 1978- AICRP on Nematodes at MPKV, Rahuri.
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Economic Importance of Plant Parasitic Nematodes The plant parasitic nematodes play a vital role in crop production as most of the crop including field, orchards, vegetables, kitchen garden; ornamental crops are attacked by various species of nematodes. More than 2000 species of phytonematodes belonging to about 200 genera have been described; while it is estimated that about 42000 species of phytonematodes may be present. It has been estimated that on global basis 12 percent crop loss due to diseases, 7 percent due to insects, 3 percent due to weeds and 11 percent due to nematodes. The annual crop losses due to these obligate parasites have been estimated to be about $78 billion worldwide. Estimated overall average annual yield loss of the world’s major crops due to plant parasitic nematodes was 12.3%. Estimated losses due to plant parasitic nematodes in developing countries were 14.6% and 8.8% for developed countries. On worldwide basis, the ten most important genera were reported to be Meloidogyne, Pratylenchus, Heterodera, Ditylenchus, Globodera, Tylenchulus, Xiphinema, Radopholus, Rotylenchulus and Helicotylenchus. In India, the losses caused in different crops are due to the following major nematode species. The seed gall nematode, Anguina tritici is responsible for ear cockle disease of wheat in Northern India. It also causes tundu or yellow slime disease with the association of a bacterium, Clavibacter tritici. The overall damage is one percent but sometimes it is as high as 80 percent. The root-knot nematode, Meloidogyne spp. is one of the few nematodes known to the farmers due to the spectacular symptoms of root gall formation on vegetable, pulses, fruits and ornamental plants. The percent yield losses due to this nematodes has been estimated to the tune of 28-47 percent in tomato, 26.2-50 percent in brinjal, 19.7-33 percent in chillies, 6.0-90 percent in okra, 38-47.2 percent in bitter gourd and 18-33 percent in melons at different AICRP projects in India. The cereal cyst nematode, Heterodera avenae causes Molya disease of wheat and barley in the states of Rajasthan, Haryana, Punjab, Delhi, U.P., Himachal Pradesh, Jammu & Kashmir. It may cause up to 50 percent or even a total loss of the crop. The reniform nematode, Rotylenchus reniformis attacks a large number of plants and causes considerable losses to vegetables and pulses varying from 4.8 to 14.9 percent loss in yield in different crops. Citrus nematode, Tylenchulus semipenetrans causes slow decline disease of citrus and also associated with ‘die-back’ in citrus. The burrowing nematode, Radopholus similis causes severe damage to many fruit crops including banana, spice crop and other plantation crops. It is responsible for spreading decline of citrus, black head disease of banana and root-rot disease of crops. The golden nematode of potato, Globodera rostochinensis is a serious problem in Nilgiri and Kodaikanal hills. An average loss of 9 percent is caused by this nematode. The root lesion nematode, Pratylenchus coffeae is important pest of coffee in South India. It causes foot-rot of young plants and decline or die-back of older plants. The above examples include only the major nematode pests. Besides infesting alone, they are also known to be associated with various bacteria, fungi and viruses in causing complex plant diseases which further increases the losses in yield of crops. The nematode problem is more important in developing countries, in tropical and sub- tropical regions.
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LECTURE NO. : - 2 General Characteristics of Phylum Nemata/Nematoda/Nematodes 1. The nematodes possess elongate, unsegmented, cylindrical or worm like body tapering towards both ends, unciliated and circular in cross section. 2. Body is bilaterally symmetrical. 3. They are aquatic, terrestrial and parasitic or free living. 4. The body is covered by tough and resistant cuticle secreted by epidermal (hypodermal) cells. 5. Terminal oral aperture (mouth) surrounded with lips and papillae. 6. Digestive system consists of feeding apparatus, oesophagus, intestine and rectum. 7. Body consists of two tubes. 8. The nervous system consists of circum-oesophageal nerve ring and longitudinal nerves. 9. Primitive excretory system is devoid of protonephridial cilia or matanephridial funnel. 10. The circulatory and respiratory systems completely absent. 11. The females have separate genital pore and males have a common opening known cloaca and well developed copulatory apparatus consisting of spicules and gubernaculum. 12. Females are oviparous or ovoviviparous or viviparous. The cleavage is terminated and growth is accompanied by molting. 13. Life cycle is direct and there are four juvenile stages.
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LECTURE NO. : - 3 Nematode - General Morphology and Biology Nematode exhibits considerable variation in their external and internal structure. Despite this structural complexity, certain basic principle is common to all nematodes General shape & size Nematodes : Triploblastic, bilaterally symmetrical, unsegmented, colourless, pseudo coelomate, vermiform and circular in cross section animals.
Fig: General Morphology of Nematode
Shape: Nematode show great variation in their morphological characters. The plant parasitic nematodes are slender, spindle shaped or fusiform organisms. The nematodes when relaxed with gental heat either lie straight (Pratilenchus) or slightly curved (Hoplolaimus) or curved in ‘C’ shaped (Tylenchorynchus) or form a spiral (Helicotylenchus). Sexual dimorphism in few species. Lemon, pear, kidney, saccate shape.
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Size: Their size may vary from 0.2 mm to about 12 mm length with an average of 0.01 mm and 0.5 mm in breadth (1 to 15 % to length). Males are smaller than females
Body regions: The nematode body is not divisible into definite regions as that of insects, however there are certain subdivisions like anterior part of the body having the mouth, lips and stoma is called head and it is continuous with main body. The portion between the head and the base of oesophagus is the neck. The part of the body beginning from the anus or cloca and extending up to posterior extremity is the ‘tail’. Longitudinally, the body can divide into four zones: the ventral which bears the natural openings like excretory pour, anus or cloaca and vulva; the side apposite to the ventral is dorasal. The other two sides are right and left laterals.
Lip region: The lip region is also called as head exhibits great variation which may be used taxonomic purpose.
Tail region: It is the post-anal elongation of the body present in all stages of nematodes.
General structure of nematode: The body of nematode is tubular which may be divided into three regions I) Outer body tube or body wall II) Inner body tube –Digestive system III) Body cavity– Reproductive system, Nervous system, Excretory system
I) Outer body tube The outer body tube is comprises of (A) Exoskeleton or cuticle, (B) Hypodermis and (C) Muscle layer. (A) Exoskeleton or cuticle: It is outermost covering of body wall which is non-cellular, semipermeable and tough layer secreted by the epidermal cells. It invades all natural opening of body including the mouth, rectum, cloaca, vagina, excretory pore, amhids and phasmids. The cuticle of many nematode species has markings on the surface. They are varied and complex and often used by taxonomist in identification of nematode species. The cuticular lining/markings are categorized in different types are as follows.
Cuticular lining or markings: 1. Punctations – They are commonly appearing as minute or round areas which are arranged in pattern. It acts as a structure for strengthening cuticle and transport of proteins. 2. Transverse markings or Annules or Striations – There are several transverse lines present on the surface of cuticle. These markings are exhibit on most of the plant parasitic nematodes and often used for identification. Annulations give segmented appearance e.g. scales in Criconemoides & perineal pattern of root-knot nematodes. Necessary for dorsoventral undulatory movement.
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3. Longitudinal markings – These markings are the lines on the cuticle, which runs longitudinally throughout the nematode body. i) Ridges – These are raised areas, which run length of the body and occur on sub-median as well as lateral surface. ii) Alae – These are thickening or projections occur in lateral or sub-lateral region. They assist in locomotion. There are three types of alae Caudal alae – These are found in the posterior region and restricted to males as copulatory bursa. Cervical alae – These are confined to anterior part of the nematode body. Cervical alae are found in some species of marine nematodes. Longitudinal alae – These are limits to the lateral fields. They are transverse by striations or furrows varying in number from one to twelve which provide locomotion and may permit slight change in the width of nematode.
Cuticular layering or covering: The nematode cuticle is basically three layer structure and composed of (a) Cortical layer, (b) Median layer and (c) Basal layer. (a) Cortical layer – It is often divided into external cortical layer and internal cortical layer. The surface of external cortical layer is exposed to the environment. This layer is very thin measuring about 25 to 40 mµ. The external layer has been considered to be kertatine (protein) chemically. In cyst nematode the cuticle of the female on maturity becomes tough and leathery to form cyst which protect eggs under dry conditions. (b) Median layer – The average thickness of the median layer is 0.1 µ in the larva of Meloidogyne and Heterodera. Chemically the median layer consists of protein, which resembles collagen (Non osmophilic collagen protein). (c) Basal layer – It consist of regularly arranged vertical rods or striations. It is composed of protein with very close linkage between the molecules, resulting in resistant layer which protect the nematode from outer environment. The thickness of basal layer varies from 125 to 500 mµ (Osmophilic protein close to keratine)
Functions of cuticle: 1) Protects the nematode from harsh environment. 2) Serves as exoskeleton 3) Provide mechanism of movement of the nematode through the soil and plant tissue.
(B) Hypodermis – The hypodermis is cellular or partially cellular layer. It secretes the cuticle. It lies between cuticle and somatic muscle layer. It is important metabolic active part of the nematode. Forms 4 cords (dorsal, ventral and two laterals). Contains hypodermal glands (C) Muscle layer - It is arranged in a single layer. The muscle cells are spindal shaped and attached to the hypodermis throughout their length. It is well connected to the nervous system. The stimulation of the muscles by dorsal and ventral nerves cause contractions in the dorso-ventral plane and result in the characteristic scinusodial movement of nematode.
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On the basis of arrangement of the basic cells, following three types are identified: a. Holomyarian: Having two muscle cells in each zone. b. Meromyarian: Two or five muscle cells in each interchordal zone. c. Polymyarian: More than five muscle cells in each zone Specialized muscles: Feeding, food movement and defecation Reproduction e.g. vulvar, spicular, gubernaculum, copulatory and bursal muscles. Chemically muscle layer is made up of myosin and actin. II) Inner body tube or Digestive System: The inner body tube of nematode forms the gut or alimentary canal in which some glands are open. It is distinguishable in to three regions as: 1. Stomodaeum (Forgut) 2. Mesenteron (Midgut) 3. Proctodeum (Hindgut)
Fig. Digestive system of Nematode 1. Stomodaeum: It includes the mouth and lips, the stoma and the oesophagus. Mouth and lips: The mouth and lips are also associated with the feeding activity of the nematode. Generally, there are 6 lips (two sub dorsal, two sub ventral and two lateral) which surround the mouth. In some cases they may be reduced by partial fusion to 3 or by complete fusion to form a united ring around the mouth. Stoma or Buccal cavity: The stoma, which is also called as mouth cavity or buccal cavity forms the feeding apparatus and lies between the mouth and the oesophagus. The simple stoma is found in many bacterial feeding nematodes, takes the form of a cylindrical or triangular tube, terminating in a valve like glottoid apparatus, which may bear the minute teeth. The cuticular lining of stoma may form teeth. Plant parasitic nematodes are armed with a protrusible stylet which is usually hallow and functions like a hypodermic needle. Stylet with basal knob are called as Stomatostylet e.g.Tylenchida and the stylet without basal knob are called as odontostylet or ononiostyle e.g. Dorylaimida. Oesophagus or pharynx: The oesophagus is a muscular pumping organ attached to the posterior portion of the stylet and lined with cuticle. It is the largest part of stomodaeum and found between stoma and intestine. Internally, pharynx lined with cuticle and externally by membrane (basal lamella). It contains radial muscles, oesophageal glands and valves, which prevents the regurgitation of food. In some nematodes median and posterior part of pharynx swollen to form muscular bulb. The cylindrical oesophagus has three well defined regions are as follows.
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i) Corpus- The corpus may further divided to form pro and meta corpus, which is swollen contain muscle cells, supporting cells, nerve cells, gland cells (one dorsal and two sub ventral). ii) Isthumus iii) Basal bulb 2. Intestine or midgut: The midgut is endodermal in origin. It is simple, hallow, straight tube consisting of a single layer of epithelial cells. The intestine is generally divided in to three region which merge in to each other without any perceptible boundaries. They are anterior or ventricular region, the mid intestinal region and posterior pre-rectal region. 3. Proctodeum: The proctodeam or hind gut consist of Rectum and anus in female and cloaca in male. Rectum is cuticular linings and invaginated in to rectal gland on par in nematodes. Female nematodes consist of simple tube leading to anus, whereas reproductive system opened in to it and form cloaca in male contain spicules and other copulatory structure. Anus consists of slit structure on ventral side. The control of anus opening is by unicellular, H shaped depressor muscle, which acts by raising dorsal wall of the rectum and pulling posterior lip of anus to open it.
Glands: 1) Pharyngeal or Esophageal – There are three uninucleated glands are present. One is dorsal & other two ventro-lateral or sub ventral positions. The glands connected with lumen of oesophagus by means of terminal ampulla or swelling. Function: Hatching, host penetration and digestion 2) Rectal - Rectal glands are varies from species to species or male and female of same species. Copious production of gelatinous mucopolusaccharide matrix in the eggs of deposited as mass. Which range to protect the eggs. Function: Secretion of gelatinous matrix.
Function of Digestive system: Digestive juices which are secreted from dorsal oesophageal glands are injected into the host plant cell by means of the stylet. During feeding, a distinct zone develops around the feeding site in the host cell. There are two feeding phases- 1) Injection phase or salivation phase and 2) Ingestion phase. 1) Injection phase or salivation phase: During this phase, the flow of salivary juices into the host cell occurs due to contraction of lateral muscle of the median bulb. 2) Ingestion phase: During this phase, rhythmical contraction of the posterior part of oesophagus associated with the median bulb occurs and in some forms, the oesophageo-intestinal valve or cardia is responsible for ingestion of material from the host. Secretion- Various glands associated with digestive system. Active protein and mucopolysaccharide synthesis their product and shed through cuticle- either through cuticle lined either into stomodaeum or proctodeum. Excretion- Intestine acts as an excretory organ and defection is mechanically controlled and it is an intense process.
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III) Body cavity or Psuedocoelom: The body cavity of nematode is different from animal. The true coelomic cavity is that completely fined with mesodermal in origin. a) Coelomic cavity:- Lined externally with somatic muscle ( Mesodermal in origin) and internally by alimentary canal ( Ectodermal in origin). b) Pseudocoelomic cavity: - Lined with tissues of Mesodermal in origin. c) Pseudocoelomic fluid: - Baths all internal organs. Chemical composition of fluid- Protein, Glucose, Sodium, Phosphorus, Chloride, Potassium, Magnesium, Copper, Zinc, Iron, Hematin, Ascorbic acid with neutral pH. Body cavity of nematodes comprises Reproductive system, Nervous system and Excretory system. The Circulatory and Respiratory systems are absent in nematodes. 1. Reproductive system of nematode:- - The males are generally slightly smaller than females. - The nematodes are dioecious or amphigonus having a separate male and female within a species. - Generally the males are lesser in number than females or even be completely absent. This indicates a tendency towards hermaphroditism and parthenogenesis. A. Female Reproductive system:- Monodelphic- The nematodes may have a single ovary the female is called as monodelphic. Didelphic- The nematodes may have two ovaries then the female is called as didelphic. Prodelphic- When a single gonad is present, it may be either directed towards anterior to vulva then female is called as prodelphic. Opisthodelphic- The gonad either directed towards posterior to vulva then female is opisthodelphic. Amphidelphic- The two ovaries are opposite to one another, such as one is anteriorly directed and other posteriorly directed.
Fig. Prodelphic, Opisthodelphic and Amphidelphic
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The female reproductive system typically consists of ovary, oviduct, uterus, vagina and vulva. Vagina Ovary
Oviduct Vulva Uterus
Fig. Female Reproductive System
(i) The ovary- It is hollow elongate tube. The apical end of ovary has a cap cell at the tip which is called as germinal or zone of multiplication in which rapid cell division takes place to give rise germinal cells. This region is followed by growth zone which constitutes the greater part of ovary. The oocytes or germ cells in this zone become big and ripe which are generally arranged in single rows. After maturity they are called oogonia. (ii) Oviduct- Next to growth zone of ovary the gonad has oviduct. The oocytes when ripe they pass in to oviduct. Oviduct may serve as spermathica in some nematode. However in others, the spermathica is in the proximal part of uterus or in the post- vulvar sac at the distal end of gonad. (iii) The uterus- It is the largest and most complex part of the gonad, serves and function of fertilization, egg shell formation and laying of eggs. As started above, the upper part of uterus serves as spermathica in some nematodes. (iv) Vagina- The uterus entered in common vagina, which is a short, narrow and flattened tube lined with cuticle and provided with muscles. (v) Vulva- The vagina opens through female gonopore, the vulva. The eggs are expelled through a vulva which is normally situated middle of the body. B. Male Reproductive system:- Monarchic- The nematode may have one testis are called monarchic. Diarchic- The nematode may have two testis are called diarchic. The male reproductive system generally consists of three primordial parts: the testis, seminal vesicle, and vas deference. (i) The Testis- In the testis the germinal and growth zone can be easily distinguished. In germinal zone Spermatogonial division takes place, while in growth zone, spermatocytes increases in size. The spermatocytes are arranged in single or double rows. (ii) Vas deference- It consist of an anterior glandular region and posterior muscular region and containing the ejaculatory duct at the posterior end.
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(iii) Ejaculatory duct- The ejaculatory duct helps in the ejection of sperms during fertilization. It tapers gradually and opens ventrally into the cloca. The cloca is provided male copulatory structures such as spicules, gubernaculums etc.
2. Excretory system of Nematodes:- The excretory system is not well developed in nematodes. The excretory pore is located in midventral line close to the nerve ring. The excretory system in nematodes are two types. a. Glandular type b. Tubular type a. Glandular type:- The glandular type consist of a single specialized cell known as renette cell. It has posteriorly located enlarged gland known as excretory gland or ventral gland. This gland is connected to the excretory pore by a duct that terminates in a pouch like structure known as ampulla. This type found in members of the class Adenophorea.
Excretory Pore Excretory Duct
Excretory Gland
Fig. Glandular type b. Tubular type:- The tubular type of excretory system consists of four cuticularised canals. Two are anterior and another two are posterior canals. There is a pouch like structure in the middle which connects both the lateral canals. It is known as excretory pore. There are four types in tubular system. i) Asymmetrical or Tylenchid type ii) Inverted ‘U’ shaped or Ascarid type iii) Rhabditid type iv) Simple ‘H’ shaped or Oxyrid type i) Asymmetrical or Tylenchid type- Majority of pant parasitic nematodes which fall under the order Tylenchida have this asymmetrical tubular type excretory system. In this type a single tube runs throughout the nematode body length and found in either of the lateral hypodermal chords. In the middle of the canal, the lumen enlarges to form Fig: Asymmetrical or excretory sinus which is a nucleated structure. It opens Tylenchid type through the anterior canal by separating as a small branch tube.
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ii) Inverted ‘U’ shaped or Ascarid type- In this type three canals are found. Out of the three canals, one is located anteriorly and two are located posteriorly. The anterior canal opens outside through an excretory pore located at its tip. Fig: Inverted ‘U’ shaped or Ascarid type iii) Rhabditid type- Four cuticularised canals are present. Two are located anteriorly and another two are in posterior in
position. Excretory sinus is Fig.: Rhabditid type modified into two excretory gland in between lateral
canals. These glands open ventrally as excretory pore. v) Simple ‘H’ shaped or Oxyrid type- This type has four tubular cuticularised canals. Two canals are anterior and slightly shorter than the two canals located posteriorly. These canals are connected by a swollen excretory sinus which opens externally as Fig.: Simple ‘H’ shaped excretory pore. or Oxyrid type Functions of Excretory system:- 1. Excretions of toxic substances. 2. Secretion of certain chemicals. 3. Osmoregulation. 4. In T. semipenetrans, excretory pore secrets gelatinous matrix which bind and protect the eggs from abnormal environmental condition.
3. Nervous system of Nematodes:- In nematodes, a central nervous system and a peripheral nervous system can be described. Central nervous system- It is also known as brain consist of nerve ring associated with ganglia and nerves. The nerve ring or circum-oesophageal commissure is belt which may be broad and flat. It is present around the oesophagus in majority of nematodes. In Tylenchida it encircles the isthumus while in Dorylaimida it is present around the narrow anterior part of oesophagus. The nerve ring is placed obliquetly with dorsal side most anterior. Towards the anterior end of nerve ring six ganglia are present (2 sub-dorsal, 2 sub- ventral and 2- lateral) known as papillary ganglia which are very small in size. Towards the posterior side of nerve ring nerves arise in the dorsal, lateral and ventral side of the body. Transverse commissure connecting the nerves are also present in different regions of the body.
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Complied by Prof. T. B. Ugale & Prof. A. S. Mochi (K. K. Wagh College of Agriculture, Nashik)
Peripheral nervous system- It includes somatic nerve, cephalic papillae nerve, amphidial nerve, amphids, phasmids, dierids, hemizonid, hemizonian and other associated structures. 1) Somatic nerve: The nerves which run longitudinally in the hypodermis are called as somatic nerves. The following are different types of somatic nerves- a) Dorsal somatic nerve- Its originates from the dorsal ganglia of the posterior side of the nerve ring, goes through the dorsal chord up to anal region where it bifurgate and join the lumber ganglia. b) Latero-dorsal nerve- It is paired structure originates from the nerve ring and extend towards the posterior side in sub median position. They also innervate the muscular layer. c) Latero-ventral nerve- It originates from the nerve ring and extends posterior on sub median position. d) Ventral nerve- It is the part of central nervous system. e) Lateral nerve- It is in anal area and having lumber ganglion on each side. f) Dorso lateral nerve- Paired nerve and joins the ventro lateral nerve in anal region. 2) Cephalic papillae nerve: These nerves go through the body cavity. These are nerve fibers arising from cephalic papillae ganglion from the cephalic nerve near the lips. 3) Amphidial nerve: In above the papillary ganglia are directly connected with nerve ring, while in this case the connection is indirect i.e. through sub-ventral trunk by lateral ventro commissure. Anteriorly each amphideal nerve enters to amphideal glands and their processes (nerves) breaks up in an elongate sac, which represent the neuron, are called terminals and pouch. Sensory elements which represent the neuron are called terminals and the group of such terminal is called as sensilla. The has an amphid aperture situated either on the lips (labial) or post labial and opening to the exterior. Internally the aperture is connected to a pouch (fovea) which leads to sensilla pouch or fusus through an amphid duct or canalis amphidianlis. The sensilla pouch is connected to the amphidial nerve through the nerve process. 4) Amphids: Amphids are paired lateral sensory organs probably chemoreceptors situated in cephalic region of the nematode. The amphid aperture exhibited various shapes viz., pore like, circular hooked, stirrup-shaped, spiral etc. There may be sexual dimorphism in respect of amphids, they may be larger in males than females or may be more complex in males. 5) Phasmids: Phasmids are paired lateral sense organs, usually one on each side of tail at lateral fields. The phasmids open to the exterior through a minute pore. Internal, they possess a canal or pouch containing sensory receptors which are supplied by lateral caudal nerve. In a few nematode species they may enlarged and known as scutella. 6) Deirids: They are the paired papillae situated in the mid region of the body (oesophageal region) opposite to the excretory pore. These are sensory structures but do not have an opening to the exterior. They are also called as cervical papillae. They function as mechanoreceptors. 7) Hemizonid and Hemizonion: The hemizonid (belt or girdle) is highly refractive biconvex structure forming a semi-circle in the ventral side of the body and ending at the lateral fields, located either anterior or posterior to the excretory pore and situated between the cuticle and hypodermis. Hemizonion is small nerve commissure which is structurally identical to hemizonid and situated posterior to it.
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8) Cephalids: Like hemizonid and hemizonions cephalids are also highly refractive band like structures situated in the cuticle dorsally and ventrally, but they form a complete ring or round the body, anteriorly just behind the cephalic region. There are two pairs. Generally, the lateral epidermal chord originate at a level of posterior cephalids. 9) Caudalids: It is a small nerve commissure situated in caudal region slightly posterior to anus and linking the pre-anal ganglion to the lumber ganglion.
Fig. Anterior nervous system of nematode
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Fig. Posterior nervous system of nematode
Biology of Plant Parasitic Nematodes Under biology, the life cycle of nematode is studied. The life history of most plant parasitic nematodes is simple and direct. The basic pattern of life cycle is given bellow:- The following six stages or instars are found in the life cycle of a primitive nematode: (i) The egg (ii) The first stage larva or juvenile (L1) (iii) The second stage larva or juvenile (L2) (iv) The third stage larva or juvenile (L3) (v) The fourth stage larva or juvenile (L4) (vi) The adult . i) The Egg: The egg of most of the nematodes is similar in shape (oval) and size irrespective of the adult nematode. The eggs are covered by three membranes, a) The external protein layer- It secreted by uterus wall. b) The middle chitinous layer or true shell- It secreted by egg itself. c) The inner lipid layer- It is soluble in various dehydrating agents and made up of protein and lipid. These three layers are not found in most of the Tylenchids. The amount of chitin in chitinous layers differs in different species of nematodes.
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Complied by Prof. T. B. Ugale & Prof. A. S. Mochi (K. K. Wagh College of Agriculture, Nashik) ii) Embryonic development: After discharge of egg by female, it starts dividing by cleavage of their protoplasm’s to form cells. The first cleavage occurs transverse to the longitudinal axis and gives two equal cells or blastomeres which are the first somatic (S1) cell and the parental germinal (P1) cells. The second cleavage results in four cells which are first arranged in a ‘T’ shape. This shape achieved by the blastomere S1 dividing longitudinally and blastomere P1 dividing transversally by P2 and S2. At last these cells get arranged in rhomboidal shape. The transverse and longitudinal mitotic division of daughter cells continues. The S1 blastomere is the primary somatic cell and its two products (A & B) produce most of the nematodes ectodermal cells. The S2 blastomere produces somatic tissues and gives rise to ectoderm (E), mesoderm (M) and stomoderm (St) tissues. The gonads of nematode are derived from P1. In the blastula stage the cells are so arranged as to form a fluid filled sphere bound by a single layer of the cells, while in the gastrula stage, the early embryo consist of an open mouthed sac-like body with a wall of two layers of cells. The cells A and B further divide to produce a, band P2 divide to give P3 and S3. The dorsal cells produced by A and B continue to divide and finally give to most of the hypodermis, excretory cells and nervous system. The daughter cells P2 divides into P4 and S4. These S3 and S4 are ectodermal and produce the hypodermis in the posterior region of nematodes body.
The ectodermal tissue is produced from the products of cell E1 and P1 divides into P5 and S5. The descendants of S5 give rise the epithelium which covers the gonads and their ducts while the products of P5. G1 and G2 and their descendants proliferate germ cells only. The primary mesodermal cells M gives rise the nematodes body wall musculative and its Pseudocoelomic cells, while the pharynx from St cells. During early embryonic stages, these primary cells St, M and E present on ventral surface of the embryo and are taken within the dorso-ventrally flattened and anterior-posteriorly directed embryo is changed to cylindrical shape. The embryo starts to become worm- shaped and coiled larva is recognized inside the egg membrane. At last the cell constancy is reached and further cell multiplication stops in all organs except the reproductive system. In plant parasitic nematodes the stylet is also present. ii) Post-embryonic development: The post embryonic development in plant parasitic nematodes takes place within the egg leading to the formation of larva which is ready to undergo first moult. In the process of post embryonic development, the organ differentiation, hatching and moulting are the important stages. iii) Hatching: Hatching occurs in response to stimuli from host or it take place under favorable environment. In cyst forming nematodes, the release of larva from cyst is an emergence not hatching. Egg have hatched within the cyst. The egg of Globodera rostochinensis generally hatch in response to root exudates (stimuli) provided by the solanaceous crop viz., Potato and tomato. After embryonic development the first stage larva are found within the egg. After reaching a particular stage of growth and hatching condition are present, the larva sows vigorous movement, often causing bulging of the egg membrane as seen in case of Pratylenchus, Paratylenchus, Nacobbus and Meloidogyne. After that the larva makes a series of thrusts with the help of stylet on the egg shell @ 40-90 per minute.
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iv) Moulting (Exclusion): The growth in nematode is associated with moulting which usually occurs four times and there are five stages. After the fourth moult the nematode become full grown adult. During moulting, the entire cuticle, including the cuticular lining of stoma, stylet, oesophagus, vulva, cloaca, rectum, amphids, phasmids and excretory pore is shed. In most plant parasitic nematodes greatest growth occurs after the last moult and moulting tends to occur in the earlier half of the growth curve. v) The stimulus: It is reported that the neurosecretory cells of nematodes are stimulated to produce some secretions which activate glands that produce enzymes or hormones which initiate moulting. In some cases root exudations act as stimulus e.g. in case of Pratylenchus nanus root exudes will act stimulus during 4th moult. In endoparsitic nematodes of plants, the stimulus may be more complex and may be closely associated with an increase in size of nematode, because in these nematodes moulting does not occur until some growth has completed within the host. The receptor may function as stretch receptor in this case. It is well association with neirosecretory cell which leads to production of enzyme which initiates the moulting. The nematode cuticle may shed in one piece in Pratylenchus the lining of amphids; oesophagus, excretory duct phasmid and rectum are shed with moult. Prior to moulting the hypodermis increase in thickness due to accumulation of ribosome and protein.
Significance of Life History: 1. Life cycle of nematodes should be understood, when control measures are considered. 2. The wheat gall nematode may effectively control by crop rotation with non-host plant. 3. Emergence of larva from gall is virtually complete when soil moisture and temperature between favorable. 4. Larvae die when they are outside the gall in absence of host.
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Complied by Prof. T. B. Ugale & Prof. A. S. Mochi (K. K. Wagh College of Agriculture, Nashik)
LECTURE NO. : - 4 CLASSIFICATION OF NEMATODE (Taxonomic)
Phylum- Nematoda ______Class- Adenophorea Class- Secernentea
Sub-class: Enoplia Sub-class: Chromatorea
Super Order: Marenoplica Super Order: Terrenoplica
Order: Enoplida Order: Dorylaimida Order: Araeolaimida Oncholaimida Isolaimida Chromadorida Tripylida Mononchida Desmoscolecida Stichosomida Desmodorida Monhysterida
Class- Secernentea
Sub-class: Rhabditia Sub-class: Spiruria Sub-class: Diplogasteria
Order: Rhabditida Order: Ascaridida Order: Spirurida Family Family Family Heterorhabditidae Ascarididae Drocunculidae Steinernrmatidae Dictophymatidae Filariidae
Order: Tylenchida Order: Diplogasterida Family Diplogasteridae
Sub-order: Tylenchina Sub-order: Aphelenchina Sub-order: Sphaerulariina Family- Aphelenchina Family- Fergusobiidae
Super family: Tylenchoidae Super family: Criconematoidae Family: Anguinidae, Belonolaimidae Family: Criconematidae Dolichodoridae, Heteroderidae Tylenchulidae Tylenchidae, Hoplolaimidae
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Complied by Prof. T. B. Ugale & Prof. A. S. Mochi (K. K. Wagh College of Agriculture, Nashik)
LECTURE NO. : - 5 ECOLOGICAL CLASSIFICATION OF NEAMATODE (BY HABITAT)
There are two major classes I. Above ground feeder II. Below ground feeder I. Above ground feeder a. Feeding on flower buds, leaves and bulbs i) Seed gall nematode: Anguina tritici ii) Leaf and bud nematode: Aphelenchoides iii) Stem and bulb nematode: Dictylenchus b. Feeding on tree trunk i) Red ring nematode: Rhadinaphelenchus cocophilus ii) Pine wilt nematode: Bursaphelenchus xylophilus II. Bellow ground feeder It is again classified in to three classes I) Endoparasitic nematodes II) Semiendoparasitic nematodes III) Ectoparasitic nematodes a) Endoparasitic nematodes The entire nematode is found inside the root and the major portion of nematode body found inside the plant tissues. They are two types 1) Migratory endoparasite: - These nematodes move in cortical parenchyma of host root. While migrating they feed on cells, multiply and cause necrotic lesion. Example, Pratylenchus spp., Radopholus spp. and Hirschmanniella spp. 2) Sedentory endoparasite: - the second stage larvae penetrate the root lets and become sedentary throughout the life cycle, inside the root cortex. Examples, Heterodera spp. and Meloidogyne spp. b) Semiendoparasitic nematodes The anterior part of nematode, head and neck being permanently fixed in the cortex and the posterior part extends free into the soil. Examples, Rotylenchulus reniformis and Tylenchulus semipenetrans. c) Ectoparasitic nematodes These nematodes live freely in the soil and move closely or on the root surface, feed intermittently on the epidermis and root hair near the root tip. They are two types, 1) Migratory ectoparasites:- These nematodes spend their entire life cycle free in the soil, feeding externally on the host plants, deposit eggs in soil. When the roots are disturbed they detach themselves. Examples, Criconemoides spp., Paratylenchus spp. and s spp., etc. 2) Sedentory ectoparasites:- In this type of parasitism the attachment of nematode to the root system is permanent but for this, it is similar to the previous one. Examples, Hemicycliophora arenaria and Trichodorus spp., etc.
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Diagnostic characters of class Secernentea and Class Adenophora Sr. Class- Secernetea Class- Adenophorea No. Amphidial opening is on the head near 1 Amphids open behind the head. the lip region. Lateral canals open into the excretory Lateral canals & excretory duct end in a 2 duct. cell. Oesophagous is divided into Oesophagous is cylindrical with an 3 procorpus, mediun bulb, isthumus & enlarged base. labial bulb. Male tail lacks bursa but possess genital 4 Male tail with bursa (caudal alae) papillae. 5 Caudal glands are absent. Caudal glands are present. The mesenterial tissues are less 6 The mesenterial tissues are well developed. developed.
Differences between sub-order Tylenchina and sub-order Aphelenchina Character Tylenchina Aphelenchina Lip Varying in shape Set-off Annules Faint to strong annules. Faint annules. Well developed; one dorsal & two Weekly developed; no stylet Stylet sub ventral knob. knob. Three parted with square shaped Oesophagous Three parted medium bulb. Gland opening Behind the stylet knob in procorpus Open in the mediun bulb. One or two ovary, vulval position Female Single ovary; vulva posterior. vary. Male Bursa present Bursa rare Weak to strong sclerotization is Spicule Rose thorne shape spicule present. seen with gubernaculums
Differences between family Tylenchoidea and family Criconematoidea Character Tylenchoidea Criconematoidea Lips are hexaradiate, labial frame Labial region is poorly developed, Labial region work present. labial plate present. Criconematoid type stylet; long Conus, shaft and knobs are variable Stylet and anchor shape knob which lies in shape in base of metacarpus. Pro and metacarpus amulgameted Narrow procarpus, round to a single unit, short isthumus, Oesophagous metacarpus with vaue, isthumus the post carpus reduced, appears followed by glandular basal bulb. as ‘set-off’, smaller than pro & metacarpus. Deirids Present (2 pair) Absent Single or two ovary post uterine sac Single ovary with posterior vulva; Female gonad (PUS) is present. PUC absent. Male gonad Single testis, caudal alae is preset. Single testis; caudal alae rare. Phasmid Eratically present in tail region. Not known.
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Complied by Prof. T. B. Ugale & Prof. A. S. Mochi (K. K. Wagh College of Agriculture, Nashik)
LECTURE NO. : - 6 IMPORTANT PLANT PARASITIC NEMATODES
1) Root-knot Nematode, Meloidogyne spp. Systematic Position:- Order - Tylenchida Sub order - Tylenchina Super family - Tylenchoidea Family - Heteroderidae Sub family - Meloidogyninae Genus - Meloidogyne Species - i) incognita ii) javanica iii) arenaria iv) hapla Parasitism & Habitat:- i) Females and III & IV stage of larvae are Sedentory endoparasites. ii) Males and II stage larvae are migratory. Morphological characters:- i) Body - Elongate larvae and male typically saccate, spheroid with a distinct neck in females. ii) Stylet - In males, Strong with rounded knob & in females, more slender than males. iii) Oesophagous - With large median bulb followed by short isthumus. iv) Excretory pore - Often seen with part of excretory tube in the area between posterior part of stylet knobs and opposite to median bulb. v) Vulvas & anus - Females typically opposite to neck and surrounded by a pattern of fine lines like human fingerprint.(Perennial pattern) vi) Spicule - Very near the terminus of males Bursa is
absent. Symptoms:- - Yellowing of leaves - Stunted growth - Reduced vigor - Reduced size & number of fruits - Gall formation
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Complied by Prof. T. B. Ugale & Prof. A. S. Mochi (K. K. Wagh College of Agriculture, Nashik)
- Multinucleate cell – Giant cell (Nurse Cell) - Hypertrophy – Enlargement of cell - Hyperplasia – Multiplication of cell Control:- - Two to three deep Ploughing - Rotation with cereal crops - Apply carbofuron (Furdan 3G) @ 7 g/m2 - Resistant varieties of Tomato eg. Hisar Lalit, PNR 7
2) Reniform Nematode, Rotylenchulus reniformis Systematic Position:- Order - Tylenchida Sub order - Tylenchina Super family - Hoplolaimoidea Family - Hoplolaimidae Sub family - Hoplolaiminae Genus - Rotylenchulus Species - reniformis
Parasitism & Habitat:- Females are Semiendoparasitic on many plants. Morphological characters:- i) Body - Males and immature females are slender and small, adult females are kidney shaped ii) Oesophagous - Dorsal oesophageal glands opens about one stylet length posterior to stylet knobs. Symptoms:- Yellowing of leaves, delayed germination, reduced plant growth and vigor, stunted growth, browning of roots due to penetration of nematode are the general symptoms of this nematode. Young and tender plants are more vulunerable to nematode attack.
3) Root-lesion Nematode, Pratylenchus spp. Systematic Position:- Order - Tylenchida Sub order - Tylenchina Super family - Tylenchoidea Family - Pratylenchidae Sub family - Pratylenchinae Genus - Pratylenchus
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Species - i) coffeae - Citrus, Banana & coffee ii) zeae - Maize iii) thornei - Pulses Parasitism & Habitat:- - Migratory endoparasites - Feeding on root cortex of many crop/plant - All stages found in root or soil. Morphological characters:- i) Body length - 0.4-0.8 mm. ii) Lip region - Slightly set-off from body. iii) Stylet - Typically short, strong with massive knob. iv) Ovary - Monodelphic v) Vulva - Posterior fourth of the body (75-80%). vi) Tail - Nearly round to pointed and in males, the tail has bursa. Symptoms:- Late emergence of seedlings, less germination and stunted growth with necrotic lesions on the root surface which are initially small coalesce at the later stage and cause death of the rootlets. Root system is reduced Control:- - Raise nursery in nematode free soil - Pull and burn infected plants
4) Spiral Nematode, Helicotylenchus spp. Systematic Position:- Order - Tylenchida Sub order - Tylenchina Super family - Tylenchoidea Family - Hoplolaimidae Sub family - Rotylenchoidinae Genus - Helicotylenchus Parasitism & Habitat:- Endoparasitic and ectoparasitic on many plants Morphological characters:- i) Body - Arcuate to ‘C’ shape when relaxed ii) Stylet - Moderately long, typically located more than one half stylet length posterior to stylet knobs. iii) Ovaries - Two (didelphic) iv) Vulva - Posterior to middle of body (60-70%) v) Tail - In females, rounded to nearly pointed often with short projection on ventral side and In males, tail is short with bursa. Symptoms: - The nematodes attack root cortex and produce necrotic lesions.
5) Cyst Nematode, Heterodera spp & Globodera spp. Cyst means any abnormal membranous sac or blister like pouch containing fluid. Systematic Position:- Order - Tylenchida Sub order - Tylenchina Super family - Tylenchoidea Family - Heteroderidae Sub family - Heteroderinae
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Complied by Prof. T. B. Ugale & Prof. A. S. Mochi (K. K. Wagh College of Agriculture, Nashik)
Genus - i) Heterodera ii) Globodera Species of Heterodera - i) avenae - Cereal cyst nematode(wheat & barley) found in north India ii) zeae - Maize cyst nematode iii) cajani - Pigeon pea cyst nematode (tur, mung, Udid & cowpea) iv) oryzicola - Rice cyst nematode (rice & banana) found in Kerala, M.P., Orissa & West Bengal. Species of Globodera - i) rostochinensis - Potato cyst nematode or Golden nematode ii) pallida Host plants - Potato, Tomato & Brinjal Parasitism & Habitat:- Parasitic on many plants mostly in temperate zone (Notably potatoes, sugar beets, oats & other grains, clover, soybean & various cruciferous) Morphological characters:- i) Body - Slender in males (1.0-2.0 mm) and larvae (0.3-0.6 mm) In females, typically swollen, lemon shaped (0.5-0.8 mm) ii) Colour - White or yellow, cyst dark brown, lemon shaped (0.8 mm long & 0.5 mm wide) or nearly same shape as that Meloidogyne female. iii) Stylet - Short in males with rounded basal knobs & in larvae, more than 0.02 mm long. iv) Oesophagous - With well-developed median bulb & lobe extending back & overlapping the intestine. v) Spicule - Near the posterior end of males Globodera - Similar to Heterodera spp. slight difference in adult females are globular (rounded) in shape and hence the genus is named as Globodera. Symptoms:- Heterodera - The diseased plants show yellowing of leaves, stunted growth, reduced tillering. Earheads if formed are very small known as ‘Molya’ disease’ Globodera - Typical symptoms of heavy infestation are stunted plants with unhealthy foliage, premature yellowing, poor development of root system, reduction in size and number of tubers. Such plants exhibit temporary wilting during hotter part of the day. Control:- Heterodera - Two- three summer ploughing at 10-15 days interval. - Rotation with Mustard, chick pea - Apply Carbofuron @ 1-2 kg a.i./ha. Globodera - Rotation with pea, cabbage, carrot, cauliflower during autumn season. - Grow resistant varieties of potatoes - Kufri Swarna, Kufri Thenmalai
6) Daggar Nematode, Xiphinema spp. Systematic Position:- Order - Dorylaimida Sub order - Dorylaimina Super family - Dorylaimoidea Family - Longidoridae Sub family - Xiphineminae
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Complied by Prof. T. B. Ugale & Prof. A. S. Mochi (K. K. Wagh College of Agriculture, Nashik)
Genus - Xiphinema Parasitism & Habitat: - Migratory ectoparasites
Morphological characters:- i) Body - Females elongate, cylindrical, forming open spiral with a greater curvature in posterior half. ii) Stylet - Typically long.. iii) Ovaries - Monodelphic or didelphic. iv) Vulva - Situated at middle of body. v) Tail - Bluntly rounded or with projections on ventral side in both males and females. vi) Males extremely rear, not essential for reproduction. Symptoms: - Attacked roots show necrosis, lack of laterals, terminal swelling, root galling etc.
7) Rice stem Nematode, Dictylenchus angustus Systematic Position:- Order - Tylenchida Sub order - Tylenchina Super family - Tylenchoidea Family - Anguinidae Sub family - Anguininae Genus - Dictylenchus Species - angustus Morphological characters:- i) Body - Females swollen, when relaxed ‘C’ shaped. ii) Stylet - Small with delicate knob. iii) Oesophagous - Basal oesophageal bulb not overlapping the intestine, cardia absent. iv) Vulva - Situated in posterior region of body. v) Ovary - Single Prodelphic. vi) Tail - Elongate. vii) Males similar to females but more slender caudal alae subterminal. Disease Caused:- Alfa disease of Rice. Symptoms:- At vegetative phase, yellowing or white splash pattern of leaf sheath where margins become concorted. Later splash patterns develop brownish stains and internodes and stems turn black. At the reproductive phase, the nematode collects around the floral primordia and feed upon the developing earheads. Earheads emerges as crinkled or twisted with empty spiklets (ripe ufra) or does not emerge at all (swollen ufra).
8) Citrus Nematode, Tylenchulus semipenetrans Systematic Position:- Order - Tylenchida Sub order - Tylenchina Super family - Criconematoidea Family - Tylenchulidae Sub family - Tylenchulinae Genus - Tylenchulus Species - semipenetrans
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Parasitism :- Endoparasitic on roots of citrus and other plants. Mature females are semiendoparasitic. Morphological characters:- i) Body - Small all stages. Mature females swollen. ii) Stylet - Small in larvaes and males, well developed in mature females. iii) Oesophagous - With distinct posterior bulb in larvae young males and immature females. iv) Vulva - Prominent in posterior end of young and adult females. v) Excretory pore - Typically situated posteriorly in protuberance just anterior to vulva. vi) Anus - Absent or difficult to see in immature stages. vii) Bursa - Absent. Symptoms:- The diseased trees show reduction in growth and vigor with yellowing of leaves. Such trees show gradual dieback symptoms starting from the uppermost portion. Roots of infected trees appear larger in diameter and darker than the healthy trees mainly due to adherence of soil particles to the gelationous matrix excreted by the adult females. Cortex of highy infested feeder roots decays and gets sloughed off easily.
9) Burrowing Nematode, Radopholus similis Systematic Position:- Order - Tylenchida Sub order - Tylenchina Super family - Tylenchoidea Family - Pratylenchidae Sub family - Pratylenchinae Genus - Radopholus Species - similus Parasitism: - Endoparasitic on roots of Banana and citrus. Morphological characters:- i) Body - 0.4-0.9 mm in length. ii) Lip - Rounded in females, set off and knob like in males. iii) Stylet - Short and stout in females, slender and rudimentary in males. iv) Oesophagous - Forming a lobe, dorsally overlaps to intestine. v) Vulva - Located at middle of the body. vi) Ovaries - Didelphic vii) Tail - Blunt end in females and male long tail with bursa. Symptoms:- In banana, bearing plants show poor growth and small fruit size, prone to toppling over under high wind pressure. The nematode causes wounding of roots resulting in reddish brown cortical lesions which are clearly visible by splitting the affected roots longitudinally. Purplish streaks on the young roots. The lesions lead to the formation of tunnels and cavities in the roots. The infection spreads to young suckers also in which necrotic tissues develop.
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LECTURE NO. : - 7 Symptoms Caused by Nematodes Most of the plant parasitic nematodes affect the root portion of plants except Anguina spp, Aphelenchus spp, Aphelenchoides spp, Ditylenchus spp, Rhadinaphelenchus cocophilus and Bursaphelenchus xylophilus. Nematode suck the sap of the plants with the help of stylet and causes leaf discolouration, stunted growth, reduced leaf size and fruits and lesions on roots, galls, reduced root system and finally wilting.
Symptoms of nematode disease can be classified as
A) Symptoms produced by above ground feeder nematodes B) Symptoms produced by below ground feeder nematodes
A) Symptoms produced by above ground feeder nematodes i) Dead or devitalized buds – Nematode infection kills growing buds e.g. Aphelenchoides fragariae on strawberry. ii) Crinkled stems and foliage - e.g. Wheat gall nematode, Anguina tritici Ulfa disease of rice, Ditylenchus angustus. iii) Seed galls – e.g. Wheat gall nematode, Anguina tritici larva enter into the flower primordium and develops in to a gall. iv) Necrosis & discolouration – e.g. Red ring disease of coconut, Rhadinaphelenchus cocophilus. Due to the infestation, red coloured circular area appear in the trunk of infested palm. v) Leaf lesions - Symptom on broad-leafed foliage plants. e.g. Chrysanthemum foliar nematode, Aphelenchoides ritzemabosi vi) Twisting of leaves and stem: e.g. In onion basal leaves become twisted when infested with Ditylenchus dipsaci. vii) Leaf discolouration: The leaf tip become white in rice due to rice white tip nematode Aphelenchoides besseyi.
B) Symptoms produced by below ground feeder nematodes The nematode infest and feed on root portion and exhibit symptoms on below ground plant part as well as on the above ground plants parts and they are classified as I) Above ground symptoms II) Below ground symptoms I) Above ground symptoms:- i. Stunting: Reduced plant growth and the plant cannot able to withstand in adverse conditions. Patches of stunted plants appears in the field. e.g. Heterodera avenae – Molya disease in wheat & barley. Globodera rostochiensis – Golden nematode in potato ii. Discolouration of foliage: Also due to nutritional deficiency e.g. Root lesion nematode, Pratylenchus coffeae White tip nematode, Aphelenchoids besseyi Citrus nematode, Tylenchulus semipenetrans
iii. Wilting: e.g. Root-knot nematodes, Meloidogyne spp iv. Decline and die back: eg. In banana decline and die back are caused by Radopholus similis.
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II) Below ground symptoms:- i. Root galling: e.g. Meloidogyne spp. – Characteristic galls on host roots Nacobbus spp – Larger galls on beet & tomato Ditylenchus radicicola – Small galls on cereals. Hemicycliophora arenaria – Galling on lemon roots Xiphinema diversicaudatum - Galling on roses ii) Reduced root system: Due to nematode feeding the root tip growth is arrested and the root produced branches. This may be of various kinds such as coarse root, stubby root and curly root. a) Stubby roots – Stubby branches or rootlets arranged in cluster eg. Trichodorus christiei on corn b) Coarse root – Lateral roots stopped growth with no branches e.g. Belonolaimus longicaudatus on corn. c) Curly root – The nematode retard the elongation of roots and cause curling of roots known as ‘Fish hook’ symptom. Eg. Injury caused by Xiphinema spp. iii) Root lesions – Necrotic lesions e.g. Pratylenchus spp (soybean), Radopholus similis (citrus & banana), Helicotylenchus multicinctus (banana) iv) Rotting – Nematode + Micro-organisms. e.g. Ditylenchus destructor – potato rot. v) Excessive root branching – e.g. Meloidogyne hapla in tomato
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LECTURE NO. : - 8 INTERACTION OF NEMATODES WITH MICRO-ORGANISMS Plant parasitic nematodes favor the establishment of secondary pathogens viz., fungi, bacteria, virus etc. The nematodes alter the host in such a way that the host tissue becomes suitable for colonization by the secondary pathogens. The nematode cause mechanical injury which favors the entry of microorganisms. The association of nematode and pathogen break the resistant in resistant cultivar of crop plant.
Nematode - Fungus Interaction Nematode - fungus interaction was first observed by Atkinson (1892) in cotton. Fusarium wilt was more severe in the presence of Meloidogyne spp. Since then the nematode - fungus interaction had received considerable attention on important crops like banana, cotton, cowpea, brinjal, tobacco and tomato. Some examples of nematode - fungus interaction are given in the following table.
Name of Role of Crop Nematode Fungus the disease nematode Damping Meloidogyne incognita Rhizoctonia solani Assist off Meloidogyne incognita Pythium debarynum M. incognita Fusarium oxysporrum Assist Cotton Vascular F. vasinfectum wilt Fusarium oxysporrum Rotylenchulus reniformis Assist F. vasinfectum Dampink Meloidogyne incognita Pythium debarynum Assist off Meloidogyne incognita Alternaria tenuis Tobacco Fusarium oxysporrum Vascular Meloidogyne incognita Fusarium parasitica Assist wilt Meloidogyne incognita
Vascular Fusarium oxysporrum Banana Radopholus similis Essential wilt Cortical rot Globodera rostochinensis Rhizoctonia solani Assist Tomato Vascular Meloidogyne spp. Fusarium oxysporrum Assist wilt Damping Ditylenchus destructor Ppytophthora infestans Assist off Potato Globodera rostochinensis Rhizoctonia solani Cortical rot Assist Globodera rostochinensis Verticillium dahliae Damping Onion Ditylenchus dispaci Botrytis allii Assist off Vascular Brinjal Pratylenchus penetrans Verticilllium dahliae Assist wilt Vascular Pratylenchus spp. Fusarium oxysporrum Assist Pea wilt Pratylenchus penetrans Fusarium pisi Assist Damping Meloidogyne javanica Rhizoctonia solani Assist off Soybean Vascular Heterodera glycines Fusarium spp. Assist wilt Vascular Cow pea Meloidogyne javanica Fusarium oxysporrum Assist wilt Stem rot Anguina tritici Dilophospora alopecuri Essential wheat Wheat rot Heterodera avenae Rhizoctonia solani Assist
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Nematode - Bacterium Interaction Nematode - bacterium interaction comparatively fewer than the nematode - fungal interactions. Some examples of nematode - bacterium interactions are presented in the following table.
Name of Role of Crop Nematode Bacteria the disease nematode Wheat Tundu Anguina tritici Clavibactor tritici Essential Vascular Pseudomonas Tobacco Meloidogyne incognita Assist wilt solanacearum Vascular Meloidogyne hapla Pseudomonas Assist wilt Meloidogyne incognita solanacearum Tomato Pseudomonas Helicotylenchus nannus Assist solanacearum Canker Meloidogyne incognita Clavibactor michiganens Assist Vascular Pseudomonas Potato Meloidogyne spp. Assist wilt solanacearum
Nematode - Virus Interaction In nematode - virus complex, nematode serves as a vector. Numerous virus- nematode complexes have been identified after the pioneer work by Hewit, Raski and Goheen (1958) who found that Xiphinema index was a vector of grapevine fan virus. Xiphinema, Longidorus, Paralongidorus spp. transmits the ring spot viruses called NEPO derived from nematode transmitted polyhedral shaped particles. Trichodorus spp. and Paratrichodorus spp. transmitted rattle virus called NETU derived from nematode transmitted tubular shape virus particles. All these nematodes have modified bottle shape oesophagus.
NEPO Virus Nematode Arabis mosaic Xiphinema diversicaudatum X. paraelongatum Grapevine fan leaf X. index Grapevine yellow mosaic X. index Tobaco ring spot X. americanum Cowpea mosaic X. basiri Tomato black ring, beet ring spot L. elongates Tomato black ring, lettuce ring spot L. attenuatus NETU Virus Nematode Tobacco rattle Paratrichodorus P. allius, P. nanus P. porosus, P. teres Trichodorus christei T. primitivus, T. cylindricus T. hooperi T. minor, T. similes Pea early browning P. anemones, P. pachydermus P. teres, T. viruliferus The nematodes acquire and transmit the virus by feeding required little one day. Once acquired it persist for longer time in nematode body e.g. Grapevine fan leaf virus will exist upto 60 days in X. index.
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LECTURE NO. : - 9 DIFFERENT METHODES OF NEMATODE MANAGEMENT Plant parasitic nematodes can be controlled by several methods. In view to keep the nematode population below economic threshold level. The management tactics should be profitable and cost effective. It is essential to calculate the benefit ratio before adopting control measures.
The nematode control methods are
1) Cultural control
2) Physical control
3) Biological control
4) Chemical control
5) Regulatory (Legal) control
LECTURE NO. : - 10 CULTURAL CONTROL
Cultural nematode control methods are Agronomical practices employed in order to minimize nematode problem in the crops.
Selection of healthy seed material:
In plants, propagated by vegetative means we can eliminate nematodes by selecting the vegetative part from healthy plants. The golden nematode of potato, the burrowing, spiral and lesion nematodes of banana can be eliminated by selecting nematode free plant materials.
Adjusting the time of planting:
Nematode life cycle depends on the climatic factors. Adjusting the time of planting helps to avoid nematode damage. When the crops planted in winter the soil temperature is low and at that time the nematodes can not be active at low temperature.
Fallowing:
Leaving the field without cultivation, preferably after ploughing helps to expose the nematodes to sunlight and the nematode die due to starvation without host plant. This method is not economical.
Deep summer ploughing:
During the onset of summer, the infested field is ploughed with disc plough and exposed to hot sun, which intern enhances the soil temperature and kills the
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Complied by Prof. T. B. Ugale & Prof. A. S. Mochi (K. K. Wagh College of Agriculture, Nashik) nematodes. For raising small nursery beds for vegetable crops like tomato and brinjal seed beds can be prepared during summer, covered with polythene sheet which enhances the soil temperature by 5 to 100C which kill nematodes in seed bed.
Manuring:
Raising green manure crops and addition of more amounts of farm yard manure, oil cakes of neem and castor, press mud and poultry manure etc. enriches the soil and further encourages the development of predacious nematodes like Mononchus spp. and also other nematode antagonistic microbes in the soil which checks the parasitic nematodes in the field.
Flooding:
Flooding can be adopted where there is an enormous availability of water. Under submerged conditions, anaerobic condition develops in the soil which kills the nematodes by asphyxiation.
Trap cropping:
Two crops are grown in the field, out of which one crop is highly susceptible to the nematode. The nematode attacks the susceptible crop. By careful planning, the susceptible crop can be grown first and then removed and burnt.
Antagonistic crops:
Certain crops like mustard, marigold and neem etc. have chemicals or alkaloids as root exudates which repel or suppress the plant parasitic nematodes.
In marigold (Tagetes spp.) plants the α – terthinyl and bithinyl compounds are present throughout the plant from root to shoot tips. These chemicals kill the nematodes.
Removal and destruction of infested plants:
Early detection of infested plants and removal helps to reduce nematode spread. After harvest the stubbles of infested plants are to be removed. In tobacco, the root system is left in the field after harvest. This will serve as a inoculation for the next season crops.
Use of resistant varieties:
Nematode resistant varieties have been reported from time to time in different crops. Nemared, Nematex, Hisar Lalit and Atkinson are tomato varieties resistant to Meloidogyne incognita. The potato variety Kufri Swarna is resistant to Globodera rostochiensis.
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LECTURE NO. : - 11
PHYSICAL CONTROL
It is very easy to kill the nematodes in laboratory by exposing the nematodes to heat, irradiation and osmotic pressure etc. But it is extremely difficult to adopt these method in field conditions. These physical treatment may be hazardous to plant or the man working with the treatments and the radiation treatments may have residual effects.
Heat: a) Heat treatment of soil: Sterilization of soil by allowing steam is a practice in soil used in green house, seed beds and also for small area cultivation. Insects, weed seeds, nematodes, bacteria and fungi are killed by steam sterilization. In such cases steam is introduced into the lower level of soil by means of perforated iron pipes buried in the soil. The soil surface needs to be covered during steaming operation. Plastic sheets are used for covering. In the laboratory and for pot culture experiments autoclaves are used to sterilize the soil.
b) Hot water treatment of planting material: Hot water treatment is commonly used for controlling nematodes. Prior to planting the seed materials such as banana corms, onion bulbs, tubers, seed and roots of seedlings can be dipped in hot water at 50-550C for 10 minutes and then planted.
Irradiation: Irradiation also kill the nematodes. Cyst of Globodera rostochiensis exposed to 20,000γ contained only dead eggs and at 40,000 γ exposure, the eggs lost their contents.
Osmotic pressure: Feder (1960) reported 100% nematode mortality when sucrose or dextrose was added to nematode infested soil @ 1 to 5% by weight. But this method is not practical and economical.
Washing process: Plant parasitic nematodes are often spread by soil adhering to potato tubers, bulbs and other planting materials. Careful washing of such material helps to avoid the nematodes in spreading in new planting field.
Seed cleaning: Modern mechanical seed cleaning method have been developed to remove the seed galls from normal healthy wheat seeds.
Ultrasonic: Ultrasonic have little effect on Heterodera spp. The use of this ultrasonic is not practically feasible
.
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LECTURE NO. : - 12 BIOLOGICAL CONTROL Biological control aims to manipulate the parasites, predators and pathogens of nematodes in the rhizosphere in order to control the plant parasitic nematodes. Addition of organic amendments such as farm yard manure, oil cakes, green manure and pressmud etc. encourages the multiplication of nematode antagonistic microbes which intern check the plant parasitic nematodes. The addition of organic amendments acts in several ways against the plant parasitic nematodes. Organic acids such as formic, acetic, propionic and butyric acids are released in soil during microbial decomposition of organic amendments. Ammonia and hydrogen sulphide gases are also released in soil during decomposition. These organic acids and gases are toxic to nematodes. Organic amendments improve soil conditions and help the plants to grow. The organic matter also provides nutrition for the crops plants.
Predacious Nematodes: Predacious nematodes have specialized open stoma armed with teeth to catch and swallow the plant parasitic nematodes. Addition of organic amendments helps to encourage the multiplication of predacious nematodes such as Mononchus spp. Other genera like Diplogaster spp. and Tripyla spp. are also come under the group of predacious nematodes.
Predacious Fungi: Most of the predacious fungi comes under Moniliales and Pjycomycetes. There are two types of predacious activities among these fungi. They are nematode a) Trapping fungi and b) Endozoic fungi
a) Trapping fungi: The nematode trapping fungi have adhesive networks and sticky knobs produced by the mycelium to capture the plant parasitic nematodes. The nematode trappers are grouped as follows. Sticky branches: The fungal mycelia have short lateral branches and they anastomose to form loops. The nematode trapped in this loops. Sticky networks: The mycelium curls around and anastomoses with similar branches. These loops produce complex three dimensional structures. The adhesive surface of network helps to hold the nematode e.g. Arthrobotrys spp. Sticky knob: Small spherical or sub spherical lobes are present on one or two celled lateral hyphae. Only the terminal knob is sticky to hold the nematodes e.g. Monacrosporium ellipsospora. Constricting ring: The short hyphal branch curls back on itself and anastomoses and forming a ring. When the nematode enters the ring and contact the inner walls of the ring cells bulge inward filling the lumen of the ring and kills the nematode e.g. M. bembicoidesd and Dactylaria brachophaga. Non-constricting rings: The trap is formed similar to the constricting ring. The ring becomes an infective structure and kills the nematode e.g. Daclyaria candida. In addition to formation of traps and adhesive secretions, the predacious fungi may also produce toxin which kill the nematodes.
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b) Endozoic fungi: The endozoic fungi usually enter the nematode by a germ tube that penetrates the cuticle from a sticky spore. The fungal hyphae ramify throughout the nematode body, absorb the contents and multiply. The hyphae then emerge from dead nematode. Catenaria vermicola often attacks sugarcane nematodes.
Parasitic fungi: Paecilomyces lilacinus in an effective egg parasite on many nematodes. The parasitic fungus is particularly effective against Meloidogyne, Heterodera, Rotylenchulus and Tylenchulus. The fungus attacks the eggs as they are deposited in groups as a mass. The parasitic fungus was found to be effective against potato cyst nematode, root-knot nematodes in tomato, brinjal, betel vine and banana and T. semipenetrans in citrus.
Bacteria: Recent studies have shown the influence of introduced microbial antagonist in controlling the plant parasitic nematodes. Seed treatment with Pseudomonas fluroscens has been found to reduce the cyst nematode, H. cajani in cowpea. The rhizobacteria viz., Bacillus cereus, Burkholderia cepacia and P. fluroscens were found to be effective against M. incognita in tomato and banana.
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LECTURE NO. : - 13
CHEMICAL CONTROL
Chemical which kill the nematodes are called as nematicides. Nematicide: Nematicide is defined as a substance or mixture of substances used for killing, repelling, or otherwise preventing the plant parasitic nematodes. Kuhn (1881) first tested CS2 to control sugar beet nematode in Germany and he could not get encouraging results. Bessey (1911) test CS2 for the control of root-knot nematodes later formaldehyde, cynide, quicklime. Mathews (1919) chloropicrin (test gas) against plant parasitic nematode in England. In 1944, scientists from California and Florida states of USA reported the efficacy of EDB, DD paved way for chemical control. Classification of Chemicals/ pesticides: The pesticides or chemicals can be classified on their mode of entry, mode of action and also by their chemical nature.
I) Classification based on mode of entry: 1) Stomach poison: The chemicals are applied on foliage and other parts of plant when ingested by the nematode, it act on digestive system and cause death. E.g. Lead Arsenate and Phosphomidon. 2) Contact poison: The toxicant which brings death of the pest species by means of contact and are directly absorb by the cuticle. E.g. Methyl Parathion. 3) Fumigant: The toxicant in its gaseous state penetrates the organism and kill them. CS2, DD and EDB are example for fumigants.
II) Classification based on mode of action: 1) Physical poison: The toxicant which brings death of organism by exerting a physical effect is known as physical poison. The heavy oils like tar oil leads to asphyxiation and cause death. 2) Protoplasmic poison: A toxicant responsible for precipitation of protein, especially destruction of cellular protoplasm of intestine epithelium. E.g. Formaldehyde, Ethylene oxide, Nitro phenols etc. 3) Respiratory poison: A chemicals which blocks the cellular respiration or inactivate cellular respiratory enzymes are respiratory poisons. E.g. H2S, DD and EDB. 4) Nerve poison: These chemicals are anti acetylcholinestrase activity which lead to constant excitation of nerves in the target organism. Due to this, the organism faces convulsions, tremors, muscle paralysis and lead to death. E.g. diazinon & aldicarb.
III) Classification based on chemical nature: 1) Synthetic inorganic compounds: These compounds are systemic inorganic salts which acts as stomach poison and kill the target organism. E.g. Calcium arsenate. 2) Synthetic organic compounds: These group are further classified as i) Halogenated hydrocarbon: e.g. Chloropicrin, methyl bromide, DD, EDB and DBCP etc.
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IV) Natural products: Nicotine, Pyrethrin, Neem cakes. α terthinyl in Marigold, Catechol in Ergrostris, Mustard, Sesame, Bitter cucumber.
Important Nematicides: 1) Ethylene dibromide (EDB): 1,2-Dibromomethane, colourless liquid, gas in non- inflammable, 83% liquid formulation containing 1.2 kg a.i/lit and 35% granules. Use: It is injected/ dibbed into soil @ 60-120 liter or 200 kg ai/ha Toxic- Cyst nematode/fungi. Crop like onion, garlic and other bulb should not be planted after soil treatment with EDB. Trade Name: Bromofume and Dowfume.
2) Dibromochloropropane (DBCP): 1,2- Dibromo-3-Chloropropane, straw coloured liquid BP 1950C, 1 liter of weighing 1.7 kg. Use: Soil treatment before planting, at the time of planting, post-plant treatment, effective when soil temperature is above 200C, sprinkled or mixed with irrigation water. Recommended dose: 10-60 lit/ha. Trade Name: Nemagone, Fumazone.
3) DD mixture: Trade name of the mixture of compound, cis and trans isomers of 1,3-Dichloropropane 30-35% + 1,2-dichloropropane other are few chlorinated 5%, black liquids of 100% formulation, 1 liter of weighing 1 kg technical, inject up to the depth of 15-20 cm at 25 X 30 cm spacing. Use: 225-280 lit/ha. Trade Name: Dibromomethane, Dorlone.
4) Methyl bromide or Bromomethane: Boil at 4.50C gas is heavy 1.5 time than air, insecticidal properties were described by Le Goupil in 1932. Store grain pest it is used 24-32 g/m3 exposure period 48 hrs. Termite/wood beetle @ 32-64 g/m3, fumigation of live plant @ 16-32 g/m3. Application of nematode/ insect @ 4-7 ml/ft2. It also kills the rodents, insects, fungi and weeds in the soil, highly dangerous to warm blooded animals.
5) Chloropicrin or Trichloroditromethane: It is the tear gas, non-inflamable, good penetrating effect. Recommended dose: 16-48 g/m3. It is in control of nematode/ insect in soil. Trade Name: Acquinite and Pic fume.
6) Fensulfothion: It is systemic nematicides, effective against golden nematode in Nilgiri hills. Trade Name: Dasanit, Terracur.
7) Fenamiphos: Systemic nematicide, effective on root-knot nematode and cyst nematodes, 1-5 % granules. Trade Name: Nemacur 40 EC.
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8) Ethoprop: Systemic, effective against juvenile nematode. Trade Name: Mocap.
9) Phorate: Trade name Thimet 10% granules, fumigant action.
10) Metham sodium: Sodium N-methyldithiopcarbamate, Trade Name: Vapam, Sistan, Vitafume and Unifume, Recommended dose 100-200 ml/m2 injected in to soil.
11) Aldicarb: 2-methyl-2 (methylthio) Trade name is Temik, the sulphur atom in the molecule is oxidized to sulfoxide and then to sulfone, it is a systemic, 10% granule, 30-35 days remain residual in plant.
12) Carbofuran: Trade name Furdan, it is systemic insecticide cum nematicide. It is formulated as 3% granule residual effect 30-60 days, got phototonic effect, acropetal action applied @ 1-2 kg ai/ha.
13) Methomyl: It is effective against insects, mites and nematodes, Trade name is Lannate
14) Oxamyl: (Carbomate) 40% EC systemic, effective against foliar nematode, Trade name Vydate.
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INTEGRATED NEMATODE MANAGEMENT STRATEGIES
For Nursery (Transplanted crops):- Keep nursery area fallow (2-3 months) Deep summer ploughing (2-3 ) April-May Grow non-host or antagonistic crops Soil solarization- 100 gauge LLDPE for 20 days Follow rabbing at 7 kg(husk)/m3 Use resistant varieties Green manuring with sunhemp Use bioagents like P. lilacinus, T. viride,T. plus, P. fluorescens at 10 to 20 g/m2 Use effective nematicides like carbofuran 3 G or phorate 10 G at 1 to 2 kg a.i. /ha.
For Field Crops:- Keep the field fallow (2-3 months) Deep summer ploughing (2-3) April-May Flooding (2-3 months) Crop rotation Field sanitation Healthy planting material Resistant varieties Green manuring with sunhemp Grow trap crop, non-host or antagonistic crops Inter or mixed crops with marigold Use FYM or compost at 20-25 t/ha Use non-edible oil cakes at 1 to 2 t/ha Use bioagents like P. lilacinus, P. fluoreascens, T. plus, T. viride at 5 kg/ha Seed treatment with carbosulfan 25 DS at 3 % w/w Seedling root dip with carbolsulfan 25 EC at 0.05 % for 4 to 6 hours. Seed soaking with carbonsulfan 25 EC at 0.05 % for 12 hours. Soil application of carbolfuran 3G, phorate 10 G at 2 to 4 kg a.i./ha.
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LECTURE NO. : - 14
ENTOMOPHILIC NEMATODES
Nematode associate with insects are referred as entomophilic, entomogenus and entomophagus nematodes. They belong to the super families Tylenchoidea, Rhabditoidea, Oxyuroidea and Mermithoidea of phylum nematoda.
Nature of parasitism: Entomophilic nematodes are a group of parasites that cause debilitation, sterility or death of insect. They are vary greatly in size, shape having insects as intermediate are as definite hosts. The earliest nematode parasite of insect is Mermis nigrescens from grasshopper locusts and other insect. The insect become infested with M. nigrescens by feeding on vegetation where the dark brown nematode eggs are deposited. The host is vulnerable throughout life cycle. Developing female nematode remains longer in the host. It affects morphology and physiology of insect. The gut and oviduct become compress and distorted. Cuticle becomes discolored and softened. Inhibition of molting reduced excretion, sterilization of female host. It is always fatal to host.
Entomophagic nematodes: A symbiotic bacteria Xenorhabdus spp. is associated with Steinernema spp., Photorhabdus spp. with Heterorhabditis. The bacteria are responsible for death of host. It occurs primary/secondary from the bacterium P. luminescens is bioluminescent. The free living J3 larval of nematodes are resistant to desiccation and can survival for several months. They enter through mouth /anus. On entering in to host, they penetrate the wall of alimentary canal and move to body cavity. The host haemolymph taken by the nematodes and accumulates in anterior part of their intestine. The bacteria in pouch multiply and release through the anus of nematode body of the host insect. In the host, the bacteria multiply and cause septicemia. The nematodes develop on bacteria and in decomposed tissues of host insect. The host dies in about 48 hrs. after infection. High effective against lepidopterans Spodoptera litura, Helicoverpa armigera, Papilio demoleus and Agrotis segtum.
Entomophilic Nematode: 1. Neotylenchus -Scirpophaga novella 2. Panagrolaimus -Chlo zonellus 3. Rhabditis -Chilo zonellus 4. Mermithids -Cirphis 5. Mermis -Amsacta moorei 6. Agamermis -Trypozyza incertulas 7. Hexamermis - Spodoptera litura, Scirpophaga novella, Chilo infuscatellus.
ENTOMOPATHOGENIC NEMATODES (EPN) Entomopathogenic nematodes (EPN) are beneficial nematodes parasitizing crop insects, particularly lepidopterans and coleopterans and are effectively used as biopesticidesagainst a vide variety of insect pests. The impressive attributes of EPN have stimulated strong commercial interest in nematodes as biological insecticides and are percived as viable alternative to chemicals in IPM programme.
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Complied by Prof. T. B. Ugale & Prof. A. S. Mochi (K. K. Wagh College of Agriculture, Nashik)
Difference between EPN & PPN: Entomopathogenic nematode and plant paracitic nematodes differ both in structure and behaviour from each other. A comparative table gives the most significant differences between the two groups. Sr. Entomopathogenic Nematode Plant Parasitic Namatode (PPN) No (EPN) 1 Parasitic on insect pests and pass Parasitise mainly root system of plants one of the stage of their life cycle in and pass one of the stage of their life insect pests. They never parasitise or cycle in/ on the root tissues of plant as damage to plant endoparasitic/ ectoparasitic nematode. 2 Beneficial to Agricultural crops by Harmful to Agricultural crops damage attacking insects pests by killing and alter physiology of crop plants, them quickely. produce abnormalities, knots, lesion on root system, introduced fungal pathogen inside roots and aggravate wilt and root-rot diseases. 3 Increase crop yield by killing crop Inflicting 15% yield loss on an average pests as a biological control agent in Agricultural crops globally as a parasite. 4 Size 0.3-1.5 mm (very small) Size upto 4 mm (small to medium) 5 Absence of stylet Presence of stylet 6 EPN feed on bacteria and PPN feed on the plant part mainly root decomposing host insect. to get their nourishment. 7 Life cycle completes within a week. Life cycle completes in 20-30 days. EPN have many attributes which make them a good and promising biocontrol agent. They often behave like insecticide or other plant protection chemicals. They can be easily incorporated as a component of IPM programme.
Some typical characters of EPN: Ablity to search (chemoreceptors) the target insect in soil, plant surface. Quick kill of the target insect through release of bacteria. Broad host range: Coleoptera, Lepidoptera, Diptera, Orthoptera, Homoptera etc. Can be recovered from soil and mass multiplied with in a short period. Easily cultured on artificial diet or living hosts. Can be stored for longer perriod in soil, cadaver, in partially desiccated state and recieved when needed. They are compatible with many pesticide can be formulated as dust, sprays, capsules, grannules etc.and applied spraying EPN suspention or through irrigation system. These are safe to vertebrates, plants and non-target organisms. They are environmentaly safe and self perpetuating in nature. No registration required. EPN falling three genera namely Steinernema, Neosteirnema and Heterorhabditis.
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Complied by Prof. T. B. Ugale & Prof. A. S. Mochi (K. K. Wagh College of Agriculture, Nashik)
Dignostic characters between Steinernema and Heterorhabditis.
Steinernema Heterorhabditis. Symbiotic bacteria Species associated-Xenorhabdus. Species associated-Photorhabdus. Bacteria location- within specialized Bacterial intestinal vesicle. Adults Excretory pore located anterior to nerve Excretory pore located posterior to nerve ring. Spicule ventraly arcute. Bursa ring. Spicule nearly straight. Bursa absent. Genital papillar – 10-11 pairs. present. Genital papillae-9 pairs. Infective juveniles Excretory pore anterior to nerve ring Excretory pore posterior to nerve ring Luminescence – No Luminescence – Yes Colour of dead larva- Black Colour of dead larva- Red, pink.
Identification of Entomopathogenic Nematode: Adult: Obligate parasite, adult stage founding the haemolymph of infected insect, adults are amphidelphic, stylet absent, amphid aperture located on lateral lips. Female: Amphidelphic, didelphic with reflexed ovaries, vulva media, functional only during mating, mature females ovoviviparous, developing larvae consume the entire body content and eventually filling the females, females cuticle degenrates and larvae are released. Male: Testes single, reflexed, spicule paired, separate with or without vallum, gubernaculum present, genital papillae nipple shaped. Infective juvenile: Third stage is dauer stage or infective in nature and found in soil. Stoma and anus closed, Excretory pore on nerve ring mouthregin armed. Tail elongate. Capable of killing wide range of insects due to septicemia caused by symbiotic bacteria. Nematode biology: Juvenile of EPN pass through four stages. The first two stage may be developed on food material. The parasitic cycle of nematodes is initiated by the third state IJS (infective juveniles). These non-feeding juveniles locate and invade suitable host insects through natural body openings (i.e. anus, mouth and spiracles). Once inside the host, nematodes invade the haemocoel and release the symbiotic bacteria that are held in nematode intestine. The bacteria cause a septicemia, killing the host with in 24-72 hrs. The IJS feed on the rapidly multiplying bacteria and disintegrated host tissues. About 2-3 generations of the nematodes are completed within the host cadaver. When food reserves are deplected the reproduction ceases and the offspring develop into resistant IJS that disperse from the dead host and are able to survive in the environment and to seek out new hosts. Soon after death, the cadevers turn flaccid and starts changing coloure. In case of wax moth larvae and depending upone nematodes species, Steinernematid killed insects turn to various shades of brown, orchre, whereas Heterorhabditid killd insect turn red, brick red, purple orange, yellow and some times green. The colour of the cadever is attributed to the associated bacterium, especially photorhabdus that have pigmens. If the cuticle is transparent, nematodes are visible incide the cadever.
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Complied by Prof. T. B. Ugale & Prof. A. S. Mochi (K. K. Wagh College of Agriculture, Nashik)
LECTURE NO. : - 15 MODE OF ACTION
Ovicidal Inhibition of egg hatching Lack of penetrability of larvae Mortality in larvae Toxic to Nematodes/ Nematicidal Nematostatic Inability to complete life cycle Inhibition of egg laying capacity of females Directly toxic Disturbing pH Creation of unfavorable condition for nematode development & multiplication
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Complied by Prof. T. B. Ugale & Prof. A. S. Mochi (K. K. Wagh College of Agriculture, Nashik)
LECTURE NO. : - 16 MASS PRODUCTION TECHNIQUES FOR EPN
The EPN are multiplied either on a suitable host (in vivo) on a semi-synthetic diet (in vitro). Both the techniques of mass production of EPN have their own advantages and limitations In vivo production EPN are baited out and multiplied on host insects. Three host insects viz’; i) Galleria mellonella ii) Corcyra cephalonica iii) Helicoverpa armigera.
The method of preparation of diet and mass multiplication of host insect. i. Galleria mellonella: Culture of G. mellonella can be done and easily maintained in laboratory. The ingredients for the artificial diet of G. mellonella are as follows. Part-A Part –B Corn flour 200 g Glycerin 150 ml Wheat bran 100 g Honey 150 ml Skimmed milk power 100 g Yeast tablets 50 g Yeast tablets are grinded into a fine powder and mixed with corn flour, wheat bran and milk powder. Glycerin and honey are mixed separately. Finally, part A and B are mixed thoroughly and homogenous mixture is prepared. The content of artificial diet is distributed in two plastic containers (5 lit. capacity). About 1000 first or second instar G. mellonella larvae are released in each container and incubated at 350C. The larvae will be ready for use within three weeks. If the temperature is < 350C development of larvae will be slow. ii. Corcyra cephalonica: 1. Broken sorghum or wheat grain 1 kg 2. Maize meal 1.0 kg 3. Rice broken 500 gm. 4. Streptomycin 0.5 gm. 5. Yeast powder 1 gm. About 1.00 CC Corcyra eggs aremixed with this and perforated lid is secured and kept for about a month. The fully grown larvae are utilized for multiplication of EPN.
iii. Helicoverpa armigera: The ingredients for artificial diet of H. armigera are Chickpea flour 84 g Casein protein rich purified 10 g Agar agar 11 g Cholesterol/vegetable oil 0.1 ml Yeast extract powder 11 g Methyl P’-4 hydroxybenzoate 2 g Sorbic acid 1 g Streptomycin sulphate 0.01 g Ascorbic acid 5 g Distilled water 600 ml
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Complied by Prof. T. B. Ugale & Prof. A. S. Mochi (K. K. Wagh College of Agriculture, Nashik)
Yeast extract, sorbic acid casein, cholesterol methyl P-4 hydroxybenzoate and Streptomycin sulphate are mixed well in a grinder with 400 ml water. In another container, agar agar is added in200 ml distilled water heated. All the ingredients are thoroughly mixed in grinder. Thereafter, the ingredient is poured in petri plates/vial and kept at room temp. to cool down. Now, diet is ready for use H. armigera larvae are collected from field of chickpea or pigeon pea on maintained on artificial diet under laboratory condition.
Production of EPN in vivo Production of EPN on insect is generally done by using while trap method. Insect are inoculated with EPN on a petridish lined with filter paper. After 2-5 days, infected insects are transferred to the white trap. This method consists of a dish on which the cadavers rest on inverted watch glass, surrounded by water the central dish containing the cadavers provides a moist surroundings for the EPN emergence from cadaver. New progeny of infective juveniles that emerge from cadaver migrate to the surrounding water where they are trapped and subsequently harvested. This method has the advantage that the IJS migrate away from host cadaver on emergence and continue to do so until the body contents of the host are consumed.
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Complied by Prof. T. B. Ugale & Prof. A. S. Mochi (K. K. Wagh College of Agriculture, Nashik)
Production of EPN in vitro For in vitro production of EPN, various media have been reported. The following media have been proposed and their ingredients are as follows: Wout’s medium: Nutrient broth (0.88 g), soybean flour (14.40 g), groundnut oil (10.40 g) and distilled water (60 ml). Modified Wout’s medium: Nutrient broth (0.50 g), yeast extract (0.20 g), soybean flour (16.00 g), groundnut oil (12.00 g) and distilled water (30 ml). Wheat flour medium: Wheat flour (15 g), Kabuli gram flour (5 g), beef extract (5 g), yeast extract (6 g), agar 1% (1 g), coconut oil (6 g) and distilled water (60 ml). Modified wheat flour medium: Wheat flour (15 g), Kabuli gram flour (5 g), beef extract (5 g), yeast extract (1 g), agar 1% (1 g), groundnut oil (10 g) and distilled water (60 ml). Egg yolk media I: SDEY (7 g), yeast extract (2 g), NaCl (0.8 g), oil (15 g) and distilled water (60 ml). Egg yolk media II: SDEY (10 g), yeast extract (5 g), NaCl (0.8 g), oil (12 g) and distilled water (60 ml). Egg yolk media modified: SDEY (7 g), soybean flour (20 g), yeast extract (2 g), NaCl (0.8 g), oil (15 g) and distilled water (60 ml). Dog biscuit medium: Dog biscuit (15 g), yeast extract (1 g), peptone (3 g), agar (2 g), oil (10 g) and distilled water (60 ml). Modified dog biscuit medium: Dog biscuit (20 g), yeast extract (1 g), peptone (3 g), beef extract (5 g), oil (7 g) and distilled water (100 ml).
Mix the ingredients and coat on to polyether polyurethane from cut into small cubic pieces till the latter soaked in the media (1.5 g of foam chips, 8-9 g medium, w/w). The flask filled with foam-media impregnated water and autoclaved for 20 min at 1210C and allowed to cool. Fresh infective juveniles extracted from insect will be used each time to avoid the prior inoculation of bacteria in the flasks. The nematodes should be inoculated aseptically in to the flask @ 1000 Ijs/flask. Incubate the sealed flask at 280C for 25 days. The colonies of EPN will start appearing on the wall of flask after two weeks post inocolation. After 25 days of inoculation infective juveniles will be harvested. Piled up the foam chips on 100 mesh sieve. Place the sieve in a pan of distilled water overnight. The nematodes seddiments pass through a 250 mesh sieve in a pan of water. About 95% infective juveniles migrate into the water within 2 hour and sterilized with 0.1% Hymine solution, wash thrice with sterile distilled water and collect and store at room temperature. After concentrating nematode suspension with the help of micro filtration assembly. EPN will be kept till further use.
(Techniques for mass production of Entomopathogenic Nematodes See in practical mannual)
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INSECT ECOLOGY The term ecology was coined by a German biologist Ernst Haeckel (1869). The term ecology is derived from the Greek word “oikos” means “house or place to live” & “logous” means “the science of” or “the study of”. Thus literally ecology is the study of earth’s household comprising of the plants, animals, microorganisms and people that live together as interdependent components.
Terminology Related to Ecology 1) Ecology: - It is the science which deals with the study of relationship of organisms with their environment including both biotic & abiotic factors. 2) Insect Ecology: - The science which deals with the study of relationship of insects to their environment. 3) Auto ecology: - Study of an individual organism, its behavior and influence of environment on its life cycle. 4) Synecology: - Study of groups of organism which are found as unite called community ecology. 5) Habitat ecology: - Study of habitat and its effects on the organisms. 6) Ethology: - Study of behavior of organisms under natural condition. 7) Habitat: - It is the place where the organism lives. 8) Population: - denotes groups of individuals of any kind of organism. 9) Community: - in the ecological sense includes all the populations of a given area. 10) Ecosystem: - A self-containing system they are composed of living organisms and the nonliving environment where continuous exchange of matter and energy takes place. 11) Biome: - The grouping of communities that have similar structure composed of ecosystem of similar vegetation type. 12) Biota: - Fauna and flora of a particular habitat are together called biota. 13) Biosphere: - It is the largest ecosystem which includes all living organism on earth interacting with physical environment. 14) Ectone: - Some communities which are considered to be transitional between two biomes called Ectone. 15) Inquilines: - An animal lives in the habitat of another one with sharing its food. 16) Phoresy: - A commensalistic relationship among the organisms in which one kind of organism attacks to another thereby gains mode of transportation. 17) Bioaccumulation: -It is the process of accumulation of substances, such as pesticides, or other chemicals in an organism when absorbs at a rate faster than that at which the substance is lost by catabolism and excretion. E.g. Use of DDT causes bioaccumulation. 18) Biomagnification (Bioamplification/Biological magnification): - also known as, is the increasing concentration of a substance, such as a toxic chemical, in the tissues of tolerant organisms at successively higher levels in a food chain.
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ENVIRONMENT: ITS COMPONENTS The term environment entomologically means “Surroundings”. Environment is a complex of living and non-living factors which surrounds on organisms. Environment: - An environment is anything which surrounding to individuals that may influence its change to survive and multiply. Components (Factors) of environment: -Following components of environment affect or influencing on insect population. Abiotic Factors: Biotic factors: (Physical/non-living /Density independent factor) (Living /Density dependent factor) A) Climatic factor A) Food (Nutritional factor) i) Temperature B) Competition (Interspecific & Intraspecific Competition) ii) Rainfall C) Natural enemies (Predators, Parasite & Pathogen) iii) Humidity (Moisture) iv) Air current (Wind) v) Light vi) Atmospheric pressure B) Topographic factor i) Mountains ii) Sea, Ocean, River iii) Soil
Abiotic Factors (Density independent factors): -
Temperature- Insects are the cold blooded animals; they do not have mechanism to regulate body temperature called poikilothermic. Insects survive at specific optimum temperature - Upper lethal limit is s 40- 50oC (even up to 60oC survival in some stored product insects) & Lower lethal limit - Below freezing point e.g. snow fleas. At low temperature (winter) insect takes more days to complete a stage (larval or pupal stage) Larva, pupa commonly undergoes hibernation in winter. At high temperature (summer) it takes less than to complete a stage. Eggs undergo aestivation in summer. Temperature effects on fecundity, migration & rate of development of insects. E.g. i) Grasshopper lays 20-30 times more eggs at 32oC compared to 22oC,Oviposition of bed bug inhibited at 8-10oC, iii) Thrips give few eggs at 8°c& more at 20-30°c, iv) Larval period of sugarcane internode borer is very short in summer & prolonged in winter & v) Swarm migration of locust occurs at 17-20oC.
Rainfall- Heavy rainfall has adverse effect on small insects like aphids, Jassids, thrips, white fly, mealy bugs, diamond back moth (DBM) and scale insects etc. which are washed out from plants & killed in flooded soil. Rainfall also effect on the abundance of insects. Rainfall is essential for adult emergence of cutworms and Red hairy caterpillar.
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Humidity/ (Moisture) - It is essential for physiological activities like metabolic reactions and transportation of salts in insects. Insect get die when water content increases or decreases termed as lethal wetness or lethal dryness. Moisture scarcity leads to dehydration and death of insects. High humidity causes development / Encourages of disease causing pathogens on insects (fungi). e. g. White halo fungus Verticilium lecanii on coffee green scale requires high RH for multiplication and spread, Termites prefer high humidity 90-95% RH. Humidity also effect on fecundity & normal development of insects. E.g. Locust does not lay eggs if there is no sufficient moisture. It mature quicker & give more eggs at 70% relative humidity, Low RH in rainfed groundnut crop induces leaf mines incidence. Air current (Wind) - The disposal of insects to great extent depends upon wind. It interferes with feeding, mating & oviposition of insects. Many insects fly with the air current & get transfer from one place to other. Many of them die by falling in rivers or sea. Many insects are known to spread in new countries through air currents. Large number of aphids has been found after a strong wind & many of them are destroyed by falling in the sea & rivers etc. Thus air current also play an important role in natural control of insects. Light- Light plays an important role in growth, development & survival because it is prime source of energy in all organisms. Light control locomotive activities of insects by direct action this phenomenon is called as Phytokinesis. The movement of animal in response to light called phototaxis. The response of organism towards the length of day light called as Photoperiodism. Photo period influences induction of diapause (a resting stage) in most of the insects. E. g. Short day species- mulberry silk moth & Long Day Species-Pink bollworm some insects are active in night (Nocturnal); some are active during the day (diurnal) & some active during dawn and dusk (Crepuscular). In many insects oviposition is stimulated by exposure to light or darkness. E.g. Fruit flies lays eggs in light, Lepidopterans like cotton bollworm, Red hairy caterpillar (RHC) oviposit in dark. Atmospheric pressure- The insects are more affected in low atmospheric pressure than in high atmospheric pressure. The phototrophic insects are more active during periods of high atmospheric pressure. The activities of some insects are directly influenced by pressure. E.g. due to the low atmospheric pressure a chances of rain increased resulting the emergence of ants. Topographic factors- Major topographic factors like mountain, rivers, sea are act as physical barriers to the spread of insects. Lake & ponds affect the nature of insects of that region. Water current -Larva of mosquitoes & beetles are able to live only in standing water & running water is preferred by Dragonfly and Caddis flies. Soil type - Wire worm, multiplies in heavy clay soil with poor drainage whereas termites, white grubs & cut worm prefer light, loamy soil. 4
Biotic Factors (Density dependent factors): -
Food (Nutritional factor)- Insects are heterotrophic hence they cannot synthesize their own food they depend on plants for food. The quantity and quality of food/nutrition plays important role in survival, longevity, distribution, reproduction and speed of development. Quantity of food - Short supply of food causes intraspecific and interspecific competition and Quantity of food - This depends on nutritional availability of plants. Crop varieties/species differ in nutritional status which affects insects.
Competition- Insect species are likely to be competing with one another or with members of another species for limited resources like food, mates, and suitable site for oviposition or pupation. Such competition operates whenever the population is increasing and the resources are limited. They are divided into; a) Intraspecific competition: When members of population of the same species compete for resources. Examples are as follows; i) Cannibalism in American bollworm larvae, ii) Cannibalism in later stage grubs of Chrysopid, iii) Crowding in aphids result in alate (winged) form for migration, iv)) Reduction in fecundity (egg laying) in rice weevil during overcrowding. v) Crowding in honeybees leads to swarming. b) Interspecific competition: This is the competition occurring between members of two or more species. Two or more competing species with identical requirements cannot coexist in a same place for a long time. The elimination of one species by another as a result of interspecific competition. It gives by Russian scientist G. F. Gause called competitive exclusion principle or Gause’s hypothesis/principle. It occurs by Cannibalism: - It is the phenomenon where the insects feed on the individuals of the same species when crowding is occurring. Colonization: - Grouping of free living individuals to form colonies to have better protection from natural enemies or environmental conditions for improved utilization of food. Aggregation: - Tendency of congregating in large numbers than normal distribution for mating, food etc. E.g. i) Accidental introduction of oriental fruit fly into Hawaii eliminated by Mediterranean fruit fly & ii) Tichogramma & Chrysoperla compete for Helicoverpa eggs in cotton.
Natural enemies: - Every insect has a number of natural enemies in the nature viz; parasitic insects, predatory insects, mites, spider, birds, mammals, reptiles, fishes & diseases causing fungi, bacteria & viruses. The association of parasite and host known as parasitism. They keep the insect population in check and thus natural balance within limits is almost always maintained. 5
Predators: Predators are free living organisms that feed on living insects & consume more than one individual during their lifespan. Major insect predators are as follows; o Lady Bird beetle (Coccinellids) - Feed on aphids & leaf hoppers. o Green lace wing (Chrysoperla spp.) - Feed on aphids & other sucking pests. o Mantid, Dragon fly & Syrphid fly -Feed on different insects.
Parasitoid: An insect parasite of an arthropod that is parasitic in its immature stage killing the host in the process of development and adults are free living. Major insect parasitoids are as follows; o Trichogramma spp. - Feed on Sugarcane borers & Cotton bollworms. o Apanteles flavips-Feed on lepidopteran larvae. o Epiricania meloneuca- Feed on sugarcane pyrilla. o Capidosoma koeheleri & Chilonus blackberni- Feed on potato tuber moth
Pathogens: Disease causing microorganisms called as pathogens. Certain fungi bacteria & viruses cause disease in many insects & reduce their population in nature. The important microorganisms which cause disease in insects are as follows; o Fungi - E.g. Verticillium lecanii (White halo fungus) cause disease in mealybugs & aphids, Beaveria Bassiana (White muscardine fungus) cause disease in lepidopteran larvae & Metarhizium anisopliae (Green muscardine fungus) in coconut rhinoceros beetle. o Bacteria - E.g. Bacillus thuringiensis effective against lepidopteran larvae & Bacillus papillae attacking on beetles. o Virus - E.g. HaNPV (Helicoverpa armigera nuclear polyhedrosis viruses) against American bollworm. &SlNPV - (Spodoptera litura nuclear polyhedrosis viruses) against tobacco leaf eating caterpillar. o Other Natural Enemies: Frog, Toad, reptiles, birds, rats, bears, snakes & lizard.
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ENVIRONMENTAL RESISTANCE & PEST OUTBREAKS Agroecosystem - Any ecosystem largely created and maintained to satisfy a human want or need. It is not a natural ecosystem but is man-made. Agroecosystem is the basic unit of pest management. It is a branch of applied ecology. A typical agroecosystem is composed of; More or less uniform crop-plant population, Weed communities, Animal communities (including insects), Macrobiotic communities and the physical environment the react with.
Balance of Nature - “The maintenance of more or less fluctuating population density of a given organism over a period of time with in certain definable upper and lower limits by action of abiotic and biotic factors”. Or a tendency of population density of all species in a same area to maintain a constant number of individuals in the physical environment. The concept of Balance of Nature was given by Smith in1935. In unmanaged ecosystems, a state of balance exists or will be reached, that is species interact with each other and with their physical environment in such a way that on average, individuals are able only to replace themselves. Each species in the community achieves a certain status that becomes fixed for a period of time and is resistant to change which is termed as the balance of nature. When man begins to manage creating new ecosystem (agroecosystem) where natural ecosystem existed previously, the balance is altered. The exceptionally strong forces react in opposition to our imposed change toward a return to the original system (e.g. outbreak of a pest is one of the forces). So, insect pests are not ecological aberrations. Their activities counter wants and needs of human populations.
Biotic potential - It is the innate ability of the population to reproduce and survive. It depends on the inherited properties of the insect i.e., reproduction and survival. Potential natality is the reproductive rate of the individual’s in an optimal environment. Survival rate depends on the feeding habits and protection to young ones. Generally insects with high reproductive rate tend to have low survival rate and vice versa. Insect pests with high reproductive rate and low survival rate are called r strategists named after the statistical parameter r, the symbol for growth rate coefficient. E.g. Aphids. Insect pests with low reproductive rate and high survival rate are called K strategists. (K letter denotes flattened portion of growth curve) e.g. Codling moth of apple. Birth rate or natality is measured as the total number of eggs laid per female per unit time. Factors determining birth rate are fecundity, fertility and sex ratio. Death rate or mortality denotes the number of insects dying over a period. 7
Environmental resistance - It is the physical and biological restraints that prevent a species from realizing its Biotic potential. K’ Mortality factor - it is that factor existing in natures that are responsible for mortality of the insects. Population dynamics: -Insect populations grow in two contrasting ways; J- shaped growth form and S- Shaped or sigmoid growth form In the J - shaped growth form, the population density increases in exponential or geometric fashion. Populations with this kind of growth form are unstable. Their reproductive rate is high and survival rate is less and so they are r strategists. Factors other than density regulate the population. (e.g.; Aphids) In the S-shaped growth pattern the rate of increase of density decreases as the population increases. Their reproductive rate is less and survival rate is more. So they are K strategists. This pattern has more stability since the population regulates itself. (E.g. Hymenopterans)
Life table: Life tables are tabular statements showing the number of insects dying over a period of time and accounting for their deaths. Life table is a numerical aid used in the study of insect population to record in a systematic fashion. There are two types of life table; o Age specific (Horizontal) life table - It is based on the observations made on single generation in different region. o Time specific (Vertical) life table - It is based on the observations made on overlapping/multiple generation. Uses of life table: o Number of generations per year of an insect can be known. o Age of different life stages can be known. o Key mortality factor & critical stages affected can be known. o Population models can be developed from life table. o Pest surveillance, pest forecasting & prediction of pest can be possible. o It is possible to regulate beneficial processes like parasitism, predation, inter& intraspecific competitions etc.
General causes of pests outbreaks in agro-ecosystem Pest outbreaks: - The phenomenon of sudden increases in pest population due to the effect of different biotic & abiotic factors. The following are some human interventions - Reason for outbreak Bringing forest area under cultivation or destruction of forest. Destruction of natural enemies of pests. Intensive and Extensive cultivation. Introduction of new varieties and crops. Improved agronomic practices. Introduction of new pest in new area or environment. Accidental introduction of pests from foreign countries (through air/sea ports) Large scale storage of food grains Lack of adopting IPM strategies. Resurgence of sucking pests. 8
. Bringing forest area under cultivation or destruction of forest- The insects feeding on the forest trees & plants in the forest are driven to neighboring areas where they may infest the cultivated crops and become new pests. . Destruction of natural enemies of pests-Due to excess use of insecticides, natural enemies is killed. This affects the natural control mechanism and pest outbreak occurs, e.g. Synthetic pyrethroids insecticides kill natural enemies. . Intensive and Extensive cultivation-Monoculture (Intensive) leads to multiplication of pests. Extensive cultivation of susceptible variety in large area - No competition for food multiplication increases e.g. Stem borers in rice and sugarcane. . Introduction of new varieties (Strain) and crops-New plant may serve as new host for some of the insect species. Mostly improved strains of crop plants are susceptible to pests whereas character near to their wild parents is resistant to pest attack. Varieties with favorable physiological and morphological factors cause multiplication of insects. E.g. Succulent, dwarf rice varieties favors to leaf folder, Cambodia cotton favors stem weevil and spotted bollworm & Hybrid sorghum (CSH 1, HB1) favors shoot flies and gall midges. . Improved agronomic practices-Application of more nitrogenous fertilizers leads to crop growth which increase stem borer incidence in rice & sucking pests in cotton. Closer planting in rice increase incidence of brown plant hoppers & leaf folder. . Introduction of new pest in new environment-Pest multiplies due to absence of natural enemies in new area. E.g. Apple wooly aphid multiplied fast due to absence of Aphelinus mali (Parasite) in Nilgiri hills. . Accidental introduction of pests from foreign countries-Diamondback moth on cruciferous crops, Potato tuber moth on potato, Cottony cushion scale on wattle tree, Wooly aphid on apple, Psyllid on subabul & Spiralling whitefly on most of horticultural crops. . Large scale storage of food grains-Serve as reservoir for stored grain pests & Rats found in underground drainage. . Resurgence of sucking pests- Tremendous increase in pest population brought about by insecticides despite good initial reduction in pest population at the time of treatment called resurgence. Deltamethrin, Quinalphos & Phorate cause resurgence of BPH in rice, Synthetic pyrethroids cause resurgence of Whitefly in cotton & Carbofuran cause resurgence of Leaf folder in rice.
PEST SURVEILLANCE AND PEST FORECASTING Pest Monitoring - It is the estimation of changes in insect distribution and abundance, information about insects & life history, influence of biotic &abiotic factors on pest population. Pest Surveillance - It refers to the constant watch on the population dynamics of pests, its incidence and damage on each crop at fixed intervals to forewarn the farmers to take up timely crop protection measures. There are three basic components of pest surveillance; 1) Determination of the level of incidence of the pest species, 2) Determination of the loss caused by the incidence & 3) Determination of the economic benefits, the control will provide.
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Objective of pest surveillance: - To know the existing and new species of pests. To assess the pest population and damage at different growth stage of crop. To study the different weather parameters on pests. To study changing pest status (Major & minor). To assess natural enemies and their influence on pests. To study effect of new cropping pattern and varieties on pest. Pest forecasting - Forecasting of pest incidence or outbreak based on information obtained from pest surveillance. Uses of pest forecasting - Predicting pest outbreak which needs control measure. To know the suitable stage at which control measure gives maximum protection. Types of pest forecasting - 1) Short term forecasting- one or two crop seasons. 2) Long term forecasting- cover large areas & based on weather conditions. Pest forecasting comprises following three main points: - 1. Quantitative measurement of population of pest on ecological zones. 2. Study of life history of the insect pest. 3. Study of fluctuation in pest population due to natural enemies & other factors. Survey: - Conducted to study the abundance of a pest species. Types of survey - 1) Roving survey 2) Fixed plot survey 1) Roving survey- Assessment of pest population/damage from randomly selected spots representing larger area. Large area surveyed in short period. Provides information on pest level over large area. 2) Fixed plot survey-Assessment of pest population/damage from a fixed plot selected in a field. The data on pest population/damage recorded periodic from sowing till harvest. It may be Qualitative survey - Useful for detection of pests and Quantitative survey - Useful for enumeration of pest. Sampling technique - 1) Absolute - To count all the pests occurring in a plot. 2) Relative - To measure pest in terms of some values which can be compared overtime and space e.g. Light trap catch, Pheromone trap. Methods of sampling - a) In situ count - Visual observation on number of insects on plant canopy (either entire plot or randomly selected plot). b) Knock down - Collecting insects from an area by removing from crop and (Sudden trap) counting (Jarring). c) Netting - Use of sweep net for hoppers, Dragonfly, grasshopper and butterfly. d) Narcotized collection - Quick moving insects anaesthetized and counter. e) Trapping - Light trap - Phototropic insects, Pheromone trap - Species specific, Sticky trap - Sucking insects, Bait trap - Sorghum shoot fly & Fishmeal trap Emergence trap - For soil insects. f) Crop samples - Plant parts removed and pest counted e.g. Bollworm. 10
PESTS AND THEIR CATEGORIES Pest- Derived from French word ‘Peste’ and Latin word ‘Pestis’ meaning plague or contagious disease. Pests include insects, nematodes, mites, snails, slugs, etc. and vertebrates like rats, birds, etc. Depending upon the importance, pests may be agricultural forest, household, medical, aesthetic and veterinary pests. Definition - Pest is any animal, pathogen, insects which cause damage to man, his animals & crops. Or Pest is any animal which is noxious, destructive or troublesome to man or his interests. Economic Pest: - The pest which causes more than five percent economic yield loss.
Categories of pest: - A. According to frequency of occurrence: - Regular pest: Certain pests occur most frequently on crop form close association with particular crops. E. g. Gram pod borer, Thrips on chilies, Aphids on cotton, soot & fruit borer on Brinjal & bhendi & Epilachna beetle on Brinjal. Occasional pest: Certain pests occur rather infrequently on crop & there is no close association with particular crops. E. g. Caseworm on rice, Mango stem borer. Seasonal pest: Occurs during a particular season every year. E. g. Grasshoppers on safflower in kharif, Red hairy caterpillar on groundnut in kharif, White grub Persistent pests: Occurs on the crop throughout the year and is difficult to control. E. g. Chilli thrips, mealy bug on guava. Sporadic pests: Pest which occurs in few isolated localities during some period. E. g. Coconut slug caterpillar, Rice ear head bug.
B. According to intensity of pest or Based on level of infestation: - Epidemic: Sudden outbreak of a pest in a severe form in a region at a particular time. E. g. Brown plant hopper in Tanjore, Red hairy caterpillar in Madurai. Endemic: Occurrence of the pest in a low level, regularly and confined to particular area. E.g. Rice gall midge in Madurai, White grubs on sugarcane in Kolhapur district, Groundnut in Sangali, Rice stem borer in Raigad district.
C. According to losses caused by pest or According To EIL, GEP and DB: - Negligible: If the insect causes less than 5% yield loss. Minor pest: If the insect causes 5-10% yield loss. E.g. Rice hispa, Ash weevils. Major pest: If the insect cause more than 10% yields loss. E.g. Cotton Jassids. Rice stem borer. Key pest: Most severe and damaging pests & GEP lies above EIL always hence, the environment must be changed to bring GEP below EIL. E.g. Cotton bollworm, Diamond back moth. ‘r’ pest: small size insects having strong dispersal & more host finding ability.
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INTEGRATED PEST MANAGEMENT (IPM)
Historical Event: - Michel bacher and Bacon (1952) coined the term “integrated control”. Stern et al. (1959) defined integrated control as “applied pest control which combines and integrates biological and chemical control” The idea of managing pest population was proposed by Geiger and Clark (1961) who called this concept as “protective population management”. Geier (1966) coined the term “pest management”. Council on Environmental Quality (CEQ, 1972) gave the term “Integrated Pest Management” IPM Working Group (IPMWG-1990) was constituted to strengthen implementation of IPM at international level. In 1997. Smith and Adkisson were awarded the World Food Prize for pioneering work on implementation of IPM. NCIPM: National Centre for Integrated Pest Management at Faridabad (New Delhi) (1988). In 1967 a broader definition was adopted by FAO (Food Agricultural Organization, Italy- Rome) Panel of experts as - Definition: - ‘It is the pest management system in context of associated environment and population dynamics of pest species utilize all the suitable techniques and methods in as compatible manner as possible and maintains pest populations at level below those causing economic injury.’
Need for Pest Management - Development of resistance in insects against insecticides e.g. OP and synthetic pyrethroid resistance in Helicoverpa armigera. Outbreak of secondary pest e.g. Whiteflies emerged as major pest when spraying insecticide against H. armigera. Resurgence of target pest e.g. BPH of rice increased when some OP chemicals are applied. When number of application increases, profit decreases. Environmental contamination and reduction in its quality. Killing of non-target animals and natural enemies. Human and animal health hazards.
Objectives of pest management- To reduce pest status below economic injury level. Complete elimination of pest is not the objective. To manage insects by not only killing them but by preventing feeding, multiplication and dispersal. To use ecofriendly methods, which will maintain quality of environment (air, water, wild life and plant life) To make maximum use of natural mortality factors, apply control measures only when needed. To use component in sustainable crop production.
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Principles of Pest Control: Identification/Monitoring insect pests and natural enemies of pest. Insect classification and life history. Understanding the pest population dynamics & Concepts of injury levels. Understanding the agro-ecosystem. Knowledge of introduced pest. Economics of the pest control. Consumer’s pressure. Preventive control. Knowledge of various pest control methods/Integration of pest control tactics. Extension Education.
Advantages/Importance/Significance of IPM: - It minimizes residue & toxic hazards. It helps to minimize the development of pesticide resistance in the pest. It gives scope to biological control & bio-agents. It is easy to adopt. It is cheaper & most efficient way of utilizing chemical insecticides. It is ecologically beneficial to both human & animals. Export of agricultural commodities.
Limitations/Disadvantages of IPM: - Lack of planning in national economic planning. Lack of IPM information to the farmers. Pesticide industries create a situation that chemicals give effective control of pest.
Concept of injury level-Population or damage assessed from the crop compared with ETL and EIL. When pest level crosses ETL, control measure has to be taken to prevent pest from reducing EIL. Concept of injury level was given by Stern et al. 1959.
Economic Injury level (EIL): - The lowest pest population density that will cause economic damage. Also defined as a critical density where the loss caused by the pest equals the cost of control measure. Economic Threshold Level (ETL) or Action threshold: - The pest population density at which control measures should be applied to prevent the economic yield loss of crop. ETL is always less than EIL.
General equilibrium position (GEP):- The average density of a pest population over a long period of time, around which the pest population tends to fluctuate due to biotic and abiotic factors and in the absence of permanent environmental changes.
Damage boundary (DB):- The lowest level of damage which can be measured. Provides sufficient time for control measures.
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Stages in crop protection to leading IPM: - 1 Subsistence phase : Only natural control, No insecticide use. 2 Exploitation phase : Applying more pesticides, growing High Yielding varieties and get more yield and returns. 3 Crisis phase : Due over use pesticides, problem of resurgence, resistance, secondary pest outbreak, increase in production cost. 4 Disaster phase : Due to increased pesticide use - No profit, high residue in soil - Collapse of control system. 5 Integrated : IPM integrates ecofriendly methods to optimize control Management Phase rather than maximize it.
Constrains in IPM - Institutional constraint- IPM requires interdisciplinary approach to solve pest problem. Lack of coordination among different institution is a constraint. Research programme based on farmer’s needs is lacking. Informational constraint-Lack of information on IPM among farmers and extension worker. Lack of training on IPM. Sociological constraint- Some farmers feel it is risky to adopt IPM compared to use of pesticides alone. Our farmers are habituated to using more pesticides. Economic constraint- Lack of funds for training farmers and extension workers on the use of IPM. Political constraint- Vested interest associated with pesticide trade and Pesticide subsidy by Government.
Tools/Methods of IPM- Preventive methods of IPM- Host plant resistance. Legal control (Plant Quarantine). Cultural control. Curative methods of IPM- Physical methods. Mechanical methods. Chemical methods. Biological methods. Insect Growth Regulator (IGR)
Preventive methods can be used, irrespective of the level of pest incidence. It can be followed as a routine, even if the pest is at a low level. Curative methods have to be followed only when the pest attains economic threshold level (ETL).
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Different Methods of Pest Control or Tools of IPM
Natural Control Artificial Control (Applied control/ Tools of IPM)
Abiotic factors Biotic factors (Density independent) (Density dependent)
(1. Food 2. Shelter 3. Natural Enemies)
Climatic Topographical
1) Mountains 2) Soil properties 3) Ocean (Water resources) 4) Deserts
1) Temp 2) Humidity 3) Rainfall/ Moisture 4) Air 5) Sunlight etc.
1. Cultural control 2. Mechanical control 3. Physical control 4. Biological Control 5. Legal Control 6. Chemical Control
Recent trends in pest control
1. Ionizing /radiation 2. Chemosterilants 3. Pheromones 4. Genetic manipulation 5. Insect attractants / Repellants etc.
A) HOST PLANT RESISTANCE
Definition: - The ability of some varieties to produce good quality yield than ordinary varieties at the same level of insect population. R.H. Painter (1968): He defined as relative amount of heritable quality possessed by a plant which influences the ultimate degree of damage done by the insect. He also referred as a Father of HPR. R.H. Painter (1936, 1941) classified the mechanisms of resistance into (i) Non preference (ii) Antibiosis (iii) Tolerance.
. Mechanism of Insect Resistance:-
Antixenosis (Non-preference): - It results from some morphological characters like- i) Absence of attractant, ii) Presence of repellent and Allelochemicals / morphological characters. It is used to denote the group of plant characters and insect responses that keep away an insect from using a particular plant (or) variety, for oviposition, food (or) shelter (or) combination of the three (Painter, 1951). It is proposed by Kogan and Ortman (1978). Morphological characters include plant character such as (1) trichrome, (2) surface waxes, (3) hardiness of plant tissues, (4) thickening of cell walls and 15
(5) cuticle, (6) rapid proliferation of tissues, (7) colour, and shape etc. E.g. Trichrome in cotton - resistant to whitefly, Wax bloom on crucifer leaves - deter feeding by DBM Plant, shape and colour also play a role in non- preference, Open panicle of sorghum - Supports less Helicoverpa.
Antibiosis: - Adverse effect of host plant on the biology of insects. This is due to the presence of toxic metabolites - alkaloids, glucosides, anions Absence / insufficiency of essential nutrients unbalanced proportion of nutrients Presence of antimetabolites that renders some essential nutrients unavailable to insect. Presence of enzymes inhibits normal process of food digestion and consequently utilization of nutrients. Sr. Name of toxic metabolites Resistant against No. 1 Salicylic acid in rice stem Rice stem borer 2 Gossypol in cotton seed American bollworm, Helicoverpa armiger larvae 3 Sinigrin in Aphids, Myzus persicae 4 Cucurbitacin in cucurbits Cucurbit fruit flies 5 DIMBOA (Dihydroxy methyl European corn borer, Ostrinia benzoxazin) nubilalis
Tolerance: - ability of host plant to withstand and give good quality yield even if the sufficient infestation of insects are observed. Tolerance has no adverse effect on the insects. Known component of this form of resistance includes. i) General vigour of plant, ii) Compensatory plant growth in individual plant / population, iii) Wound healing, iv) Mechanical supports in tissue and organs v) Changes in photosynthetic partitioning.
Avoidance or Escape: - Escape of a variety from insect attack either due to earliness or its cultivation in the season where insect population is very low.
Advantages of HPR as a component in IPM Specificity: Specific to the target pest and Natural enemies unaffected. Cumulative effect: Lasts for many successive generations. Eco-friendly, No pollution and less cost. No effect on man and animals. Easily adoptable: High yielding insect resistant variety easily accepted and adopted by farmers. Effectiveness: Resistant variety increases efficacy of insecticides and natural enemies Compatibility: HPR can be combined with all other components of IPM. Decreased pesticide application: Resistant varieties require less frequent and low doses of insecticide.
Types of Resistance- 1. Monogenic resistance: Controlled by single gene. Easy to incorporate into plants by breeding Easy to break also. 2. Oligogenic resistance: Controlled by few genes 3. Polygenic resistance: Controlled by many gene. 4. Major gene resistance: Controlled by one or few major genes (vertical resistance) 16
5. Minor gene resistance: Controlled by many minor genes. The cumulative effect of minor genes is called adult resistance or mature resistance or field resistance. Also called horizontal resistance. 6. Vertical resistance: Effective against specific biotypes (specific resistance) 7. Horizontal resistance: Effective against all the known biotypes (Nonspecific resistance) 8. Pureline resistance: Exhibited by liens which are phenotypically and genetically similar. 9. Multiline resistance: Exhibited by lines which are phenotypically similar but genotypically dissimilar. 10. Cross resistance: Variety with resistance incorporated against a primary pest, confers resistance to another insect. 11. Multiple resistances: Resistance incorporated in a variety against different environmental stresses like insects, diseases, nematodes, heat, drought, cold, etc.
B) CULTURAL CONTROL/METHODS
Regular farm operations or Cultivation practices, employed in a manner that destroy the insects or prevent them from causing injury.
Tillage operations – Ploughing & other tillage operations expose the insects to upper soil surface which are picked by birds or destroyed by heat. E.g. Bihar hairy caterpillar, fruit fly, gram pod borer. It also helps in removal of weeds which may serve as host for insects.
Crop rotation – Practice the crop rotation in such a manner which will break the continuous supply of food to the major pests of that crop. Growing of non-host crop reduces the pest attack on crop. Okra followed by cotton increases the pest attack.
Trap cropping – The trap crops are those crops which are used to control the pest of main crop. Trap crop plants are harvested early or used as a fodder. Okra is good trap crop for cotton to attract Jassids & spotted bollworms.
Sanitation of field – removal & destruction of all undesirable plants, plant debris, weeds & clean cultivation of field. Insects use the plant residues, weeds as a host & increase the pest attack in next season. E.g. sugarcane borers, Jowar stem borer, etc.
Time of sowing/planting – By adjusting time of sowing infection of some pests can be prevented. If egg laying period of a pest is avoid; young plants can be establish before the attack starts. E.g. Early sowing of kharif Jowar to escape from attack of Jowar shoot fly.
Use of resistant varieties – some morphological or genetic factors associated with the variety make the variety resistant for some pests. E.g. Deshi cotton is more resistant to Jassids whitefly & bollworms than American cotton.
Other cultural methods – management of seed rate, pruning, clipping of tips in rice, earthing-up & flooding like cultural practices help to control the pest incidence on the crop. E.g. flooding rice nurseries to eliminate attack of armyworms. Clipping of rice tips at the time of transplanting to eliminate egg masses of stem borer.
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. Merits: - 1) It not increase the production cost. 2) Environmentally safe. 3) It is well-matched with other methods of pest control. 4) It gives least chance of insect development. . Demerits: - 1) Knowledge of ecology & biology is essential. 2) The control measures should be taken well in advance. 3) It should be supplemented with other methods.
C) MECHANICAL CONTROL/METHODS
The method with which insect population is directly beat by mechanical devices or manual operations. Hand picking & destruction: - Insects are picked out & destroyed from the crops. This method is applied when the insects are in large number & easily accessible to picker. By use of hand nets – e.g. butterflies, moths, grasshoppers, etc. By use of iron hook – e.g. rhinoceros beetles from coconut. Beating with brooms – e.g. locust Shaking of plants – Shaking of babul& neem to collect adult beetles of white grub. Sieving and winnowing – used for insects pest of stored grains. E.g. grubs of Khapra beetle. Rope dragging – Passing of rope across the rice crop to dislodge caseworms over the standing water which then drained out to collect the pests at corner of field. Mechanical exclusion or provision of preventive barriers: - Collar around the plants – Paper & tin collars around potato & tobacco to protect from cutworms. Tin bands – fixed over coconut to prevent damage by the rats. Sticky bands – oily bands around mango tree to prevent upward movement of mealy bugs. Trenches around fields – migration of rice armyworms prevented by digging 60×60cm trenches. Bagging of fruits – fruit is covered by bags to protect from fruit sucking moth. Use of ant pans – use of four leg rack in vessels containing water to prevent from ants. Screening of houses – screening the windows, doors, etc. to prevent from mosquitoes. Bird scarer – device used to scare away the birds by explosive sounds called bird scarer. Use of Mechanical Devices: - Light traps – Light is used to attract the insects. E.g. moths, beetles etc. Air suction traps – the traps are fixed in godowns against stored grain pests. Use of flame thrower – burning of locust adults or hoppers with the help of flame. 18
. Merits:- 1) Insect population is directly hit by mechanical devices or manual operations. 2) Environmentally safe. 3) Highly special equipment not required. 4) They are economically good & generally popular. 5) It is more useful in highly pest populated areas. . Demerits: - 1) It requires more time to get result i.e. it is time consuming method.
D) PHYSICAL CONTROL/METHODS
Use of the physical forces or factors of environment for the eradication of insects.
Application of Heat – Heating of the empty godowns above 50°c kills the hibernating stored grain pests. Exposing infested grains to the sun in summer also kills stored grain pests. Flame thrower is used to control the locust. These methods are ineffective on large areas & cannot be apply commercially.
Application of cold – refrigeration at 5-10°c of edibles including dry fruits will kill the insect. Many insects fail to multiply below 10°c. Potato is stored at low temperature.
Manipulation of moisture – By draining away the stagnant water mosquito’s reproduction stops. Reducing the moisture content of grains below 8% can save from most of the insects.
Radio activity – High frequency radio waves generate about 80°c temperature in grains to kill weevils. Male insect can make sterile by gamma radiation.
Manipulation of soil – Steam sterilization of soil is done to kill soil insects and nematodes.
Sound – Exposure of insects to ultrasonic waves of 100 kilocycles for 4-30 minutes at 500 watts has been found to be lethal to most of insects.
. Merits: - 1) It gives immediate results. 2) These methods are generally popular & believable to farmers. 3) Insects are killed by physical action hence environmentally safe.
. Demerits: - 1) These methods are time consuming & costly. 2) These methods are useful only when much more damage has done. 3) Special equipment is required for heating & refrigeration.
E) BIOLOGICAL METHOD
Destruction, regulation or suppression of undesirable insects, other animals or plants by introduction, encouragement or artificial increase of their natural enemies.
Paul Debach (1973) - The study and utilization of parasitoids, predators and pathogens for the regulation of pest population densities. 19
o Predators: Predators are free living organisms that feed on living insects & consume more than one individual during their lifespan. They attack on prey at larval & adult stage. E. g. Lady Bird beetle, Green lace wing, Mantid, Dragon fly, Syrphid fly etc.
o Parasitoid: An insect parasite of an arthropod that is parasitic in its immature stages killing the host in the process of development and adults are free living. E. g. Trichogramma spp., Apanteles flavips, Epiricania meloneuca, Capidosoma koeheleri, Chilonus blackberni, Braconid wasps etc.
o True Parasites: Parasites are organisms which live on other organisms for getting food & shelter. The association of parasite and host known as parasitism. A parasite weakens or kills the host while feeding requires only one part of one host to reach maturity. E.g. ticks, lice, Bed bugs, Protozoa, Nematodes, Mosquitos etc.
Differentiating points between True Parasite, Predator and Parasitoids Sr. Properties True Parasite Parasitoids Predator No. 1 Size Smaller than host Same as that of host Larger than host Only larvae adults are free 2 Feeding stages Larvae and adults living (Feed on nectar of Larvae and adults flowers ) 3 No. of host needed One One More than one 4 Injury to the host Feed without killing Paralyze to oviposit & kill Kill to devour Functions at low Functions at low host Functions at higher 5 Activity host density, so density, so efficient host density efficient 6 Host specificity Great Great Not so great 7 Suitability for BC Not suited Best suited Suited Trichogramma spp., Apanteles E. g. Lady Bird Ticks, lice, flavips, Epiricania beetle, Green lace Bedbugs, Protozoa, 8 Examples meloneuca, wing, Mantid, Nematodes, Capidosoma koeheleri, Dragon Mosquitos etc. Chilonus blackberni, fly, Syrphid fly etc. Braconid wasps etc.
History of Biological Control- The term biocontrol first time used by H. S. Smith in 1919. He is also referred as father of biocontrol. Paul Debach (1973) - He is a pioneer worker in biocontrol. Ancient times - In China Pharaoh’s ant was used to control stored grain pest. Red ant al so used to control foliage feeding caterpillar, 1762 - ‘Mynah’ bird imported from India to Mauritius to control locust, 1770 - Bamboo runways between citrus trees for ants to control caterpillar. November 1888 - First well planned and successful biological control attempt made - In California (USA) Vedalia beetle (Rodolia cardinalis) introduce from Australia to control of cottony cushion scale, pest of citrus, by the scientists Mr. C.V. Riley & Mr. Albert Koeble. This is the first classical example of biological control. 1898 - First introduction of natural enemy into India- 20
1898 - A coccinellids beetle (Australian lady bird beetle), Cryptolaemus montrouzieri was imported into India from Australia and released against coffee green scale, Cocus viridis. Even today it is effective against mealybugs in South India. 1920 - A parasitoid Aphelinus mali introduced from England into India to control Woolly aphid on Apple, Eriosoma lanigerum. 1929-31 - Rodolia cardinalis (common names Vedalia beetle or cardinal ladybird) is a species of ladybird beetle that is sometimes described as endemic to Australia imported into India (from USA) to control cottony cushion scale Icerya purchase on Wattle trees. Regional Station of Commonwealth Institute of Biological Control (CIBC) established at Bangalore in 1957. Presently Project Directorate of Biological Control (PDBC) Bangalore looks after Biocontrol in India. Recently it called as International Center for Agricultural Important Insects in 2006.
Characteristics of ideal parasitoids/Qualities of an effective natural enemy: - Adaptability: It should be Adapted to varied environmental condition & survive in all habitats of pests. Host specific: It should be Monophagous and should be narrow host range. Fast multiplication: Multiply faster than the host, Short life cycle with high fecundity and high female: male ratio. High host searching capacity. Easy rearing and mass multiplication/culturing in laboratory. Disperse quickly in locality. It should be free from hyper parasites. It should not harmful to other beneficial species and plant species. It should withstand refrigeration. It should be small and tiny.
Types of parasites - 1) Primary parasites: -The parasites attack on crop pests. 2) Secondary parasites: -The insects which parasitize the primary parasites of pest called secondary parasites. 3) Tertiary parasites: -The parasites attack on secondary parasites. 4) Hyperparasites:-All parasites that are parasite upon other parasites are collectively called as Hyperparasites. 5) Super parasitism: -It is a type of parasitism where more individuals of the same species are present in a single host they can complete their development in normal way. E. g. Larva of pin sawfly carry tachinid fly. 6) Multiple parasitisms: - It is a type of parasitism where the host is attacked by two or more species of parasitoids. E.g. Ecto parasitoid - Feed externally e.g. Bracon brevicornis Endo parasitoid - Feed internally e.g. Chelonus blackburni.
Methods/ Techniques in Biological Control:
1) Conservation and encouragement of indigenous natural enemies – It refers to avoid use of those pest control measures that destroy natural enemies. It can be achieved by use of selective insecticides which do not kill the natural enemies and development of resistant strains of parasite to pesticides. E. g. Endogramma of 21
Trichogramma spp. this is resistant to Endosulfan. Avoidance of those cultural practices which are harmful for natural enemies. Preservation of inactive stages of natural enemies.
2) Importation or Introduction – Natural enemies are introduced from other areas into a new locality (mainly to control introduced pests) The organization which helpful for finding exotic predator like- Commonwealth Institute of Biocontrol- Trinidad, West Indies International Organization for Biocontrol of noxious animals and plants- Zurich, Switzerland International Center for Agricultural Important Insects- Bangalore, India
3) Augmentation- It includes activities designed to increase the numbers or effect of existing natural enemies. Propagation (mass culturing) and release of NE to increase its population. It may be two types, Inoculative release: This type of release may be made as infrequently as once a year or season to re-establish a species of natural enemies and Inundative release: It involves mass culture and release of natural enemies to suppress the pest population directly.
Natural enemies used in Biological control:
a) Insects:
Predaceous insects – Chrysoperla carnia (Green Lace Wing) feed on Aphids, Jassids, whitefly, etc. Cryptolaemus montrouzieri (Australian Ladybird beetle) feed on mealy bugs. Coccinella septumpunctata (Ladybird beetle) feed on aphids Syrphid fly - Feed on different insects. Vedalia beetle feed on cottony cushion scale. Dipha (Conobathra) aphidivora feed on sugarcane wooly aphids.
Parasitic insects - (Parasitoids)- Egg Parasitoids - Trichogramma japonicum: parasite of stem borer of paddy. Trichogramma chilonus - parasite of Cotton bollworms & sugarcane stem bores. Larval Parasitoid - Bracon kirkpatrickii & Apanteles angaleti parasite of cotton bollworms. Egg-Larval Paranoids -Capidosoma koeheleri & Chilonus blackberni- parasite of potato tuber moth. Nymphal & Adult Parasitoid -Epiricania meloneuca- parasite of sugarcane pyrilla. Aphelinus mali - parasite of Apple wooly aphids.
b) Predatory vertebrates: Birds – Useful birds which destroyed crop pests includes king-crow & myna. Ducks used in rice to control bug. Fishes – Destroy large number of mosquito larva. Frog – Destroy paddy stem borer. Toad & wall lizard – Live on insects such as termites‟ crickets, grasshoppers, bug, etc. Snakes –feed on rats.
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c) Nematode parasites: 46 nematodes species, parasitizing various species of beetle, grasshoppers, cockroaches, moths etc. Neoplanctana glaseri used for control of Japanese beetle. Nematodes especially rhabditids are found to have a symbiotic relationship with the bacteria, forming disease complex. E.g. DD-136 Association between the nematode. Neoplanctana caprocapsi and bacterium Acromobacter nimatophilus against Codling moth of apple.
d) Pathogens: Certain microorganism able to causing diseases in insects which includes fungi, bacteria, viruses, protozoa, rickettsia and nematodes. Microbial control: - It is a branch of biological control which deals with study and utilization of microorganism for the suppression of pest population density. The Microbial control first time used by the E. A. Steinhause in 1949 referred as a ‘Father of Insect Pathology’ worked on Muscardine diseases of silkworm.
Entomopathogenic fungi – The fungi which cause disease in insects called as Entomopathogenic fungi. Adults are more affected than larvae to Entomopathogenic fungi. Fungi require high atmospheric humidity to germinate. Fungi get entry through integument, via respiration. Fungus gets entry with the help of aspersoria which is present on conidia. They are usually attack on dipteran insects followed by Hemiptera, lepidopteran &coleopteran. Besides Entomopathogenic fungi the other fungi is also attack on insects like Entomophilic fungi (insect loving) and Entomophagous fungi (feed on insects) E.g. Green Muscardine fungus- Metarhizium anisopliae attack on coconut rhinoceros beetle & sugarcane pyrilla, White muscardine fungus- Beaveria Bassiana against lepidopteran larvae, White halo fungus- Verticillium lecanii on coffee green scale & Entomophthora grylli on grasshoppers.
Entomopathogenic Bacteria – The bacteria cause disease in the insects when they infect through ingestion. Spore forming (Facultative, Crystalliferous) - They produce spores and also toxin (endotoxin). The endotoxin paralyses gut when ingested by insects e.g. Bacillus thuringiensis var. kurstaki effective against lepidopteran & it is stomach poison. Commercial products - Delfin, Dipel, Thuricide Spore-forming (Obligate) - e.g. Bacillus papillae attacking on beetles cause ‘milky disease’. Commercial product - ‘Doom’ against ‘white grubs. Non-spore forming - e.g. Serratia entomophila on grubs
Insect Viruses – There are six families of insect viruses. Among them baculoviridae is important which includes the nuclear polyhedrosis & granulosis are most 23
lethal & promising viral insecticides which cause disease in Lepidoptera larvae. Insect viruses have great potential for field because of their specificity & effectiveness against important crop pests. E.g. NPV (Nucleo polyhedrosis viruses) - e.g. HaNPV (Helicoverpa armigera nuclear polyhedrosis viruses) against American bollworm, SlNPV (Spodoptera litura nuclear polyhedrosis viruses) against tobacco leaf eating caterpillar. GV (Granulovirus viruses)- e.g. CiGV (Chillo infuscatellus Granulovirus viruses)
e) Protozoa – The role of protozoa as microbial agents in artificial control is limited because of difficulties in their mass multiplication for field release. E.g. Nosema bombycis on silkworm and Perezia pyraustae on European corn borer.
f) Biological control of weeds- Lantana camera (Ghanery) control by Lantana seed fly Agromyza lantinae. Mexican/parthenium beetle, Zygogramma bicolorata effective against parthenium. Leaf eating weevils, Neochetina spp. feed on water hyacinth.
. Advantages of biological control: - 1) Complete control over large area is possible. 2) Co-operative efforts of farmers of a locality are not necessary. 3) It is cheap method as it useful to long time. 4) Biological agents will survive as long as the pest is survived. 5) It is environmentally safe. 6) There is no pest resistance problem.
. Demerits biological control: - 1) It is slow process & takes long time. 2) Not suitable where immediate control required. 3) Effectiveness depends upon climate. 4) Multiplication on large scale is difficult i.e. storage not possible. 5) The work cannot be restricted at a particular area. 6) If alternate hosts are present it may not give desired effect. 7) Work of biological agents may affect due to the Hyperparasites.
F) LEGAL METHODS
It is defined as way of controlling pests by imposing various legal restrictions in order to prevent the entry of foreign pest or to prevent the spread of pests within country. Pests Accidentally Introduced into India (Exotic pests) Pink bollworm - Pectinophora gossypiella Cotton cushion scale - Icerya purchase Wooly aphid of apple - Aphelinus mali San Jose scale - Quadraspidiotus perniciosus Potato tuber moth - Pthoromia operculella 24
Cyst (Golden) nematode of potato - Globodera sp. Giant African snail - Acatina fullica Spiraling whitefly - Aleyrodicus disperses Foreign Pests from Which India is Free- Mediterranean fruit fly, Cotton boll weevil, Codling moth of apple etc. Quarantine - Isolation to prevent spreading of infection. Plant Quarantine - Legal restriction of movement of plant materials between countries and between states within the country to prevent or limit introduction and spread of pests and diseases in areas where they do not exist.
Pest Legislations 1905 - ‘Federal Insect Pest Act’ - first Quarantine act against San Jose scale in USA. 1912 - ‘US Plant Quarantine Act’ 1914 - ‘Destructive Insects and Pests Act’ of India (DIPA) 1919 - ‘Madras Agricultural Pests and Diseases Act’ 1968 - ‘The Insecticides Act’
Different legislative measures: Legislation to prevent the introduction of new pest, diseases & weeds from foreign countries. Legislation to prevent the spread of already established pest, diseases & weeds from one part of country to another. Legislation to enforce upon the farmers for application of effective control measures to prevent the damage by already established pest, diseases & weeds. Legislation to prevent the adulteration & misbranding of insecticides & to determine the permissible residue tolerances in food stuffs. Legislation to regulate the activities of pest control operations & the application of hazardous insecticide.
Categories of legal Methods/Different Classes of Quarantine:
1) Foreign quarantine: Legislation to prevent the introduction of new pest, diseases & weeds from foreign countries. To prevent the entry of foreign pests, in the world have restrictions on the import of infested or infected plant materials under the provisions of quarantine laws. These plants materials examined at each seaports like Mumbai, Calcutta, Cochin & Chennai and airport like Amritsar, Mumbai, Calcutta, and Chennai & New Delhi. These stations operate under the provision made under the Government of India’s Destructive Insects and Pests Act of 1914. The “Phytosanitary Certificate” (PSC) should be issued by the officer of Department of Agriculture of exporting country as to their freedom from pest & diseases. The Central Directorate of Plant Protection and Quarantine was established in 1946 - for inspection of export and import of agricultural commodities. Restriction imposed on the importation of; Sugarcane setts - to prevent West Indies sugar weevil, Coffee seeds - to prevent coffee berry borer and Cotton seeds - to prevent cotton boll weevil.
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2) Domestic quarantine: Legislation to prevent the spread of already established pest, diseases & weeds from one part of country to another. “The Bombay Agricultural Pests and Diseases Act” was passed in 1947 and accordance with this the domestic quarantine in the state is being implemented. The Directorate of Plant Protection, Quarantine and storage is overall In-charge for this work and it operates through several Inter-State check posts. So far Cottony cushion scale and San Jose scale were covered under this type of quarantine.
3) Pest Act: Legislation to enforce upon the farmers for application of effective control measures to prevent the damage by already established pest, diseases & weeds. Under the provision of “The Bombay Agricultural Pests and Diseases Act” State Government may declared that certain pest is injurious in given area & carry out preventive and remedial measures in order to eradicate the pest within a specified period.
4) Insecticides Act: Legislation to prevent the adulteration & misbranding of insecticides & to determine the permissible residue tolerances in food stuffs. The manufacture of insecticides should resister themselves stating the name and address of the manufacturer, the brand and trade name of the insecticide, active ingredient and other constituents of the product to be manufactured, its net contents in an unit pack which should also carry in detailed directions for use including the antidote against the insecticide in case of poisoning. The container should carry “poison label” with warning or caution statement. The Government of India passed the Insecticide Act, 1968 (No. 46 of 1968) on 2nd September, 1968 to regulate the import, manufacture, sale, transport, distribution and use of insecticides with a view to prevent risk to human beings and animals. The Insecticides Rules framed under the Insecticide Act, 1968 (46 of 1968) came in to force in 1st Jan, 1971.
Licensing authority - In Maharashtra the commissioner of Agriculture, M.S. Pune is the Licensing authority. However on behalf of him, Chief Plant Protection Officer, MH State, Pune act as licensing officer for manufacture and formulation of pesticides and for sale and stock concerned Divisional Superintending Agriculture Officer acts as licensing officer.
Appellate Authority - any appeal against any decision of the licensing officer is made to Appellate Authority. In MH, Joint Director of Agriculture (Extension), Department of Agriculture M. S. Pune acts as Appellate Authority.
Insecticides Inspectors (Quality Control Officers) - The District Agriculture Officer of Z.P. & Sub-divisional Agricultural Officers of Department of Agriculture can collect the insecticides samples from the shops to ascertain their purity through insecticidal residue laboratories.
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G) CHEMICAL CONTROL Chemical Control: Management of insect pests using chemical pesticides is termed as chemical control. Or Pest control with the help of various chemicals is called as chemical control. Pesticides: - The chemicals which applied for control of insect pests are called as pesticides. History of insecticides development Year Chemicals Discovered 900 Arsenites used in China (Inorganic compound) 1690 Tobacco extract used in Europe (Plant/natural product) 1787 Soaps used in Europe 1858 Pyrethrum was first time used for insect control in USA 1867 Paris Green in US 1874 DDT synthesized by Zeidler 1883 Bordeaux Mixture used in France 1892 Lead arsenate was used for control of Gypsy moth in USA 1925 Dinitro compounds used (First synthetic organic insecticide) 1939 Discovered of insecticidal property of DDT by Paul Muller in Switzerland. (Awarded Nobel Prize in 1948) 1941 BHC used or discovered the insecticidal property in France and UK (in 1942) (BHC is presently called as HCH) 1944 Parathion (Organophosphate) discovered by Gerhard Schrader in Germany 1945 Chlordane (Cyclodienes compound) used in Germany 197 Carbamate insecticides in Switzerland 1962 Miss Rachel Carson’s wrote the book name ‘Silent Spring’ in US which gives the impact of insecticides on environment. 1967 First JH mimic (Juvenile Hormone mimic) used in US (Insect growth regulator) 1970 Development of synthetic pyrethroids (UK) (Fast degradation) (Effective at very low doses) 1980 Discovery of Avermectins (derived from bacteria). Effective at low dose. Fast degradation. 1990 Discovery of newer groups like (1) Neonicotinoids (Imidacloprid), similar to natural nicotine, (2) Spinosyns (e.g. Spinosad) derived from actinomycets
Generation of insecticides Year Generation Compounds 1939-1942 First Generation Insecticides BHC and DDT 1944-1947 Second Generation Organophosphates and Carbamate Insecticides 1967 Third Generation Insecticides Hormonal insecticides, JH mimic insect growth regulators 1970’s Fourth Generation Synthetic pyrethroids Insecticides
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Ideal Qualities of an Insecticide:- Kill the target insect effectively and quickly. Be less toxic to natural enemies. Be less toxic to honey bees, soil microorganisms. Be less toxic to fishes and mammals. Less hazardous and less toxic during handling or accidental consumption by human beings. Quickly degradable in environment and should be less persistent (Residues should be very less) Should not cause resurgence of the target insect (i.e. Increase in population of target insect) e.g. Chlorpyriphos causes resurgence of brown plant hopper on rice. Should not cause outbreak of secondary pest on a minor pest by killing the natural enemies. Should have a complex mode of action against which resistance development will take more time. E.g. Azadirachtin from neem tree has complex action. Should have a longer storage life or shelf life. It is advantageous to select an insecticide which can kill a relatively broad spectrum of target pests. It should be cost effective (High benefit/Cost ratio) and safe to use (High benefit/Risk ratio)
Impact of Pesticides in Agroecosystem- The following are some problems caused by pesticides in agro-eco system; Pesticide residues Insecticide resistance Insect resurgence secondary pest outbreak Toxicity to non-target organism
o Pesticide residues- The pesticide that remains in the environment after application causes problems to humans and non-target organisms (Already dealt in theory - Read) e.g. Residues of DDT, HCH in milk, vegetable above MRL.
o Insecticide resistance- Insecticide resistance is the development of an ability to tolerate a dose of insecticide, which would prove lethal (kill) to majority of the individuals of the same species. This ability is due to the genetic change in pest population in response to pesticide application. It causes Simple resistance (Insect develops resistance only against the insecticide to which it is exposed) and Cross resistance (Insect develops resistance not only to exposed insecticide but also to other related insecticides to which it is not exposed). Insecticide resistance in insect pests in India Sr. Name of pest Common name Insecticides to which resistant No. 1 Aphis craccivora Aphid Carbamates, OP, Cypermethrin 2 Bemesia tabaci Whitefly Endosulfan, Monocrotophos 3 Helicoverpa armigera Cotton boll worm OP, Synthetic pyrethroids, Bacillus thuringiensis 4 Plutella xylostella Diamond back moth Abamectin, Bt, OP compounds 28 o Pest Resurgence- Tremendous increase in pest population brought about by insecticides despite good initial reduction in pest population at the time of treatment. E.g. Quinalphos, Phorate - Cause resurgence of BPH in rice and Carbofuran - Leaf folder in rice.
o Secondary pest outbreak- Application of a pesticide against a major pest kills the natural enemies of minor or secondary pest. This causes the outbreak of a secondary pest. E.g. Use of synthetic pyrethroids against bollworms in cotton killed natural enemies of whitefly causing an outbreak of whitefly which was a minor pest till then. o Toxicity of non-target organisms Natural enemies : Predators and parasitoids are killed loading to pest outbreak Bee toxicity : Bees are important pollinators. Killing bees reduce crop productivity Soil organisms : Soil organisms like microbes, arthropods, earthworm, etc. are required for maintaining soil fertility. These are killed by some pesticides e.g. DDT, HCH Fishes : Pesticides from treated surface run off to nearby lakes and kill the fishes
Hazards Caused by Pesticides: - The adverse effect caused by pesticides to human beings during manufacture, formulation, application and also consumption of treated products is termed as the hazard. Pesticide hazard occurs at the time of; Manufacturing and formulation, Application of pesticides and Consumption of treated products. Examples of hazards caused by pesticides- In Kerala, in 1953, 108 people died due to parathion poisoning. ‘Bhopal Gas Tragedy’ in 1984 at Bhopal where the gas called Methyl isocyanate (MIC) (an intermediate involved in manufacture of Carbaryl leaked killing 5000 people and disabling 50,000 people. Totally 2, 00,000 persons were affected. Long term effects like mutagenic and carcinogenic effects are felt by survivors. Cases of Blindness, Cancer, Liver and Nervous system diseases in cotton growing areas of Maharashtra where pesticides are used in high quantity. Psychological symptoms like anxiety, sleep disturbance, depression, and severe head ache in workers involved in spraying DDT, Malathion regularly. Endosulfan - causing problem due to aerial spraying in cashew in Kerala and the pesticide was banned in Kerala as early as 2001.
Safe handling of pesticides:
Storage of pesticides: Store house should be away from population areas, wells, domestic water storage, tanks. All pesticides should be stored in their original labeled containers in tightly sealed condition. Store away from the reach of children, away from flames and keep them under lock and key.
Personal protective equipment: Protective clothing that covers arms, legs, nose and head to protect the skin. b) Gloves and boots to protect hands and 29
feet. Helmets, goggles and facemask to protect hair, eyes and nose. Respirator to avoid breathing dusts, mists and vapour.
Safety in application of pesticides: Safe handling of pesticides involves proper selection and careful handling during mixing and application.
a) Pesticide selection : Selection of a pesticide depend on the type of pest, damage, losses caused, cost etc.
b) Safety before application: o Read the label and leaflet carefully. o Calculate the required quantity of pesticides. o Wear protective clothing and equipment before handling. o Avoid spillage and prepare spray fluid in well ventilated area. o Stand in the direction of the wind on back when mixing pesticides. o Do not eat, drink or smoke during mixing. o Dispose-off the containers immediately after use.
c) Safety during application: o Wear protective clothing and equipment. o Spray should be done in windward direction. o Apply correct coverage. o Do not blow, suck or apply mouth to any spray nozzle. o Check the spray equipment before use for any leakage.
d) Safety after application: o Empty the spray tank completely after spraying. o Avoid the draining the contaminated solution in ponds, well or on the grass where cattle graze. o Clean the spray equipment immediately after use. o Decontaminate protective clothing and foot wear. o Wash the hands thoroughly with soap water, preferably have a bath. o Dispose-off the containers by putting into a pit.
Classification of Pesticides/Pesticides Groups- The pesticides are generally classified into various groups; Based on organism against which the compounds are used, Based on chemical nature, Based on mode of entry and Based on mode of action.
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1. Based on organism against which compounds are used- Sr. Name of insecticides Definition with examples No. 1 Insecticides Chemicals used to kill or control insects. E.g. Carbaryl, malathion etc. 2 Rodenticides Chemicals used to kill the rodents called rodenticides. E.g. Zinc phosphide etc. 3 Acaricides/Miticides Chemicals used to kill the mites, ticks and spider called Acaricides. E. g. Dicofol, Properguite 4 Avicides Chemicals used to repel/kill the birds. E.g. strychnine, DRC-1339, Anthraquinone etc. 5 Molluscicides Chemicals used to kill the snails and slugs. E.g. Metaldehyde 6 Nematicides Chemicals used to control nematodes E.g. Ethylene dibromide 7 Fungicides Chemicals used to control plant diseases caused by fungi. E.g. Copper oxychloride 8 Bactericide Chemicals used to control plant diseases caused by bacteria. E.g. Streptomycin sulphate 9 Herbicide Chemicals used to control weeds. E.g. 2,4,D 10 Algaecide Chemical designed to kill and prevent algae growth. Copper sulfate, copper chelates, endothall, sodium carbonate peroxyhydrate. 11 Arboricides Any herbicide intended to kill trees or shrubs. 12 Piscicides Chemical substance which is poisonous to fish. Rotenone, Saponins, TFM, Niclosamide and Antimycin A (Fintrol)
2. Classification based on Mode of entry-
Stomach poison –Insecticides applied on leaves and other parts of plants when ingested get entry in insects & act on digestive system to cause death of the insect. This type of chemicals is limited mainly to the chewing type of insects like grasshopper, beetles, caterpillar etc. The stomach poison should be sufficiently stable, cheap, and palatable for the pest, available in large quantities. These chemicals may be applied in the form of dust or spray or in poison bait. E.g. Bt, Organochlorine and organophosphates insecticides etc.
Contact poison –The toxicant which causes death of insect by means of contact with insecticide. Insecticides get absorb by the sutures, membrane & tracheal system on insect body. This is achieved by direct application of insecticides on pest species. E.g. Nicotine, Pyrethrum, quinalphos, Malathion, synthetic pyrethroids etc.
Fumigants – Toxicant which in its gaseous state or in vapour form penetrate in insect through the tracheal system (respiratory poison) through spiracles & kill the insect. Their application is limited to plants or plant products in air-tight enclosures. E.g. Methyl Bromide, Hydrogen cyanide (HCN), ethylene dibromide, DDVP, Lindane. 31
Systemic poison - Chemicals when applied to plant or soil are absorbed by foliage (or) roots and translocated through vascular system and cause death of insect feeding on plant. It is effective against the pest having sucking type of mouth parts such as aphid, Jassids, thrips, white fly etc. E.g. Dimethoate, Imidacloprid, Phorate, Carbofuran etc.
3. Classification based on mode of action: -
Physical poison – Chemical which can kill insects by following three ways; Asphyxiation – A physical poison kill the insects exert by physical effect through asphyxiation i.e. exclusion of air called physical poison. E.g. effect of heavy oil & Tar oil on scale insects. Moisture stress – Loss of moisture from insect body by inert dust, charcoal, activated clay, ash etc. Mechanical injury – Epicuticle of insect gets lacerated by abrasive dust like aluminum oxide & this may cause water loss.
Protoplasmic poison – Toxicant responsible for precipitation of protein, destruction of midgut epithelium called as protoplasmic poison. E.g. Heavy metals like mercury, copper, Fluorine. Respiratory poison – The chemical which block cellular respiration, inactivation of respiration & respiratory enzymes. This is known as anoxia. E.g. Hydrogen cyanide (HCN), Carbon monoxide (CO). Nerve poison – The chemicals which affect the nervous system of the insect or Chemicals inhibit the production of acetylcholinesterase enzyme in insects called as nerve poison. E.g. organophosphate, carbamate, organochlorines, pyrethrum and nicotine. Chitin inhibition - Chemicals inhibit chitin synthesis. E.g. Diflubenzuron.
4. Classification based on the Chemical nature of insecticide: -
INSECTICIDEDS
Inorganic compounds Organic compounds
Arsenicals, Hydrocarbon oils Animal origin Plant origin Synthetic organic Fluorine, Petrol, Kerosene (Nereis toxin) Nicotine compounds compounds, oil, Coal tar oil etc. alkaloids Organochlorines Sulphur, Pyrethroids Organophosphates Lime & sulphur, Rotenoids Carbamates Barium carbonate, Neem extract Synthetic Zinc phosphide Rynia pyrethroids Novel insecticides
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Inorganic Compounds: -The insecticides derived from naturally occurring elements which do not contain carbon. It comprises compounds of mineral origin and element Sulphur and phosphorus. They are stable, non-volatile and soluble in water. Many of them are persistent and because of their residual persistent high mammalian toxicity it’s a limited used. Both boric acid and silica used in baits for controlling the household pests like cockroaches and ants. 1) Arsenicals -These are stomach poisons formed of toxic compounds of non-toxic elements arsenic. The toxicity of arsenic to insects, bacteria, and fungi led to its use as a wood preservative. They are phytotoxic & not applied on plants. It is used in poison baits. They kill the insects due to the inhibition of respiratory enzyme. They are more stable and not harmful to plants. Arsenic is used as a feed additive in poultry and swine production, to increase weight gain, improve feed efficiency, and to prevent disease. Arsenic is intentionally added to the feed of chickens raised for human consumption. Organic arsenic compounds are less toxic than pure arsenic, and promote the growth of chickens. The main use of metallic arsenic is in alloying with lead. Lead components used in car batteries. Paris green used as a rodenticide and insecticide E.g. lead arsenate, Calcium arsenate, Sodium arsenate, Paris green etc. 2) Fluorine compounds -They kill the insects more rapidly than arsenicals. They are cheaper & less toxic to higher animals. They are stomach & contact poison. They are irritating to the appendages of insects. These are cheaper and non-toxic to plants and animals. It is also used as additives for water fluoridation, opal glass raw material, ore refining, E.g. Sodium fluoride, Sodium fluosilicate. 3) Sulphur - It is a contact poison. It is available in the form of both formulation dust as well as Wettable powder. It is used as Acaricides as well as fungicide. 4) Lime Sulphur - It is prepared by boiling lime (calcium hydroxide) & Sulphur together in water (1:2). Lime sulfur is sold as a spray for deciduous trees to control fungi, bacteria and insects living or dormant on the surface of the bark. Lime sulfur burns leaves so it is not as useful for evergreen plants. It is used against aphids, mites, San Jose Scale etc. 5) Zinc-phosphide - It is rodenticide used to control rat. It is heavy dark grey powder with disagreeable odour. Baits containing 2 % zinc phosphide are recommended for control of rats. In rats the chemicals reacts with the hydrochloric acids present in the stomach and release phosphine gas which is lethal to the rats. Zinc phosphide is typically added to rodent baits in amount of around 0.75-2%.Such baits have a strong, pungent garlic-like odor characteristic of phosphine liberated by hydrolysis. E.g. Zinphos. 6) Aluminium phosphide- It is a highly toxic inorganic compound. It is used as a rodenticide, insecticide, and fumigant for stored cereal grains. The acid in the digestive system of the rodent reacts with the phosphide to generate the toxic phosphine gas. Aluminium phosphide can be encountered under various brand names, e.g. Celphos, Fostox, Fumitoxin, Phostek, Phostoxin, Quick Phos, Talunex, and Fieldphos. 7) Barium carbonate- It is also acts rodenticide. After ingestion internal bleeding of intestinal tract & kidneys occurred. Barium carbonate (BaCO3), also known as witherite, is a chemical compound also used in bricks, ceramic glazes and cement. 33
Organic Compounds: - These are man-made or extracted pesticides consisting of carbon, hydrogen and chlorine, oxygen, Sulphur, phosphorus and nitrogen. Hydramethylnon is used as an insecticide in the form of baits for cockroaches and ants. Bifenthrin is a pyrethroids insecticide used primarily against the red imported fire ant by influencing its nervous system. 1) Hydrocarbon oils: Oils composed of hydrogen & carbon. It has two groups viz. Mineral oils – These are petroleum oils derived from secondary rocks. E.g. Kerosene, Petrol, Lubricants oil etc. Coal-tar oils – These are creosol oil & green oils are useful for insecticidal purpose. E.g. summer oils, dormant oils, spray oils, supreme spray oils and Borer solution to control bark borer, stem borer. 2) Animal origin insecticides: A toxin isolated from Marine annelids, Lumbrineris heteropoda & Lumbrineris vicirra. i.e. Nereis toxin. Insecticidal properties of Nereis toxin has been found by Nitta in 1934 and it is given by Sakai in 1964. Common name of Nereis toxin is Cartap and Trade name is Padan. It is effective against rice stem borer & cabbage diamond moth. 3) Plant origin insecticides: (Botanicals insecticides/Natural insecticides) Toxicants derived from plants & used in insect control. It includes nicotine, pyrethrum, rotenone, Azadirachtin, Scilliroside, Pongram, Rynia, and Sabadilla. Certain plant products also used as a Nematicides, insect attractants and repellants and as diluents in insecticidal formulation. Nicotine - Tobacco was used in insect control as early as 1763, the principal alkaloid Nicotine was discovered in 1828. The chief source is Nicotiana tabaccum & Nicotiana rustica. 12 alkaloids have been isolated from tobacco and alkaloid Nicotine constitutes 97% of the total alkaloids. Nicotine in leaves of N. tabacumis 2-5%. Nicotine is obtained from leaves and stem of waste tobacco by steam sterilization. It is nerve poison & highly toxic when absorbed through cuticle/trachea. The commercial product is Nicotine sulphate containing 40% alkaloid. It is water soluble. It may be used as a spray or dust. It is effective against soft bodies insects like thrips, hoppers, etc. It is also a neuro-muscular poison in man and animal hence it’s used is discouraged. Neem - The neem tree i.e. Azadirachta indica which is indigenous to India having the various medicinal and insecticidal values. Now days it is assuming as an International Tree. All parts of neem possess insecticidal activity but seeds are main source which is most effective. Neem bark leaves and neem oil as well as extracts with various solvents like ethanol are found effective. Azadirachtin the main active ingredient present in neem with other alkaloids like limonoids and protolimonoids which shown repellent, antifeedants and insecticidal activity. The antifeedants activity against desert locust which is shown by Pradhan et al. in 1962. It is used as growth inhibitor, cause egg sterility & adverse effect on fecundity. It is effective against American bollworm, leaf eating caterpillar, Diamond back moth, and armyworm and sucking pest like leaf hoppers, thrips. Many commercial formulations are available in market like Achook, Bioneem, Econeem, Neemark, Neemazal, Neem oil. 5% Neem Seed Kernel Extract (NSKE) is mostly used in IPM programme. 34
Pyrethroids / Pyrethrums / Pyrethrins - These are extracted from Chrysanthemum flower which contain active ingredients pyrethrum I and II &cinerin I and II. Pyrethrums are dried flower powder of Chrysanthemum, Pyrethrins are all the active toxins of pyrethrum and Pyrethroids are synthetic derivatives of Pyrethrins. All pyrethroids are lipophilic (Fat loving) compounds and insoluble in water. It show higher toxicity against insects & very safe to mammals. These are contact poisons. Synthetic Pyrethroids like Cypermethrine, Permethrin, Deltamethrin, Decamethrine and fenvalerate are effective against soft bodies & lepidopterans insects which are contact and stomach poisons. Allethrin was the first synthetic analogue of pyrethrum developed in 1949.An active ingredient found in mosquito coils is Allethrin. Cyfluthrin is a pyrethroids insecticide and common household pesticide. Pyrethrins bind to sodium channels that occur along the length of nerve cells. Rotenone - It is derived from roots of bean legumes, Derris eliptica. Used in 1848 against leaf eating caterpillar. Rotenone has been used as an organic pesticide dust for gardens. It kills potato beetles, cucumber beetles, flea beetles, cabbage worms, raspberry beetles, and asparagus beetles. The active ingredient i.e. rotenone is isolated by the scientist Geoffroy I 1882. It is a contact and stomach poison. It inhibits respiratory metabolism‟. It is extremely toxic to fish hence used as a nonselective piscide (The chemical which is used to kill the fishes).Rotenone is also used in powdered form to head lice on humans, and parasitic mites on chickens, livestock, and pet animals. Rotenone inhibits the oxidation of NADH to NAD, blocking the oxidation by NAD of substrates such as glutamate, alpha-ketoglutarate, and pyruvate. Rotenone inhibits the mitochondrial respiratory chain between diphosphopyridine nucleotide and flavine. Scilliroside -These are obtained from the bulb of Red Squill, Urginea maritime. The active ingredient presents i.e. Scilliroside which is generally used as rodenticides. It is a stomach poison. It is used to control the rats and mice. Pongramm - These are derived from the plant Pongamia pinnata (Karanj). The active ingredient presents i.e. Pongram has been identified as ‘karanjin’. Karanj oil applied as surface protectant and repellent. It is used against pulse beetle and sucking pests. Sabadilla - It is an alkaloid extracted from seeds of Schoenocaulon officinale. Rynia - It is extracted from stem, roots, leaves and stalks of tropical shrub of Ryania speciosa. Salicaceae, South American plant. It is water soluble powder. Extract contains several structurally related ryanoids including – ryanodine and 9, 21- dehydroryanodine. The extract has a very low acute toxicity to mammals. Used for control of both adults and larval Lepidoptera. 4) Synthetic organic insecticides: - These are dominating the field of pest control today. Historically Dinitrophenols come first in 1925. It includes organochlorine, organophosphate, carbamates and synthetic pyrethroids. a) Dinitrophenols: ((DNOC): - They are Stomach poison with ovicidal effect on eggs of certain insects. It is used as an antiseptic and as a non-selective bio- accumulating pesticide. E.g. Dinocap is a contact fungicide used to control 35
powdery mildew on many crops and is also used as a non-systemic Acaricides. It is also used as an herbicide such as 2-4-D. b) Organic thiocyanates: - It is also known as rhodanide. It cause quick knock down effect. It is contact poison. Common derivatives include potassium thiocyanate and sodium thiocyanate. It is used as an herbicides, fungicides and pesticides E.g. Loro - Used against thrips, mites and aphids. Thanite - Used against housefly and cattle pests. c) Chlorinated hydrocarbons or organochlorines compounds: The group of chemicals composed of carbon, chlorine, and hydrogen. It includes DDT, methoxychlor, dieldrin, chlordane, toxaphene, mirex, kepone, lindane, and benzene hexachloride.
DDT- (Dichlorodiphenyltrichloroethane) - It was synthesized by a German chemist Othmar Zeidlerin 1874. Its insecticidal properties were given by Paul Muller in 1939. The proper chemical name of DDT is 2, 2-bis (P-chlorophenyl) 1, 1, 1- (trichloroethane). It was very effective against flies, mosquitoes, lice and fleas and also used in agriculture and horticulture sector. It has long residual life and persistence in the soil in aquatic environment and also accumulates in plant and animal tissue hence it’s used is banned in agriculture. DDT analogues - DDD (Dichlorodiphenyl dichloroethane), Dicofol (Kelthane) it is an Acaricides that is very effective against spider mite), Methoxychlor (It’s banned). BHC- (HCH) -The proper chemical name of HCH is 1, 2, 3, 4, 5, 6- Hexachloro cyclohexane and common name is benzene hexachloride. It is synthesized by a Michael Faraday in 1825.Its insecticidal properties were given by A.P.W. Dupire in 1941 and F.D.Leicester in 1942.BHC is a mixture five isomers in which gamma isomers were found to have insecticidal properties is known as HCH.A product containing 99% pure gamma isomers called lindane name proposed after Vander Lindane, who was isolate this isomers in 1912.HCH is stomach and contact poison and has fumigant action. Lindane mostly used in control of stored grain pests. Cyclodienes compound -Due to the persistence in the soil, resistance in insect, fish toxicity and serious environmental hazards is being banned insecticides. It includes Endosulfan, Aldrin, Endrin, Dieldrin, Heptachlor and chlordane. Endosulfan -Its insecticidal properties were first discovered by W. Finkenbrinkin1956.It is a stomach and contact poison. It is effective against sucking pests, caterpillars and borers. It is available in the form of dust, EC and granule formulations. Although classified as a yellow label (highly toxic) pesticide by the Central Insecticides Board, India is one of the largest producers and the largest consumer of Endosulfan in the world, of the total volume manufactured in India, three companies- Excel Crop Care, Hindustan Insecticides Ltd, and Coromandal Fertilizers. The toxicity of Endosulfan and health issues due to its bioaccumulation 36
came under media attention when health issues precipitated in the Kasaragod District of Kerala were publicized and the pesticide was banned in Kerala as early as 2001, Later, on a petition filed in the Supreme Court of India, the production, storage, sale and use of the pesticide was temporarily banned on 13 May 2011, and later permanently by the end of 2011. d) Organophosphorus insecticides or organophosphates: They can be considered as esters of phosphoric acid. They comprise a large group of compounds. They are generally acutely toxic to man and animals and they are non-persistent. They have a short residual activity. They are nerve poison which inhibits the cholinesterase enzyme. These are stomach, contact and systemic in activity. It has been used in large scale for agriculture because of its high efficacy against many insects-pests, low mammalian toxicity, short residual activity and little resistance among insect-pests. Insecticides like Dematon, Dimethoate, Phorate, Phosphamidon and Monocrotophos have a systemic action hence it is used against sucking pests. Dichlorovos or 2, 2- dichlorovinyl dimethyl phosphate (commonly abbreviated as DDVP) and Tetraethyl pyrophosphate, (abbreviated TEPP) is an organophosphate, widely used as an insecticide to control household pests, in public health, and protecting stored product from insects. Monocrotophos shows the some acaricidal activity and Dichlorvos shows the fumigant action. Examples - Monocrotophos, Dichlorovos, Triazophos Chlorpyriphos, Profenophos, quinophos, Malathion, Phosphamidon, Fenthion, Methyl parathion, Trichlorofon, Methyl dematon, Ethion, Formothion, Fenitrothion, Dematon, Dimethoate, Acephate, Phorate, Fipronil, Indoxacarb, etc. e) Carbamates: These are ester of carbamic acids. They generally have a short residual activity and a very broad-spectrum effectivity as insecticides, Miticides, nematicides and Molluscicides. These insecticides kill insects by reversibly inactivating the enzyme acetylcholinesterase. Carbaryl - The trade name of Carbaryl is Sevin. It is contact and stomach poison. It is available in the form of dust, granules and Wettable powder formulation. It is very popular in horticulture for pest management. Carbofuran - The trade name is Furadan. It is systemic in action hence effective against sucking pests. It is also used as nematicides and soil pests. Fenoxycarb- It has a carbamate group but acts as a juvenile hormone mimic and it is a carbamate insect growth regulator. (An insect growth regulator (IGR) is a substance (chemical) that inhibits the life cycle of an insect). Aldicarb- The trade name of Aldicarb is Temik. It is effective against thrips, aphids, spider mites, flea, hoppers, and leaf miners, but is primarily used as Nematicides. Aldicarb is a cholinesterase inhibitor which prevents the breakdown of acetylcholine in the synapse. 37
Thiodicarb- (Larvin) it is very effective against lepidopteran pests. It exhibits combined ovicidal, larvicidal, adulticidal and residual activity. It is a stomach poison provides the best solution for the control of gregarious polyphagous leaf feeders like Spodoptera spp. Other examples of carbamates such as Mythomyl, Oxamyl, benomyl etc. f) Synthetic pyrethroids - These are extracted from Chrysanthemum flowers. These are the mixtures of six esters named Pyrethrins I and II, cinerin I and II and jasmolin I and II. Generally it is botanical insecticides but as they contain only one of these esters, insect species tend to develop resistance to them. Generally pyrethroids shows low mammalian toxicity but pyrethrum, are highly toxic to fish and bees because they having all six esters properties hence it is not suited in agriculture. These are contact and stomach poisons. Cypermethrine is a synthetic pyrethroids used as an insecticide in large-scale commercial agricultural applications as well as in consumer products for domestic purposes. It behaves as a fast-acting neurotoxin in insects. Examples - Cypermethrine (Demon EC, Demon WP), Permethrin (Dragnet (Permethrin Pro), Permethrin Dust, Tick Repellent), Deltamethrin (Delta Dust, Delta Gard, Suspend SC), Bifenthrin (Talstar Granules, Talstar Concentrate), Cyfluthrin (Temp SC, Tempo WP), Allethrin, Resmethrin, Fenvalerate etc. Ant chalk contains the pesticides Deltamethrin and Cypermethrine. g) Fumigant: These are the substance which produces gas, vapour, fumes or smoke intended to kill insects, nematodes, bacteria or rodents. Generally these are solid, liquid or gaseous substances which contain halogen atoms. They are used to disinfect the buildings, stored produce or the soil. Common fumigants used to treat stored products or nursery stock includes Carbon disulphide, hydrogen cyanide, naphthalene, nicotine, and methyl bromide, Ethylene dibromide, and phosphine. Soil fumigants commonly used as Nematicides are methyl bromide, dichloropropane, propylene oxide, dibromochloropropane, and chloropicrin. Chloropicrin is called as “tear gas”. Fumigation is a method of pest control that completely fills an area with gaseous pesticides or fumigants to suffocate or poison the pests within. Fumigation with formaldehyde solution and potassium permanganate is banned. Vikane® gas (Sulfuryl fluoride) fumigant is scientifically proven to be 100% effective against all stages of bed bug. h) Nematicides-A nematicide is a type of chemical pesticide used to kill plant- parasitic nematodes. Nematicides have tended to be broad-spectrum toxicants possessing high volatility or other properties promoting migration through the soil. Aldicarb (Temik), a carbamate insecticide marketed by Bayer Crop Science, is an example of a commonly used commercial nematicide it has been used for control of soil-borne nematodes. Aldicarb is a cholinesterase inhibitor, which prevents the breakdown of acetylcholine in the synapse. E.g. Avermectins nematicides (abamectin), Botanical nematicides (carvacrol), Carbamate nematicides (benomyl. Carbofuran. Carbosulfan, Aldicarb), 38
fumigant nematicides (carbon disulfide, cyanogen, Methyl bromide), organophosphorus nematicides (Phosphamidon, Phorate). i) Rodenticides- A poison used to kill rodents. In rats the chemicals reacts with the hydrochloric acids present in the stomach and release phosphine gas which is lethal to the rats. E.g. Zinc-phosphide, Aluminium phosphide, Warfarin, Bromadiolone (anticoagulant type).Zinc phosphide is typically added to rodent baits in a concentration of 0.75% to 2.0%. j) Novel insecticides/New groups of insecticides/Newer Insecticides: - 1. Neonicotinoids - These are new class of insecticides with novel mode of action. It is effective against sucking pests. It acts on the nicotine acetylcholine receptors (nAChR) at the synaptic junctions of insect central nervous system. Examples - Imidacloprid, Acetamiprid, Thiomethoxam, Thiocloprid, Clothianidin etc. Imidacloprid - The trade name is Confidor (Bayer), Gaucha (Bayer), Admire etc. It is effective as a seed dressing Gaucha (Bayer) and foliar application Confidor (Bayer) against sucking pests like Aphid, Jassids, Thrips and White fly. Acetamiprid - The trade name is Pride, Dhanprit, Manik, Lift, Polar, mudra, Record, Enova. It is broad spectrum insecticides effective against sucking pests. Thiomethoxam- The trade name is Cruiser (Syngenta), Actara (Syngenta). It is broad spectrum insecticides effective against sucking pests as a seed treatment Cruiser (Syngenta) and foliar spray Actara (Syngenta). Thiocloprid - The trade name is Alanto, Calypso. It is broad spectrum insecticides effective against the insect pests. It acts as a stomach poison. 2. Spinosyns - Spinosad - It is introduced by Dow-Elango in 1994. It is derived from new species of Actinomycetes, Saccharo polyspora spinose. It is commercially available as Spinosad (Tracer). It acts as stomach and contact poison. Spinosad is a mixture of Spinosyns A and D. It is broad spectrum insecticides effective against caterpillars. It acts on the nicotine acetylcholine receptors (nAChR) at the synaptic junctions of insect central nervous system. 3. Avermectins - These are generally best for the control of greenhouse pests and insects like leaf miners, spider and mites. It possess novel mode of action by acting on GABA (Gamma Amino Butyric Acid) regulated chloride channels of central nervous system in insects. They are derived from Streptomyces avermitilis by Merck & Co. Abamectin - The trade name is Vertimec. It is a mixture of two analogs i.e. 80% Avermectins B1a and 20% B1b. It acts as a systemic action. 39
Emamectin Benzoate - The trade name is Proclaim, Derim, Safari, and Tatkal. It is analog of abamectin. It is effective against caterpillars. It acts as a both stomach and contact poison. 4. Oxadiazines - Indoxacarb -Commercially available as an Avaunt. It is sodium channel blockers in nervous system. They have a novel mode of action and it is effective against those pests which developed resistance against synthetic pyrethroids. 5. Phenyl pyrazoles - Fipronil -Commercially available as an Icon and Regent. It is effective against those pests that are already become resistance to pyrethroids, organophosphates and carbamates. It possess novel mode of action by acting on GABA regulated chloride channels of central nervous system in insects. It is stomach and contact poison with systemic action. It can use as a foliar, seed treatment and soil application for controlling pests. 6. Diamides -These are the Ryanodine receptors modulators. A large Ca++ release channel in the membrane of muscle sarcoplasmic reticulum (SR) is called the ryanodine receptor, because of sensitivity to inhibition by a plant alkaloid ryanodine. Ryanodine - It is neutral alkaloid isolated from the stem, roots, leaves and stalks of plant Ryania speciosa. It is contact as well as stomach poison. Flubendiamide- First synthetic ryanodine receptor insecticide to be commercialized. Commercially available as Fame (Bayer) in Suspension Concentrate (SC) formulation and Takumi (TATA) in Granule formulation. It is effective against lepidopteran pests. It is safe to bees and other natural enemies. Rynaxypyr (Chlorantraniliprole) -Commercially available as Coragen (DuPont). It is effective against lepidopteran pests. It is available in Suspension Concentrate (SC) formulation. Rynaxypyr controls insect pest by activating insect ryanodine receptors. Cyazypyr (Cyantraniliprole) - Commercially available as Benevia (DuPont). It is available in Oil Dispersion (OD) formulation. It is effective against lepidopteran pests and also sucking pests. It also shows ovicidal and larvicidal effect. It also harmful to bees and other natural enemies. 7. Cartap Hydrochloride -It is Nereis toxin analog means animal originated insecticides. It is extracted form a marine annelids, Lumbriconereis heteropoda. It is contact, stomach and systemic poison. It is effective against chewing and sucking pests. Commercially available as Caldan, Padan, Campas. It is available in the formulation of Soluble Powder (SP). 8. New Pyrethroids -Examples - Lambda-cyhalothrin (Karate, Matador, Riva), Bifenthrin. The mode of action is same as that of synthetic pyrethroids. They have broad spectrum activity against white fly, mites and cotton bollworm. Lambda-cyhalothrin is also used for control of mosquitoes and thrips. 40
9. New Acaricides / Miticides - Fenazaquin -Commercially available as a Magister. It is contact poison. It is a Mitochondrial Electron Transport Inhibitor. It is environmentally safe. Propergit -Commercially available as an Omite, Proguard, Indomite. It is stomach poison and fumigants action. Spiromesifen -Commercially available as an Oberon. It is lipid biosynthesis inhibitor. It is available in Suspension Concentrate (SC). 10. Insect Growth Regulators (IGR’s) -Insect Growth Regulators (IGRs) are compounds which interfere with the growth, development and metamorphosis of insects. It acts on the endocrine system of insects. It is environmentally safe. IGRs prevent an insect from reaching maturity by interfering with the molting processor inhibiting the juvenile hormone. Death typically occurs within 3 to 10 days, depending on the IGR product, the insect's life stage at the time the product is applied, and how quickly the insect develops. It affects the immature stages of insects, preventing them from maturity, No adulticidal effect. IGRs are typically used as insecticides to control populations of harmful insect pests such as cockroaches and fleas. IGRs include synthetic analogues of insect hormones such as ecdysoids and juvenoids (JH Mimics), non-hormonal compounds such as Anti JH and chitin synthesis inhibitors.
Types if IGR’s : -
a) Juvenile Hormones Mimics (JH Mimics)/Juvenoids - JH mimics were first identified by Williams and Slama in the year 1966. They found that the paper towel kept in a glass jar used for rearing a Pyrrhocoris bug caused the bug to die before reaching adult stage. They named the factor from the paper as ‘paper factor’ or ‘juvabione’. They found that the paper was manufactured from the wood pulp of balsam fir tree (Abies balsamea) which contained the JH mimic. JH Mimics have anti-metamorphic effect on immature stages of insect. JH Mimics are larvicidal and ovicidal in action and they disrupt diapause and inhibit embryogenesis in insects. Methoprene, Fenoxycarb, Novaluron Pyriproxyfen (Nylar) are used as Juvenile Hormones Mimics. Fenoxycarb has been used for fire ant management. It sterilized the queen of colony. Pyriproxyfen used for suppressing the pest like flies, mosquitoes. Methoprene is approved by the WHO for use in drinking water to control mosquito larvae. It is also used to control of larva of hornfly, stored tobacco pests (cigarette beetle or tobacco beetle), green house homopterans, red ants, leaf mining flies of vegetables and flowers.
b) Chitin synthesis inhibitors - It is also called as IDI (Insect Development Inhibitors). It works by preventing the formation of chitin, a carbohydrate needed to form the insect's 41
exoskeleton. Benzoyl phenyl urease has been found to have the ability of inhibiting chitin synthesis in vivo by blocking the activity of the enzyme chitin synthetase. It prevents the acetylation of glucose to form glucosamine which is one of the components of the insect exoskeleton. E.g. Lufenuron (PROGRAM) and Flufenoxuron. Two important compounds in this category are Diflubenzuron (Dimilin) and Penfluron. Another compound from the class is thiadizines; buprofezin has been effective against hemipteran insects like white fly. It inhibits the biosynthesis of chitin. Chitin synthesis inhibitors have been registered for use in many countries and used successfully against pests of soybean, cotton, apple, fruits, vegetables, forest trees and mosquitoes and pests of stored grain.
Advantages of IGRs- Effective in minute quantities and so are economical. Target specific and so safe to natural enemies. Bio-degradable, non-persistent and non-polluting. Non-toxic to humans, animals and plants.
Disadvantages of IGRs- Kills only certain stages of pest. Slow mode of action. Since they are chemicals possibility of build-up of resistance. Unstable in the environment.
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THE INSECTICIDES ACT, 1968 The insecticides act was passed by the parliament of India in 1968. There were 38 sections of this act in which the sections 4, 7, 8 & 36 were enforced from 1/3/1971 and remaining from 1/8/1971. An act to regulate the import, manufactures, sale, transport, distribution and use of insecticides with a view to prevent risk to human beings on animals and for matters connected therewith. The Insecticide act was designed to implement the recommendation of the Kerala and Madras Food Poisoning cases Inquiry Commission, which inquired to several death from insecticide contaminated food in April and May-1958.
Salient features of the Insecticides Act Compulsory registration of the product at the Central level and licenses for manufacture, formulation and sale at state level. Inter – departmental / ministerial / organizational co-ordination is achieved by a high level advisory board “Central Insecticides Board” with 24 members (to be raised to 29 by an amendment) drawn from various fields having expert knowledge of the subject. “Registration Committee” to look after the registration aspects of all Insecticides. Establishment of enforcement machinery like Insecticide Analysts and Insecticide Inspectors by the Central or State Government. Establishment of Central Laboratory Power to prohibit the import, manufactures and sale of pesticides and also confiscates the stocks. The offences are punishable and size and other penalties are prescribed. Both the Central and State Governments are empowered to make rules prescribe forms and fees.
The Central Insecticides Board (CIB) - Established under the section 4 of Insecticide Act-1968. The Central Insecticides Board advices on matters relating to: The risk to human beings or animals involved in the use of insecticides and the safety measures necessary to prevent such risk. The manufacture, sale, storage, transport, distribution of insecticides with a view to ensure safety to human beings and animals. Board members (29); The Director General Health Services (Chairman), The Drugs Controller, India The Plant Protection Adviser to the Government of India, The Director General, ICAR The Director General, ICMR Totally 24 members – others from various other fields such as BIS, Animal husbandry, Pharmacology, Fisheries, Wild life etc.
The Registration Committee (RC) - Established under the section 5 of Insecticide Act-1968. It comprises a Chairman and five members. Among them are: Deputy Director General, Crop Sciences, ICAR-Chairman, Drugs Controller, India, Plant Protection Adviser to the Government of India. Role of RC- To register insecticides after scrutinizing them with regard to efficacy and safety. Registration of Insecticides - When applied for registration, the RC allots registration number within a period of 12 months. When pesticide registered for first time in India, provisional registration for two years given initially. After data generation full registration allowed. 43
The Central Insecticides Laboratory (CIL): - It carries out the analysis relating to insecticide registration and other matters. Insecticide Inspectors: - Central or State Government appoints person called Insecticide Inspector who is empowered; to enter and search premises, to stop the distribution or sale or use of insecticide, take samples of insecticide and send for analysis. The Insecticides Rules, 1971- There are nine chapters in the insecticide rule, It has 46 rules.1971 relating to the functions of CIB, RC, CIL, grant of licenses, packing, labelling, first aid, antidote protective clothing etc. Major Pesticide Control Legislations in India Sr. Legislation Regulatory Body No. 1 Insecticide Act, 1968 & Ministry of Agriculture Department of Insecticide Rule, 1971 Agriculture & Cooperation. 2 Environment Protection Act, 1986 Ministry of Environment & Forestry 3 Prevention of Food Adulteration Ministry of Health & Family Welfare. Act, 1954
Insecticide residues and waiting period: - Residues- The toxicant that remains in the environment (like soil, water, plant harvested produce, etc.) after the application of insecticides. Persistence- The duration of retention of pesticides is called persistence. Waiting period- is the minimum period allowed between time of application of pesticide and harvest of commodities. MRL (Maximum Residue Limits): - It is the maximum amount of pesticide residue that is expected to remain on food products when a pesticide is used according to label directions that will not be a concern to human health. Acceptable daily intake or ADI: - It is a measure of the amount of a specific substance in food or drinking water that can be ingested (orally) on a daily basis over a lifetime without an appreciable health risk. Expressed in milligrams (of the substance) per kilograms of body weight per day MRL is calculated by the formula; MRL=ADI x W/MDI x 100 x SF MRL- Maximum Residue Limits, ADI- Acceptable Daily Intake, W-Waiting period MDI- Maximum Daily Intake, SF-Safety factor.
TOXICITY OF INSECTICIDES Toxicology: Toxicology is the science which deals with study of the poisons and their effect on living organisms. Toxin/Poison: A substance which produces harmful effect when ingested /inhaled/absorbed by the human being. Poison is a substances which when taken orally in quantities even less than 4 gm or inhaled in concentrations less than 200 parts per million (ppm) in air quickly fatal, by means other than physical or mechanical. Toxicity: Toxicity is the inherent ability of a pesticide to cause harm to a specific organism. 44
Types of toxicity: Acute Toxicity - It is result of single dose, which causes death of insects and Chronic Toxicity - It is result of cumulative effect of several small doses, each dose not produces symptoms of death.
Degree of toxicity/Toxicity parameters -
LD50 (Median lethal dose): LD50 defined as the amount of insecticide per unit weight which will kill 50% of the test organism / insect.LD50 usually expressed as mg/kg body weight or g/larva or adult insect.
LC50 (Median lethal concentration): LC50 defined as the percentage of toxicant required to kill 50% of the given organism or insect. This is used when the exact
dose per insect is not known, but the concentration is known.LC50 is expressed in PPM (1/1,000,000) or Percentage (1/100).
LT50 (Median lethal time):LT50 is defined as the total time required to kill50% of the insect population at a certain dose or concentration.LT50 expressed in hours or minutes.LT50is used in field studies and also for testing insect viruses (NPV).
KD50: Median knockdown dose Dose of insecticide or time required to KT50: Median knockdown time knockdown 50% of the insects.
KD50 and KT50 are used for evaluating synthetic pyrethroids against insects.
ED50: Median effective dose These terms are used to express the
EC50: Median effective concentration effectiveness of Insect Growth Regulators. ED50 and EC50 are defined as the dose or concentration of the chemical (IGR) required to affect 50% of population and produce desired symptoms in them.
Based on their LD50 values pesticides can be classified are as follows; Categorizations of Pesticides
Depiction
Colour of Bright Red Bright Yellow Bright Blue Bright Green triangle Toxicity Extremely Toxic Highly Toxic Moderately Toxic Slightly Toxic Class LD50 01 to 50 mg/kg 51-500 mg/kg 501-5000 mg/kg >5000 mg/kg value (mg/kg) Signal POISON POISON DANGER CAUTION Words Warning Keep out of reach Keep out of reach Keep out of reach ------words of children. of children. of children. Examples Phorate, Phosphamidon, Dimethoate, Mosquito Monocrotophos, quinalphos, Malathion, repellant oils and zinc phosphide, Carbaryl liquids, and most ethyl mercury other household acetate, insecticides.
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FORMULATIONS OF INSECTICIDES Definition: - Incorporation of pesticide into a suitable carrier, solvent and the supplementary agents or adjuvant is known as formulation. It is mixture of active ingredients (a.i.) i.e. the actual amount of toxicants in the product mixture that controls the pest and inert ingredients such as water, emulsifiers, solvents, dry carrier material, stabilizers, dye, and surfactants: spreaders, stickers, wetting agents. Why Add Inert Ingredients?- For ease of pesticide product handling, Inert make measuring and mixing, pesticides easier, To provide for safety, Makes the active ingredients work better. Necessity of formulation - Pure pesticide is costly; the formulations give cheaper & safe form of insecticide. High concentrations may prove to be phototoxic. Easy distribution on large area due to large volume formulation. Pure material is highly hazardous in handling, formulation decreases the residual hazards. To improve effectiveness of insecticides. Types of Formulations Liquid formulation Dry Formulation Emulsifiable Concentrate (EC) e.g. Chlorpyriphos Dustable Powder (DP) E.g. Lindane 0.65%, 20 EC, Profenophos 50 EC Malathion5%, Carbaryl 10%. Soluble Liquid/Concentrate (SL)- e.g. Wettable Powder (WP) E.g. Carbaryl 50% WP. Monocrotophos 36 SL.Imidacloprid 17.8SL Fumigants - e.g. Aluminium phosphide, Ethylene Soluble Powder (SP) E.g. Acephate75 SP. dibromide, ED/CT mixture Aerosol (Aer) e.g. Aerosol bomb Granule (GR) E.g. Phorate 10%, Carbofuran 3%, Quinalphos 5%. Oil Dispersion (OD)E.g. Cyantraniliprole Water Dispersible Granule (WG) E.g. Thiomethoxam 25 WG Suspension Concentrate (SC)-E.g. Flubendiamide Baits Solution (S) Pellets Ultra-Low Volume Liquid (ULV) Micro emulsion (ME) Concentrate Emulsion (EW) Capsule suspensions (CS)
A) Dry Formulation:- 1. Dusts: In this formulation the toxicant is diluted either by mixing with or by impregnation on carrier. The carrier may be an organic flour (Walnut shell flour, wood bark) or pulverized mineral (Sulphur, Lime, Gypsum, talc) or clay (attapulgite, bentonites, kaolin).The toxicant in a dust formulation ranges from 065% to 25%.Those having particle size less than 100 micron. Dust formulation must be done in a calm weather and early in the morning when plant is wet with dew. It is denoted by ‘D’ E.g. Lindane 0.65%, Malathion5%, Carbaryl 10%. 46
Advantages: Dust can be used where water supply is difficult & inadequate. Less quantity required as compared to spray material. Application is faster than spray solution. Due to the light in weight it can be used in hilly areas or muddy fields. It is cheaper and requires less cost. Disadvantages: Drift problems - dust are likely to blow away along with wind velocity. Due to the less deposition on plants its efficiency is decreases. 2. Wettable powders/Water dispersal powders: WP is the powdered formulation which gives stable suspension when diluted with water. The toxicant/active ingredient in a formulation ranges from 15% to 95%.It is formulated by blending the toxicant with diluents such as attapulgite, a surface active agents and auxiliary material such as sodium salt & sticker is also added. It is more effective than dust. High active ingredient is present. It is denoted by ‘WP/WDP’ E.g. Carbaryl 50% WP. 3. Granules: It is a granular formulation of insecticide composed of inert material (Carrier, diluents like vermiculite) or vegetable carrier impregnated or fused with toxicant. The particle size ranges from 250 to 1250 microns. The formulation contains 2 to 10% concentration of toxicant. This formulation is used for the control of weeds, plant diseases and insect-pests, nematodes, snails & slugs, rodents. It is denoted by ‘G’. E.g. Phorate 10%, Carbofuran 3%, Quinalphos 5%. Advantages: No undue loss of insecticide. Undesirable contamination is prevented. Water is not requiring for application. Less harmful to natural enemies Disadvantages: Not as effective as spray. Scorching may occur if toxicant in concentrated. 4. Soluble Powder (SP) - Similar to the Wettable powder, but dissolves readily and forms a true solution. It composed of pesticides, water soluble diluents, Wetting and dispersing agents. High active ingredient is present i.e. 15-95% by weight. E.g. Acephate75 SP. 5. Water Dispersible Granule (WG) - It composed of active ingredients, diluents, Wetting and dispersing agents. E.g. Thiomethoxam 25 WG. 6. Bait- A bait is an example of a dry or liquid product that is applied without mixing.
B) Liquid formulation- 1. Emulsifiable Concentrate: The formulation contains the toxicant, a solvent of toxicant and an emulsifying agent. Active ingredient dissolved in a petroleum-based solvent with an emulsifier added. It is clear solution which gives an emulsion of oil-in water type when diluted with water to spray. When sprayed the solvent evaporates quickly leaving a deposits of toxicant from which water also evaporated. Emulsifying agents used are alkaline soap, organic amines, carbohydrates, gum, lipids, proteins etc. High active ingredient is present. It is denoted by ‘EC’. E.g. Chlorpyriphos 20 EC, Profenophos 50 EC. Advantages: Dilution of chemical with water is possible, Easy to handle, little agitation, Leaves little residue, Better contact with insect cuticle, Surface tension of the spray reduced, Even distribution of insecticides possible. Disadvantages: Phytotoxic – plant injury, easily absorbed by the skin, Flammable, 2. Solution: (SL) - Toxicants dissolved in organic solvent such as Amyl acetate, Carbon tetrachloride, Ethylene dichloride, Xylene, Petroleum & Kerosene. It is mostly used to 47
control household pests & aquatic insects like mosquitoes. It is denoted by ‘SL’. E.g. Imidacloprid 17.8SL. 3. Ultra-Low Volume Liquid (ULV) - Special-purpose formulation, Almost 100% active ingredient, Agriculture, forestry, mosquito control. 4. Aerosol: The toxicant is suspended in mixture particles (Size ranges from 0.1 to 50 microns) in air as a fog or mist. This is achieved by; i) burning the toxicant with heat, ii) the toxicant dissolved in liquefied gas. When released the toxicant particles to float in air with the rapid evaporation of the released gas. Effective against flying insects and the pests in dense foliage. Some are ready-to-use, little active ingredient, High drift potential, some require highly specialized equipment, Respiratory protection needed. E.g. Aerosol bomb. 5. Fumigants: -A chemical compound which is volatile at ordinary temperature & sufficiently toxic is known as fumigants. It is used against stored grain pest & nematodes. E.g. Aluminium phosphide tablets, Ethylene dibromide, ED/CT Mixtures. Adjuvants: Supplementary agents which do not contribute directly to the toxic effect of pesticide but are used for improving physical condition of pesticides so that pesticide become more effective in action. Types of Adjuvants- Dust carriers - Organic flour, lime, gypsum, talc, kaolin, & volcanic ash. Solvents - Amyl acetate, Carbon tetrachloride, Ethylene dichloride, Xylene, Petroleum & Kerosene, pin oil. Dispersing agents - Polyfon H, Blancol, and Daxad 21. Emulsifiers (Emulsifying agents) - It is surface active agents. The principal function is to modify the properties. They may be O/W (oil in water type) or W/O (water in oil type).The pesticidal emulsions are oil in water type. E.g. Alkaline soaps, Carbohydrates, proteins, organic amines. Wetting and spreading agents - Soaps, Teepol, Tergitos, and Triton X-100. Spreader-stickers; - These are adjuvants added to the spray mix, intended to help coverage of the product on the plant material and to slow chemical residue loss. The spreader component is a surfactant that reduces the surface tension of water. This allows the product to spread across the leaf more uniformly and allows the active ingredient to be better absorbed by the plant. The sticker component increases the adhesion of spray drops to the leaf and slows loss of the chemical by rain. . Terminology- 1. Suspension: Solid particles suspended in a liquid like hot chocolate. 2. Emulsion: One liquid dispersed within another liquid like water with milk and Paint. 3. Synergists: Chemicals which by themselves are nontoxic or only slightly toxic but when mixed with pesticides increase their toxicity. E.g. Sesamin, Sulphoxide. 4. Antagonistic: The chemicals when mixed together reduce the toxicity of mixture.
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APPLICATION TECHNIQUES OF SPRAY FLUIDS Pesticide Application Methods: - The desired effect of a pesticide can be obtained only if it is applied by an appropriate method in appropriate time. The method of application depends on nature of pesticide, formulation, pests to be managed, site of application, availability of water etc.
1. Dusting: Dusting is carried out in the morning hours and during very light air stream. It can be done manually or by using dusters. Sometimes dust can be applied in soil for the control of soil insects. Dusting is cheaper and suited for dry land crop pest control. 2. Spraying: Spraying is normally carried out by mixing EC (or) WP formulations in water. There are three types of spraying. Types of spraying Spray fluid Droplet size Area covered Equipment used (lit/acre) (Micron) per day High volume spraying 200-400 150 2.5 acre Knapsack, Rocker sprayers Low volume spraying 40-60 70-150 5.6 acre Power sprayer, Mist blower Ultra-Low volume 2-4lit 20-70 20 acre ULV sprayer, spraying Electrodyn sprayer
3. Granular application: Highly toxic pesticides are handled safely in the form of granules. Granules can be applied directly on the soil or in the plant parts. The methods of application are, Broadcasting: Granules are mixed with equal quantity of sand and broadcasted directly on the soil or in thin film of standing water. E.g. Carbofuran 3G applied @ 1.45 kg/seed in rice nursery in a thin film of water and impound water for 3 days.
In furrow application: Granules are applied at the time of sowing in furrows in beds and covered with soil before irrigation. (e.g.) Carbofuran 3G applied @ 3 g per meter row for the control of sorghum shoot fly.
Side dressing: After the establishment of the plants, the granules are applied a little away from the plant (10-15 cm) in a furrow.
Spot application: Granules are applied @ 5 cm away and 5 cm deep on the sides of plant. This reduces the quantity of insecticide required.
Ring application: Granules are applied in a ring form around the trees.
Root zone application: Granules are encapsulated and placed in the root zone of the plant. E.g. Carbofuran in rice.
Leaf whorl application : Granules are applied by mixing it with equal quantity of sand in the central whorl of crops like sorghum, maize, sugarcane to control internal borer.
Pralinage: The surface of banana sucker intended for planting is trimmed. The sucker is dipped in wet clay slurry and Carbofuran 3G is sprinkled (20 40 g/sucker) to control burrowing nematode. 49
4. Seed pelleting/seed dressing: The insecticide mixed with seed before sowing e.g. sorghum seeds are treated with Chlorpyriphos 4 ml/kg in 20 ml of water and shade dried to control shoot fly. The Carbofuran 50 SP is directly used as dry seed dressing insecticide against sorghum shoot fly. 5. Seedling root dip : It is followed to control early stage pests e.g. in rice to control sucking pests and stem borer in early transplanted crop, a shallow pit lined with polythene sheet is prepared in the field. To this 0.5 kg urea in 2.5 liter of water and 100 ml Chlorpyriphos in 2.5 liter of water prepared separately are poured. The solution is made up to 50 ml with water and the roots of seedlings in bundles are dipped for 20 min before transplanting. 6. Sett treatment: Treat the sugarcane setts in 0.05% Malathion for 15 minutes to protect them from scales. Treat the sugarcane setts in 0.05% Imidacloprid 70 WS @ 175 g/ha or 7 g/l dipped for 16 minutes to protect them from termites. 7. Trunk/stem injection: This method is used for the control of coconut pests like black headed caterpillar, mite etc. Drill a downward slanting hole of 1.25 cm diameter to a depth of 5 cm at a light of about 1.5 m above ground level and inject 5 ml of monocrotophos 36 WSC into the stem and plug the hole with cement (or) clay mixed with fungicide. Pseudo stem injection of banana, an injecting gun or hypodermic syringe is used for the control of banana aphid, vector of bunchy top disease. 8. Padding: Stem borers of mango, silk cotton and cashew can be controlled by this method. Bark of infested tree (5 x 5 cm) is removed on three sides leaving bottom as a flap. Small quantity of absorbent cotton is placed in the exposed area and 5-10 ml of Monocrotophos 36 WSP is added using ink filler. Close the flap and cover with clay mixed with fungicide. 9. Swabbing : Coffee white borer is controlled by swabbing the trunk and branches with HCH (BHC) 1 per cent suspension. 10. Root feeding: Trunk injection in coconut results in wounding of trees and root feeding is an alternate and safe chemical method to control black headed caterpillar, eriophyid mite, and red palm weevil. Monocrotophos 10 ml and equal quantity of water are taken in a polythene bag and cut the end (slant cut at 45) of a growing root tip (dull white root) is placed inside the insecticide solution and the bag is tied with root. The insecticide absorbed by root, enter the plant system and control the insect. 11. Soil drenching: Soil drenching is the process of adding diluted chemicals directly to the base of the plants to provide targeted, deep penetration. Most often used with insecticides to control certain subterranean pests. E.g. Soil drenching of two formulations of Imidacloprid (Confidor 200 SL & admire 70 WG) for the management of mealybugs on grapes in Maharashtra, INDIA. 12. Capsule placement: The systemic poison could be applied in capsules to get toxic effect for a long period. E.g. In banana to control bunchy top vector (aphid) the insecticide is filled in gelatin capsules and placed in the crown region. 13. Baiting: The toxicant is mixed with a bait material so as to attract the insects towards the toxicant. 50
Spodoptera: Bait prepared with 0.5 kg molasses, 0.5 kg Carbaryl 50 WP and 5 kg of rice bran with required water (3 liters) is made into small pellets and dropped in the field in the evening hours. Rats: Zinc phosphide is mixed at 1:49 ratio with food like popped rice or maize or cholam or coconut pieces (or) warfarin can be mixed at 1:19 ratio with food. Ready to use cake formulation (Bromadiolone) is also available. Coconut rhinoceros beetle: Castor rotten cake 5 kg is mixed with insecticide. 14. Fumigation: Fumigants are available in solid and liquid forms. They can be applied in the following way. Soil: To control the nematode in soil, the liquid fumigants are injected by using injecting gun. Storage: Liquid fumigants like Ethylene dibromide (EDB), Methyl bromide (MB), carbon tetrachloride etc. and solid fumigant like Aluminium phosphide are recommended in godowns to control stored product pest. Trunk: Aluminium phosphide is inserted into the affected portion of coconut tree and plugged with cement or mud for the control of red palm weevil.
PHYTOTOXICITY AND COMPATIBILITY OF INSECTICIDES Phytotoxicity: - Phytotoxic means harmful or lethal to plant. Phytotoxicity is the degree to which a chemical or other compound is toxic to plants. Compatibility: - Cox (1941) coined the term compatibility. In pest control treatment, two or more pesticides, fungicides or even fertilizers are sprayed or applied in the same operation to minimize cost of labour. Before mixing two different chemicals, their physical and chemical properties should be well understood. Incompatible pesticides should not be mixed. Only compatible pesticides can be mixed when two or more ingredients a successful sprays or dust mixture they are said to be complete. Incompatibility of pesticides may be of following types, Chemical incompatibility- Chemical compounds in the two pesticides react with another producing a different compound, reducing the pesticidal activity of the pesticides (Degradation of active ingredient). Biological incompatibility (Phytotoxic incompatibility)-The mixed product exhibit phytotoxic action, which independently is not phytotoxic. Physical incompatibility-The physical form of the pesticides change, and one of them become unstable or hazardous for application. Gray (1914) worked on pesticides combination and also he divided the mixtures of insecticides and fungicides into 5 classes designated by letters A-I, A, B, C and D.
Insecticides mixtures: -Recently combination of insecticides are recommended to control insect pest which are resistant to major pesticides that are used commonly because these insecticides mixtures are usually prepared which have different modes of action i.e. organophosphates or carbamates with synthetic pyrethroids so that the development of resistance to these combinations is extremely rare but they are not prepared by combining organophosphates and carbamates which have same mode of action. 51
Sr. No. Insecticides 1 Chlorpyriphos 50% EC + Cypermethrine 5% EC 2 Profenophos 40% EC + Cypermethrine 5% EC 3 Chlorpyriphos 16% EC + Alphamethrin 1% EC 4 Deltamethrin 1% EC + Triazophos 35% EC 5 Ethion 40% EC + Chlorpyriphos 5% EC
First aid: In cane of suspected poisoning; call on the physician immediately. Before calling on a doctor, first aid treatments can be done by any person. Swallowed poison -During vomiting, head should be faced downwards. Stomach content should be removed within 4 h of poisoning. To give a soothing effect, give either egg mixed with water, gelatin, butter, cream, milk, mashed potato. In case of nicotine poisoning, give coffee or strong tea. Skin contamination -Contaminated clothes should be removed. Thoroughly wash with soap and water. Inhaled poison -Person should be moved to a ventilated place after loosing the tight cloths. Avoid applying frequent pressure on the chest. Antidotes:-The substances that are used to cure the cases of insecticidal poisoning are known as antidotes. There are two types of antidotes; 1. Universal Antidotes - It contains 2 parts of activated charcoal + 1 part of magnesium oxide + 1 part of tannic acid + ½ glass of warm water. It is useful for acids and heavy metal poisoning. 2. Specific Antidotes - Which varies with toxicant as follows;
Sr. Antidote/Medicine Used in poisoning due to No. 1 Common salt (Sodium chloride) 2 Activated charcoal (7g)/Magnesium oxide (3.5g)/Tannic acid (3.5g) in warm water. Stomach poison in general 3 Sodium thio-sulphate 4 Calcium gluconate Chlorinated insecticide, Carbon tetrachloride, ethylene dichloride, Mercurial compound 5 Phenobarbital (or) Pentobarbital Stomach poison of chlorinated hydrocarbon insecticides 6 Sodium bicarbonate Stomach poison of organophosphate compounds 7 Atropine sulphate (2-4mg) or PAM Organophosphate Compounds (Pyridine-Z aldoxime-N-methliodide) 8 Atropine sulphate (2-4mg ) Carbamates 9 Phenobarbital Synthetic pyrethroids 10 Potassium permanganate Nicotine, Zinc phosphide 11 Vitamin K1 and K2 Warfarin, Zinc phosphide 12 epinephrine Methyl bromide 13 Methyl nitrite ampule Cyanides
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RECENT /NEWER METHODS OF PEST CONTROL Biorational Control: - Controlling insects using chemicals that affect insect behavior, growth or reproduction, is called biorational control. Biorational pesticides: - Pest control materials that are relatively non-toxic to people with few environmental side-effects are sometimes called biorational pesticides.
Sr. No. Biorational Method/ Newer Method of Pest Control 1 Insect Growth Regulator 2 Chitin synthesis inhibitor 3 JH analogues, Anti JH 4 Moulting hormone 5 Allelochemicals and Pheromones 6 Attractant 7 Repellent 8 Antifeedants/Feeding deterrents 9 Chemosterilants 10 Sterile male release technique/Sterility technique 11 Genetic control (Transgenic crops) 12 Gamma radiation
1) Insect Attractant- Chemicals that cause insects to make oriented movements towards their source are called insect attractants. They influence both gustatory (taste) and olfactory (smell) receptors. The interspecific Semio-chemicals that favor the producer are called Allomones. While those favors the receiver called as Kairomones. Types of Attractants: a) Pheromones: Pheromones are chemicals secreted into the external environment by an animal which elicit a specific reaction in a receiving individual of the same species. Sex pheromones – A sex pheromones released by one sex only to attract the other sex of the species. E.g. For cotton bollworm- Vitlure & Ervitlure for spotted bollworm, Helilure & Hexalure for American bollworm. Aggregation pheromones – The pheromones released by one sex only give response in both sexes of a species. E.g. Melon fruit fly attracted by cue-lure. b) Food lures: Chemical present in plants that attract insect for feeding. They stimulate olfactory receptors. List of Natural and Synthetic Food Lures Insect-Pests Natural and synthetic food lures Natural Pests of cruciferous Iso-thiocyanates from seeds of cruciferous Onion fly Propyl mercaptan from onions Bark beetle Terpenes from barks Housefly /Moths/Butterflies fermenting syrup, Sugar and molasses Synthetic Oriental fruit fly Methyl eugenol Mediterranean fruit fly Cue lure Melon fruit fly TriMed lure DBM (Diamond Back Moth) Sinigrin 53
c) Ovipositional lures: - Chemicals that govern the selection of suitable sites for oviposition by adult female. E.g. Paramethyl-acetophenon = Rice stem borer, Helicoverpa lay eggs more on plants which dipped in juice of corn silk. 2) Repellents- Chemicals that induce avoiding (oriented) movements in insects away from their source are called repellents. They prevent insect damage to plants or animals by rendering them unattractive, unpalatable or offensive. Types of repellents a) Physical repellents: Produce repellence by physical means. Contact stimuli repellents: Substances like wax or oil when applied on leaf surface changes physical texture of leaf which are disagreeable to insects Auditory repellents: Amplified sound is helpful in repelling mosquitoes. Barrier repellents: Tar bands on trees and mosquito nets are examples. Visual repellents: Yellow light acts as visual repellents to some insects. Feeding repellents: Antifeedants are feeding repellents. They inhibit feeding. b) Chemical repellents: Repellents of Plant origin Essentials oils of Citronella, Camphor and cedar wood act as repellents. Commercial mosquito repellent ‘Odomos’ uses citronella oil extracted from lemongrass, Andrpogon pardus as repellent. Pyrethrum extracted form Chrysanthemum is a good repellent. Creosol and coal-tar oil protect wood form termite attacks. Synthetic repellents Insects Repellents 1 Mosquito, blood suckers Dimethyl phthalate 2 Mites (chiggers) Benzyl benzoate 3 Crawling insects Trichloro-benzene 4 Phytophagous insects Bordeaux mixture 5 Wood feeders Pentachlorophenol 6 Fabric eaters Naphthalene or mothballs 7 Bees Smoke
3) Antifeedants/Feeding deterrents- Antifeedants are chemicals that inhibit feeding in insects when applied on the foliage (food) without impairing their appetite and gustatory receptors or driving (repelling) them away from the food. They are also called gustatory repellents, feeding deterrents and rejectants. Since do not feed on treated surface they die due to starvation. Groups of antifeedants- Triazenes: AC 24055 has been the most widely used Triazenes which is a oduorless, tasteless, non-toxic chemical which inhibit feeding in chewing insects like caterpillars, cockroaches and beetles. Organotins: They are compounds containing tin. Triphenyl tin acetate is an important antifeedants in this group effective against cotton leaf worm, Colorado potato beetle, caterpillars and grass hoppers. 54
Carbamates: At substance lethal doses thiocarbamates and phenyl carbamates act as antifeedants of leaf feeding insects like caterpillars and Colorado potato beetle. Baygon is a systemic antifeedants against cotton boll weevil. Botanicals: Antifeedants from non-host plants of the pest can be used for their control the following antifeedants are produced from plants. Pyrethrum: Extracted from flowers of Chrysanthemum cinerarifolium acts as antifeedants at low doses against biting fly, Glossina sp. Neem: Extracted from leaves and fruits of neem (Azadirachta indica) is an antifeedants against many chewing pests and desert locust in particular. Apple factor: Phlorizin is extracted from apple which is effective against non- apple feeding aphids. Solanum alkaloids: Leptine, tomatine and solanine are alkaloids extracted from Solanum plants and are antifeedants to leaf hoppers. Miscellaneous compounds: Compounds like copper stearate, copper resinate, mercuric chloride and Phosphon are good antifeedants. 4) Sterility technique- Control of pest population achieved by releasing large number of sterilized male insects, which will compete with the normal males and reduce the insect population in subsequent generation. It is usually referred as SIT (Sterile insect technique) or SIRM (Sterile insect release method). Sterile insect release method is a genetic control method. It is also called autocidal control since insects are used against members of their own species. E.F. Knippling in 1937 in South East USA used the SIRM technique to control the screw worm fly a serious livestock pest. It is also referred as ‘Father of Male Sterility Technique’. The sterile to fertile male ratio, called S: F ratio is important, as the reduction in reproductive potential of natural population depends on S: F ratio. The mating with the sterile males will produce sterile eggs. SIRM technique can also be used after insecticide application which will be more effective. Methods of sterilization- a) Chemosterilants: Any chemical which interfere with the reproductive capacity of an insect. They inhibit nucleic acid synthesis, inhibit gonad development, and produce mutagenic effect which prevents the production of F1 generation. E.g. TEPA (Tetra ethylene pent amine), Metapa, thiotepa, apholate, Chloro ethylamine, 5-Fluororacil, Amithopterin. 0.5% TEPA reduced housefly population. Apholate solution cause male sterility in boll weevil. b) Irradiation: Irradiation done by exposing insects to radiations, x rays and neutrons of these, radiation by Cobalt 60 is the most common method. 55
Limitations- Not effective against insects which are prolific breeders. Sterilizing and mutagenic effect of Chemosterilants and irradiation cause problem in higher animals and man (Carcinogenic and mutagenic). 5) Genetic control (Transgenic crops) - Use of molecular biology techniques for the management of insect pests. The following are some strategies. a) Wide hybridization: This technique involves transfer of genes from one species to other by conventional breeding. The genes for resistance are transferred from a different species. E.g. WBPH resistant gene has been transferred to Oryza sativa from O. officinalis. b) Somaclonal variability: The variation observed in tissue culture derived progeny. E.g. Somaclonal variants of sorghum resistant to Spodoptera litura have been evolved. c) Transgenic plants: Transgenic plants are plants which possess one or more additional genes. This is achieved by cloning additional genes into the plant genome by genetic engineering techniques. The added genes impart resistance to pests. Transgenic plants have been produced by addition of one or more following gene Bt. endotoxin from Bacillus thuringiensis, Protease inhibitors, Amylase inhibitors, Lectins and Enzymes. Bt. Endotoxin gene: The gram positive bacteria Bacillus thuringiensis produces a crystal toxin called (delta) endotoxin. The endotoxin is a stomach poison and kills the lepidopteran insects if consumed. The gene (DNA fragment) responsible for producing endotoxin is isolated from Bt. and cloned into plants like cotton, potato, maize, etc. to produce Transgenic cotton, etc. Transgenic Bt plants Target insect pests 1 Cotton Bollworms, S. litura 2 Maize European corn borer 3 Rice Leaf folder, stem borer 4 Tobacco, Tomato Cut worms 5 Potato, Eggplant Colorado potato beetle
6. Semio-Chemicals The word “Semion” means “Signal”. Chemicals involved in the communication are termed as a Semio-chemical. Semio-chemicals are chemical substances that mediate communication between organisms. Most secreted by exocrine glands in insects. Can be divided into two groups based on who `sends’ a massage and who `received’. Semio-chemicals may be classified into Pheromones (intraspecific Semio-chemicals) and Allelochemicals (interspecific Semio-chemicals). Intraspecific Semio-chemicals: - These are responsible for behavioral changes among individuals of the species. E.g. Pheromones. Interspecific Semio-chemicals: - These are responsible for behavioral changes between the individuals of different species. E.g. Allelochemicals. Pheromone- (Pherein = to carry, Hormone = to excite) - A substance that is secreted by an organism to the outside environment and cause specific reaction in a receiving 56 organism of the same species. In 1959, German chemists Karlson and Luscher coined the term pheromone. Pheromones are exocrine secretions of insects which are used for communication among different individuals of the species (Karlson and Luscher, 1959). Pheromones can be classified into 2 groups- a) Primer pheromones: Primer initiates changes in development, such as maturation. They act through gustatory (taste) sensilla. e. g. Caste determination and reproduction in social insects like ants, bees, wasps, and termites are mediated by primer pheromones. These pheromones are not of much practical value in IPM. b) Releaser pheromones: Releaser which induce immediate behavioural change. This pheromones act through olfactory (smell) sensilla and directly act on the central nervous system of the recipient and modify their behavior. They can be successfully used in pest management programme. Releaser pheromones may be further subdivided into; Sex pheromones, Aggregation pheromones, Alarm pheromones, Trail pheromones. Sex pheromones- o A substance generally produces by a female to attract the male for the purpose of mating. o In 1959, A. A. Butenandt isolated and identified the first pheromone, a sex attractant from silkworm moths, Bombykol. o They are most commonly released by females but may be released by males also. o Insects order producing the sex pheromones- Lepidoptera, Orthoptera, Dictyoptera, Diptera, Coleoptera, Hymenoptera, Hemiptera, Neuroptera and Mecoptera. o In Lepidoptera, sex pheromone system is highly evolved. o Pheromone producing glands: In Lepidoptera they are produced by eversible glands at the tip of the abdomen of the females. Aphrodisiac glands of male insects are present as scent brushes at the tip of the abdomen. E.g. Male butterfly. Androconia is glandular scales on wings of male moths producing aphrodisiacs. Aphrodisiacs are substances that aid in courtship of the insects after the two sexes are brought together. In many cases males produce aphrodisiacs. o Pheromone reception: Female sex pheromones are usually received by olfactory sensilla on male antennae. In pheromone perceiving insects, the antennae of male moths are larger and greatly branched than female moths to accommodate numerous olfactory sensilla. o Chemical nature of sex pheromones: In general pheromones have a large number of carbon atoms and high molecular weight. It is a primary alcohol. It is in slow release dispensers (rubber septa hollow fibers) that are used as lures in traps of various designs.
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The following are some of the female sex pheromones identified in insects Sr. Name of the Insect Pheromone No. 1 Silkworm, Bombyx mori Bombykol 2 Gypsy moth, Porthesia dispar Gyplure, disparlure 3 Pink bollworm ,Pectinophora gossypiella Pectinolure, Gossyplure 4 Cabbage looper, Trichoplusia ni Looplure 5 Tobacco cutworm, Spodoptera litura Spodolure 6 Gram pod borer, Helicoverpa armigera Helilure 7 Honey bee queen, Apis sp. Queen’s substance 8 Spotted/Spiny bollworm Earis vitella Erilure 9 Diamond Back Moth DBM Lure 10 Brinjal shoot & fruit borer Leucinolure Examples of male sex pheromones- Cotton boll weevil (Grandlure), Cabbage looper, Mediterranean fruit fly. Aggregation pheromones- A substance produces by the one or both sexes that bring both sexes together for feeding and reproduction. These are released by members of one sex only but elicit responses in members of both sexes of a species. E. g. Bark and ambrosia beetles generally found in Coleoptera & Dictyoptera order Alarm pheromones- A substance produce by an insect to repel and disperse other insects in the areas. These pheromones are reported in Homoptera, Isoptera and Hymenoptera. E. g. Poison glands in ants, Cephalic glands in termites, Sting and mandibular glands of workers bees and cornicles in aphids. An individual also release them when an enemy attacks. Trail pheromones- Trail marking pheromones are substance of low persistence that are released and perceived by individuals in trail. These pheromones are specially found in social insects like hymenopterans and termites. The ants (Formic rufa) use formic acids as a trail marker. They facilitate migration of colony to new site in search of food. Uses of pheromones- Monitoring, Mass trapping, mating disruption etc. Allelochemicals- R. H. Whittaker coined the term Allelochemicals in 1970. It is defined as non-nutrient substance originating from an organism (Plants & Animals), which affect the behavior condition or ecological welfare of organisms of another species. Allelochemicals affects the behavior, growth and development of an insect as well as their natural enemies. Allelochemicals are divided in following sub-categories. Allomones Kairomones Synomones Apneumones Allomones - A chemical substances produce by organisms that favorable to the emitter but not to receiver e.g. Venom secreted by social wasps 58
Kairomones- A chemical substances produce by organisms that favorable to the receiver but not to emitter. Synomones- A chemical substances produce by organisms that favorable to the both receiver and emitter. Apneumones- A chemical substances produce by non-living material that favorable to the receiving organisms but detrimental to an organisms of another species that is found on or in non-living material.
Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Course No. : ENTO-121 Course Title: FUNDAMENTALS OF ENTOMOLOGY
Course Credit: 1+1=2 Teaching Schedule (Theory):
Lecture No. Name of Topic
1 & 2 Introduction * Introduction and history of Entomology including contribution of scientist in brief (Aristotal, Carlous Linnaeus, Fabricious, Charles Darwin, Lefroy, Wigglesworth, Snodgrass, Pradhan, Runwal., Pruthi and Ananthkrishnan. Definition : Insect & Entomology Characteristics of Class - Insecta * Economic importance of insects : harmful, beneficial and productive insects * Pests of national importance e.g. Locust, termite and white grub along with their extent of losses. * Premier Institutes concerned with Entomology : International – CAB (UK), IOBC(Trinidad), International Institute of Insect Physiology – Kenya. National – National Institute of Biological Control (Bangalore) NCIPM - (New Delhi), CIB (Faridabad), National Plant Protection Institute, Hyderabad, Indian Grain Storage Institute (Hapur), 3 Dominance of Class Insecta 4 Insect Integument Structure, chemical composition and functions of Cuticle Process of moulting, cuticular appendages and processes 5 Body segmentation and structure of Head Body regions, structure of head capsule, and positions of head and structure of cervix 6 Structure of thorax and abdomen Segmentation, appendages and processes, pregenital & post genital appendages and structure of genitalia 7 Structure and modifications of Antennae Components of typical antenna, basal articulation, functions and modifications (with examples) 8 & 9 Structure and modifications of mouth parts Structure and feeding mechanism of Mandibulate type of mouthparts and Haustellate type of mouth parts (piercing & sucking ; chewing & lapping; sponging; rasping & sucking and siphoning) 10 Structure and modifications of leg Components of typical leg, basal articulation, tripod locomotion and modifications (with examples) 11 Structure and modifications of wings Basal articulation, regions, hypothetical wing venation, wing coupling apparatus and modifications (with examples)
1 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
12 Sensory and Sound producing organs Sensory organs : Location and function (mechanoreceptors, audio receptors chemo receptors, thermo & humidity receptors, photoreceptors and vision & visual organs, with examples Sound producing organs : Tympanum & Stridulatory organs 13 Metamorphosis and Seasonal adoptions Definition and types of metamorphosis with examples. Seasonal adoptions (aestivation, quiescence, hibernation and diapauses) with examples 14 & 15 Immature stages of Insects Structure of egg, eclosion and its type (with examples) Types of larvae and pupae (with examples); nymphal stage 16 Structure and functions of Digestive system Alimentary canal: salivary glands, proventriculus, filter chamber, digestion and absorption of food. 17 Structure and functions of Circulatory system Organs of circulations, composition of blood and functioning of dorsal vessel 18 Structure and functions of excretory system Organs of excretion and their functioning; products of excretion 19 Structure and functions of Respiratory system Organs of respiration and types of respiration (with examples) 20 & 21 Structure and functions of Nervous system Organs of nervous system, types of neurons and conduction of nerve impulse 22 & 23 Structure of Reproductive systems in Insects Male and female reproductive systems and types of reproduction 24 & 25 Systematics: Importance and history of Taxonomy; development of binomial nomenclature along with its rules and regulations Definitions : Order, Family, Genus, Species, Sub-species and Biotypes 26 & 27 Classification Phylum Arthropoda along with its characters Class Insecta along with its characters 28 & 29 Characters of orders along with families of agricultural importance Orthoptera (Family: Acrididae), Dictyoptera (Family: Mantidae) 30 & 31 Characters of orders along with families of agricultural importance Odonata, Isoptera (Family: Termitidae) and Thysanoptera (Family:Thripidae) 32 Characters of orders along with families of agricultural importance Hemiptera (Family: Pentatomidae, Coreidae, Pyrrhocoridae, Lygaeidae, Cicadellidae, Delphacidae, Aphididae, Aleurodidae, Coccidae, Psedococcidae 33 Characters of orders along with families of agricultural importance Neuroptera (Family: Chrysopidae), Lepidoptera (Family: Noctuidae, Sphingidae, Pyralidae, Gelechiidae, Arctiidae. 34 & 35 Characters of orders along with families of agricultural importance Diptera (Family:Cecidomyiidae, Trypetidae, Tachinidae, Agromyziidae) Hymenoptera (Family: Tenthridinidae, Apidae, Trichogrammatidae, Ichneumonidae, Braconidae) 36 Characters of orders along with families of agricultural importance Coleoptera (Family: Coccinellidae, Chrysomelidae, Cerambycidae, Bruchidae, Scarabaeidae, Curculionidae)
2 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
INTRODUCTION
The word Insect derived from the Greek word insecare, means cut in pieces or engraved /segmented. Insects belong to the Phylum Arthropoda(Artho= jointed, Poda= Legs) which is the biggest phylum of kingdomAnimalia. More than three quarters of the animals on earth are arthropods, and most of these are insects. KingdomAnimalia is classified into twelve phyla.
Insect: -The insects are the tracheate arthropods in which the body is divided in to head, thorax and abdomen possessing two pairs of wings and three pairs of legs and single pair of antennae. Entomology: -Greek word-(Entomon = Insect; Logos = Study) It is the branch of zoologyor biological science that deals with the study of insects.
Branches of Entomology:- 1.) Study and use of insects in crime investigations is known as Forensic Entomology. 2.) Study of insects related to live stock and veterinary animals is known as Veterinary Entomology. 3.) Study of insects in relation to Human beings is known as Medical Entomology.
HISTORY OF ENTOMOLOGY
In ancient scripts like Ramayana and Mahabharata, some of the terms used were related to insects. They are; Pipilika – Ant, Pathanga – grasshoppers, Madhumakshika – honey bees, Umbakapalika - termite queen
References of Insects in Ancient Indian Literature
Mahabharta : (1424 – 1366 BC) Mentions about silk, honey and lac The Famous story of “Lakshgruha” i.e. House of Lac build by Kauravas to burn their cousins live, Pandavas. Amarkosha Sanskrit dictionary provide references like Patanga and Bhramar of flies , Moths, beetles and Glow worms Sushruta : Surgeon (100 - 200 AD) : Classified ants (Pipilika), Mosquitoes and Flies Umaswati : Physician (0 - 100 AD) : Classified the Bees
Pests of national importance – E.g. Locust, termite and white grub.
3 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Contribution of scientist: -
Aristotle (384-322 B.C.) – He was the Father of biological classification. First person grouped insects in Mandibulate and Haustellate types and winged and wing less groups. He gave the terms like Coleoptera and Diptera
Carolus Linnaeus (1758) – Father of Taxonomy In his publication “Systema Naturae” 1758 includes 28 Indian insect species.
J. C. Fabricius (1745- 1808) – Danish Entomologist described over 10,000 insect species. Published “Philosophia Entomologia” in 1778. World’s first Text Book in Entomology. The first entomologist who made any extensive study of Indian Insects. Classified the insects in to 13 orders based on type of mouth parts.
J.G. Koenig (1767-1779) – J.G Koenig was the first to collect number of insects from Coromandel and Southern India. For his memory Red cotton bug is named as Dysdercus koenigi
Snodgrass R. E. (1875) – Great Insect Morphologist referred as a Father of Insect Morphology. He wrote book - Principles of InsectMorphology
Lionel de Nicevelle (1901) – Was appointed as the first entomologist to the Government of India.
Maxwell Lefroy (1903) – Was appointed as the second entomologist to the Government of India. First Imperial Entomologist 1906 publication of ‘Indian insect pests’P 1909 publication of Indian insect life’
Mithan Lal Runwal (1908) - Outstanding work on Termites / White ants Contributions to ecology, embryology and Locust study are noteworthy
Sir Vincent B. Wigglesworth– Insect physiologist, work on blood sucking bug, Bed Bug. Father of Insect Physiology
T.B Fletcher (1914) – The first Govt. Entomologist of Madras state. Wrote a book ‘Some South Indian insects’. Second Imperial Entomologist. 4 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
T.V. Rama Krishna Ayyar (1940) – Wrote a book ‘Hand book of Economic Entomology for South India’
H S Pruthi (1963)– 1934 - First Indian, Imperial Entomologist of Independent India 1963 - He become first Plant Protection Advisor to Government of India ‘Wrote a Text book of Agricultural Entomology’
Dr. M.S. Mani's (1968)– Wrote a "General Entomology"
Dr. S. Pradhan(1969) - Wrote a "Insect Pests of Crops" and Father of ModernApplied Entomology in India
B. Vasantharaj David and T.Kumara Swami (1975) – Wrote a‘Elements of Economic Entomology’
M R G K Nair (1975) – Wrote a‘Insects and Mites of crops in India’.
K.K. Nayar, N. Ananthakrishnan and B. Vasantharaj David(1976) – Wrote a‘General and applied Entomology’
1912- Plant Quarantine Act was enforced. 1914- Destructive Insects and Pests Act was enforced. (DIPA) 1916 - Imperial Forest Research Institute Established at Dehradun (Uttarakhanda) 1925 – Indian Lac Research Institute started at Ranchi, Bihar 1937 - A laboratory for storage pests was started at Hapur, U.P. 1937 -Entomology division was started in IARI, New Delhi 1939 – Locust Warning Organization established 1946- ‘Directorate of Plant Protection, Quarantine and Storage’ of GOI started. 1968- The Govt. of India enacted ‘Central Insecticide Act’ which came into force from 1st January, 1971. Establishment of entomological institutes
IOBC,West Indies(Trinidad)- (International Organization for Biological and Integrated Control of Noxious animals and Plants) ICIPE,Kenya – International Centre of Insect Physiology and Ecology NCIPM,New Delhi - (National Centre for Integrated Pest Management - 1988) PDBC, Bangalore - (Project Directorate of Biological Control -1993), and thenPDBC are (NBAII) i.e. National Bureau of Agriculturally Important Insects(2009)&nowareNBAIR -National Bureau of Agricultural Insect Resources. CIB, Faridabad – Central Insecticide Board NPPTI, Hyderabad – National Plant Protection Training Institute - 1966 IGSI, Hapur U.P. - Indian Grain Storage Institute 1946 Directorate of plant protection Quarantine and storage(DPPQS), Faridabad 1937 Establishment of Entomology division at IARI New Delhi CABI, UK – Commonwealth Agricultural Bureau International 5 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
ECONOMIC IMPORTANCE OF INSECTS
The field of entomology may be divided into 2 major aspects.
1. Fundamental Entomology or General Entomology 2. Applied Entomology or Economic Entomology
Fundamental Entomology:-
It deals with the basic or academic aspects of the Science of Entomology. It includes morphology, anatomy, physiology and taxonomy of the insects. In this case we study the subject for gaining knowledge on Entomology irrespective of whether it is useful or harmful.
Applied Entomology or Economic Entomology:- It deals with the usefulness of the Science of Entomology for the benefit of mankind. Applied entomology covers the study of insects which are either beneficial or harmful to human beings. It deals with the ways in which beneficial insects like predators, parasitoids, pollinators or productive insects like honey bees, silkworm and lac insect can be best exploited for our welfare. Applied entomology also studies the methods in which harmful insects or pests can be managed without causing significant damage or loss to us.
Economic classification of insects
Insects can be classified as follows based on their economic importance.
1. Insects of no economic importance:-
There are many insects found in forests, and agricultural lands which neither cause harm nor benefit us.
2. Insects of economic importance:- A. Injurious insects a) Pests of cultivated plants (crop pests) Each cultivated plant damage by many insect pests which feed on them reduces the yield of the crop. E.g. cotton bollworm, Rice stem bores. b) Storage pests Insects feed on stored products and cause economic loss. E.g. Rice weevil, Pulse beetle. c) Pest attacking cattle and domestic animals Cattle are affected by pests like Horse fly, Flesh fly, Fleas and Lice. They suck blood and sometimes eat the flash. d) House hold and disease carrying insects House hold pests include cockroach, ants, etc. Disease carrying insects are like mosquitoes, houseflies, bed bugs, fleas etc.
6 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
B. Beneficial insects
I) Productive insects i) Silk worm: - The silk worm filament secreted from the salivary gland of the larva helps us in producing silk. ii) Honey bee: - Provides us with honey and many other byproducts like bees wax and royal jelly. iii) Lac insects: - The secretion from the body of these scale insects is called lac. Useful in making vanishes and polishes. iv) Insects useful as drugs, food, ornaments etc., (a)As medicine e.g. Sting of honey bees- remedy for rheumatism and arthritis Eanthoridin - extracted from blister beetle –useful as hair tonic.
(b)As food - for animals and human being. For animals- aquatic insects used as fish food. Grasshoppers, termites, pupae of moths. They have been used as food by human beings in different parts of the world. (c) Ornaments, entertainers -Artists and designers copy colour of butterflies. - Beetles worm as necklace. - Insect collection is a hobby. (d)Scientific research Drosophila and mosquitoes are useful in genetic and toxicological studies respectively.
(II) Helpful insects (i) Parasites: These are small insects which feed and live on harmful insects by completing their life cycle in a host and kill the host insect. E.g. egg, larval and pupal parasitoids (ii) Predators: These are large insects which capture and devour harmful insects.E.g. Coccinellids and Preying Mantid. (iii)Pollinators: Many cross pollinated plants depend on insects for pollination and fruit set. E.g. Honey bees, aid in pollination of sunflower crop. (iv)Weed killers: Insects which feed on weeds kill them thereby killers. E.g. Mexican beetle eats on Parthenium (Gajar gavat). Cochineal insect feeds in Opuntia dillenii. (v) Soil builders: soil insects such as ants, beetles, larval of cutworms, crickets, collombola, make tunnels in soil and facilitate aeration in soil. They become good manure after death and enrich soil. (vi) Scavengers: Insects which feed on dead and decaying matter are called scavengers.They important for maintaining hygiene in the surroundings.E.g. Carrion beetles, Rove beetles feed on dead animals and plants. d) House hold and disease carrying insects i) Pests which cause damage to belongings of human being like furniture, wool, paper etc. E.g. Cockroaches, furniture beetle, sliver fish etc. ii) Pests which cause painful bite, inject venoms. E.g. Wasps, bees sting us. Hairy caterpillar nettling hairs are poisonous. Mosquitoes, bugs bite, piece and suck blood from us. iii) Disease causing Mosquito- Malaria, Filariasis, dengue fever. Housefly- Typhoid, Cholera, Leprosy, Anthrax.
7 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
INSECT DOMINANCE
Measures of dominance: 1. More number of species. 2. Large number of individuals in a single species: e.g. Locust swarm comprising 9 of 10 numbers of individuals, occupying large area. 3. Great variety of habitats 4. Long geological history
Reasons for dominance: There are several structural, morphological and physiological factors responsible for insect dominance. They are: 1. Capacity for flight 2. More adaptability or universality smaller size: Majority of insects are small in their size conferring the following physiological and ecological advantages. 3. Presence of exoskeleton: Insect body is covered with an outer cuticle called exoskeleton which is made up of a cuticular protein called Chitin. This is light in weight and gives strength, rigidity and flexibility to the insect body. 4. Resistance to desiccation: Insects minimize the water loss from their body surface through prevention of water loss (wax layer of epicuticle, closable spiracles, egg shell) conservation of water (capable of utilizing metabolic water, reabsorption of water from fecal matter, use less quantity of water to remove the nitrogenous waste) 5. Tracheal system of respiration: This ensures direct transfer of adequate oxygen to actively breathing tissues. Spiracles through their closing mechanism admit air and restrict water loss. 6. Higher reproductive potential: Reproductive potential of insect is high e.g. Egg laying capacity (fecundity) of queen termite is 6000 - 7000 eggs per day for 15 long years. Short development period e.g., Corn aphid produces 16 nymphs per female which reaches the adulthood within 16 days. Presence of special types of reproduction other than oviparity and viviparity like Polyembryony, Parthenogenesis and Paedogenesis. 7. Presence of complete metamorphosis: More than 82 per cent of insects undergo complete metamorphosis (holometabolous insects) with four stages. As the larval and adult food sources are different, competition for food is less. 8. Presence of defense mechanisms: By different defense mechanisms, insects escape from the enemies to increase their survival rate. 9. Hexapod locomotion: Insects uses 3 legs at a time during locomotion, while the remaining 3 legs are static, which gives greater stability.
8 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
INSECT INTEGUMENT
The vertebrates have internal skeleton known as endoskeletonwhile in insects it is located outside the body forming exoskeleton. Insect cuticle provides space for attachment of muscles of antenna and mouthparts, called as tentorium. Insect body wall iscalled as Integument or Exoskeleton. It is the external covering of the body which is ectodermal in origin. It is rigid, flexible, lighter, stronger and variously modified in different body parts to suit different modes of life. Integument consists of 3 layers:- 1) Cuticle (Upper) 2) Epidermis (or) hypodermis(Middle) 3) basement membrane (Inner)
1. Cuticle:-
It is outermost thick layer of integument secreted by epidermis. It is non-cellular. It is divided in to two regions:-Epicuticle (Upper) and Procuticle(Inner)
A. Epicuticle:
It is a thin outermost layer varying in thickness from 1-4μ. Chitin is absent in epicuticle.It consists of the following 4 layers
9 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Cement layer:It is secreted by dermal glands and is composed of lipoprotein.It protects the body from external damage. Wax layer: Itconsisting of long chain hydrocarbons, esters of fatty acids and alcohols. It serves as water proof layer preventing water loss from the body Polyphenol layer: It is a non-static layer containing various types of phenols which are mainly used in the formation of the proteins.It is resistant to acids and organic solvents. Cuticulin layer: It is an amber coloured thin layer over the surface of the epidermis which is strengthened by outer polyphenol layer.It serves the purpose of permeability and also acts as growth barrier.
B. Procuticle:
It is differentiated in to exo and endocuticle. Exocuticle: It is darkly pigmented, hard and sclerotized. This layer is made up of chitin and sclerotin. Endocuticle: It is soft, light coloured and unsclerotized. This layer is made up of chitin and arthropodin.
Pore canals: These are numerous fine vertical channels traversing both exo and endocuticle. Pore canals present in the exocuticle helps in the deposition of epicuticle. They are useful in transportation of cuticular material and enzymes to the outer pro and epicuticle parts.
Composition of cuticle: ♣ Two major components of insect cuticle are; i) Chitin,ii) Proteins. i) Chitin:
It is a nitrogenous polysaccharide. It consists of high molecular weight polymer of anhydro-N-acetyl glucosamine residues joined by β-glycosidic linkages.It is water insoluble but soluble in dilute acids, alkalies and organic solvents. ii) Proteins:Cuticle has 3 types of proteins
Arthropodin:An untanned protein means it is soft water soluble protein present in endocuticle. The conversion of arthopodin in to sclerotin is known as sclerotization or tanning. Sclerotin:It is also called tanned protein which is amber coloured and present only in exocuticle.This is water insoluble. Resilin:It is a rubber like elastic protein which is colourless and present in joints such as wing hinge ligaments, leg joints, clypeolabral joints or suture and tergosternal joints.
10 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
2. Epidermis (or) hypodermis:
It is an inner unicellular layer resting on basement membrane with the following function. i. Cuticle secretion ii. Digestion and absorption of old cuticle iii. Wound repairing iv. Gives surface look Adjacent epidermal cells are held together by means of certain cytoplasmic processes which are known as desmosomes. All the epidermal cells are glandular and secrete cuticle and the enzymes involved in production and digestion of old cuticle during moulting. The epidermal cells get differentiated in to following types based on the function they perform and may modify in to; a)Dermal glands producing cement layer b)Trichogen cell producing hair like seta or trichome. c)Moulting glands secreting moulting fluid which digests the old cuticle d)Peristigmatic glands around the spiracles in case of Dipteran larvae
3. Basement membrane:
It is the basal part of the body wall formed from degenerated epidermal cells and appears as non-living amorphous (shapeless) granular layer of integument. It is about 0.5µ in thickness and consists of fibrous protein, glycosaminoglycans which are polymers of disaccharides. The basement membrane forms a continuous sheet beneath the epidermis, where muscles are attached and become continuous with sarcolemma of the muscles.
Functions of Insect Integument
o It provides protection to the internal organs enclosed by it. o It gives shape and size to the insects. o It provides surface for the attachment of muscles. o It conserves moisture and prevents desiccation. o It prevents entry of pathogens and insecticides. o It forms sense organ. o It contains pigments to make insects attractive.
11 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
CUTICULAR/ INTEGUMENTAL MODIFICATIONS:
Cuticular modification
Cuticular Cuticular out growths invagination
Cuticular Setae Apodemes appendages Spurs
Apophyses Cuticular Aculei
processes Spines A. Cuticular out growths:
They are divided into cuticular appendages and cuticular processes depending on the presence or absence of membranous articulations.
I. Cuticular appendages:
These are the outgrowths of the cuticle / integument connected with it by means of a membranous joint. They arise from modified epidermal cells. These are classified in to setae and spurs.
(1) Seta/ Macrotrichia:
♣ Commonly known as hairs and arise from a cup like alveolus or pit. Setae are hollow structures developed as extension of exocuticle and are produced by a single enlarged hypodermal cell called ‘ trichogen’ cell. Articular membrane is usually produced by a second hypodermal cell called ‘tormogen’ cell. ♣ Setae have role of taxonomic importance and vary with species to species. Study of arrangement of setae is known as ‘chaetotaxy’. (2) Spurs: ♣ Occur on the legs of many insects and differ from setae in beingmulticellular in origin. II. Cuticular processes: They have no membranous articulation; They are of two types (1) Microtrichia / fixed hairs / aculei: ♣ These are minute hair like structures found on wings of Mecoptera and certain Diptera. (2) Spines: ♣ Outgrowths of the cuticle which are more or less thorn like in form. 12 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Sr. Spurs Spines No. 1 Cuticular appendages Cuticular processes 2 Movable, multicellular structures and thick These are immovable outgrowths of cuticle walled 3 E.g.: present on tibia of plant hoppers and honey E.g.: hind tibia of grasshopper and leaf bees hoppers B. Cuticular invagination: The body wall or cuticle of the body wall invaginate internally and grow in to definite structures which are of two types. ♠ Apodemes- Hollow cuticular invaginations whichprovide area for muscle attachment ♠ Apophyses- Solid invaginations of the cuticle which gives mechanical support to various organs by forming distinct skeletal structures. MOULTING PROCESS
Process of periodical shedding of old cuticle and formation of new cuticle this process is known as moulting. Itis a complex process which involves: - Apolysis, Ecdysis and Sclerotization. Apolysis : [Apo = formation ; Lysis = dissolution] The dissolution of old cuticle and formation of new one is known as apolysis. It starts with repeated mitotic division of epidermal cells resulting in increase in number and size of epidermis, Because of this change, the epidermal cells exert tension on cuticular surface and as a result get separated them from the cuticle. Due to separation of epidermis from the cuticle a sub cuticular space is created and the epidermal cells starts producing their secretion i.e. moulting fluid and cuticular material into this space. Ecdysis : The stage where the insect has both newly formed epi and procuticle. The ecdysial membrane starts splitting along the line of weakness due to muscular activity of the inner developing insect and also because of swallowing of air & water resulting in the distention of the gut and also due to the pumping of blood from abdomen to thorax through muscular activity. After the breakage of old cuticles, the new instar comes out bringing its head followed by thorax, abdomen and appendages. Sclerotization : After shedding of old cuticle the new cuticle which is soft, milky white coloured becomes dark and hard through the process known as tanning (or) sclerotization. . Three types of hormones involved in the process of moulting which are as follows- JH: Juvenile Hormone: Produced from corpora allata of brain that helps the insects to be in immature stage. MH: Moulting hormone: Produced from prothoracic glands of brain that induces the process of moulting. Eclosion Hormone: Released from neurosecretory cells in the brain that help in the process of ecdysis or eclosion.
13 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
BODY SEGMENTATION OF INSECT Cockroach, Periplanata americana is a typical insect as it possesses all important characters of class insect. In general, insect body is divided in to a series of rings or segments are known as “somites” or “metameres”. During the process ofevolution, these somites get fused with each other in different ways forming the body parts of the existing arthropods. The type of arrangement of these body segments in embryonic stage is known as primary segmentation while in adult insects is known as the secondary segmentation. Insect body is divided in to three regions or tagmata namely head, thorax and abdomen. This grouping of body segments in to regions is known as tagmosis. Head consists of 6 segmentspossessesmouthparts, compound eyes, simple eyes (ocelli) and a pair of antennae. Thorax consists of 3 segments i.e. prothorax, mesothorax and metathorax, Meso and metathorax are together known as pterothorax. All the three thoracic segments possess a pair of legs and meso and meta thorax possess one pair of wings. Abdomen has 11 segments with genital appendages on 8th and 9th segments. The insect body generally consists of 20 segments.
Fig. General Organization of Insect Body
14 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
INSECT HEAD
It is the foremost part in insect body consisting of 6 segments that are fused to form a head capsule. The head segments can be divided in to two regions i.e. procephalon and gnathocephalon (mouth). Head is attached or articulated to the thorax through neck or cervix. Head capsule is sclerotized and the head capsule excluding appendages formed by the fusion of several sclerites is known as cranium. Inside the head, an endoskeletal structure called the tentoriumwhich give supports to the brain, and provides a rigid origin for muscles of the mandibles and other mouthparts. Head is concerned with feeding and sensory perception.
Segment Appendages I Pre antennary segment Procephalon Pair of compound eyes& three ocelli (Simple eyes)
II Antennary segment Pair of Antennae III Intercalary segment Single labrum IV Mandibular segment Gnathocephalon Pair of Mandibles V Maxillary segment Pair of Maxillae VI Labialsegment Single Labium
Types of head position:
The orientation of head with respect to the rest of the body varies. According to the position or projection of mouth parts the head of the insect can be classified as;
(a) Hypognathous (Hypo – Below: Gnathous – Jaw )
The head remain vertical and is at right angle to the long axis of the body and mouth parts are ventrally placed and projected downwards. This is also kwown as Orthopteroid type.
Eg: Grass hopper, Cockroach.
15 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
CockroachGrass hopper
(b) Prognathous : (Pro – infront: Gnathous – Jaw )
The head remains in the same axis to body and mouth parts are projected forward. This is also known as Coleopteroid type.Eg: beetles
Beetles
(c) Opisthognathous : (Opistho – behind: Gnathous Jaw )
It is same as prognathous but mouthparts are directed backward and held inbetween the fore legs. .This is also kwown as Hemipteroid or Opisthorhynchous type.Eg: bugs
16 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Mosquito Red cotton bug
SCLERITES AND SUTURES OF HEAD
The head capsule is formed by the union of number of sclerites or cuticular plates or areas which are joined together by means of cuticular lines or ridges known as sutures or any of the large or small sclerotized/harden areas of the body wall.
These sutures provide mechanical support to the cranial wall.
Suture: The sclerites separated from each other by means of thin impressed line called suture.(Sometimes referred as a sulcus).
General insect possess the following sclerites-
1. Labrum:It is small sclerite that forms the upper lip of the mouth cavity. It isfreely attached clypeus by means of clypolabral suture.
2.Clypeus:It is situated above the labrum, separated by fronto-clypeal suture & also separated from gena by clypogenal suture.
3.Frons: It is unpaired, facial part of the head capsule lying between the arms of epicranial suture.
4. Gena: It is the area extending from below the compound eyes to just above the mandibles. It is separated from frons by frontoganal suture and from clypeus clypogenal suture.
5. Epicraniun: It forms the upper part of the head extending from frons to the neck.
17 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
6. Vertex: It is the top portion of epicranium which lies behind the frons or the area between the two compound eyes.
7. Epicranial Suture: Starting from the dorsal portion of the epicranium is an inverted Y shape suture known as epicranial suture or ecdysial line. The head capsule breaks open along this line at the time of moulting.
8. Occiput: It is an inverted “U” shaped structure representing the area between the epicranium and post occiput.
9. Post occiput: It is the extreme posterior part of the insect head that remains before the neck region.
10. Occular sclerites: These are cuticular ring like structures present around each compound eye.
11. Antennal sclerites: These form the basis for the antennae and present around the scape.
Anterior view or face view
The common sutures present in head are:
1. Clypeolabral suture:It is the suture present between clypeus and labrum. 2. Clypeofrontal suture or epistomal suture: The suture present betweenclypeus and frons. 3. Epicranial suture: It is an inverted ‘Y’ shaped suture distributed above thefacial region extending up to the epicranial part of the head. It consists of two arms called frontal suture occupying the frons and stem called as coronal suture. This epicranial suture is also known as line of weakness or ecdysial suture because the exuvial membrane splits along this suture during the process of ecdysis. 4. Occipital suture: It is ‘U’ shaped or horseshoe shaped suture between epicranium and occiput.
18 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
5. Post occipital suture: It is the only real suture in insect head. Posterior end of the head is marked by the post occipital suture to which the sclerites are attached. As this suture separates the head from the neck, hence named as real suture. 6. Genal suture: It is the sutures present on the lateral side of the head i.e. gena. 7. Occular suture: It is circular suture present around each compound eye. 8. Antennal suture: It is a marginal depressed ring around the antennal socket.
INSECT THORAX
It is the middle part of the body consisting of 3segmentssuch as prothorax, mesothorax and metathorax, each possessing a pair of legs and a pair of wings on meso and meta thoracic segment. Meso and meta thoracic segments bear a pair of wings each together known as pterothorax (Ptera = wings).
Thorax generally concerned with locomotion.
The body wall of a typical insect is divided into four regions; The dorsal (Upper) region is called dorsum or tergum/notum. |The ventral (Lower) region is called as venter or sternum. The two lateral regions are known as pleurae/pleuron. Sclerites–The cuticle hardens at localized areas form sclerites.
19 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Sutures – The sclerites are separated from each other by means of thin impressesd lines called as sutures. Sclerites forming these regions are called as tergites, sternites and pleurites, respectively.
Sclerites of thoracic segments:- 1. Sclerites of tergum (tergites) - The dorsal sclerites consists of three segmental plates (nota) called pro-notum, meso-notum and meta-notum. Each notum is again divided into three parts i.e pre-scutum, scutum and scutellum. 2. Sclerites of pleuron (pleurites) –it is fully developed in winged insects. It is divided into two parts, anterior episternum and posterior epimeron. It is absent in prothorax. 3. Sclerites of sternum (sternites)–It is divided into eusternum and spinasternum.
INSECT ABDOMEN
The abdomen in the embryo usually consists 11 segments. The abdominal segments are sometimes designated as uromeres. The terminal region of abdomen is called telson which bears anus. The 1st abdominal segment gets fused to metathorax forming propodeum. (In ants, bees and wasps). The first eight abdominal segments carry a pair of spiracles each. Thorax generally concerned with reproduction and metabolic activity.
Appendages of abdomen– 1. Non reproductive appendages – a) Cerci –They are present on 11th segment in most of the insects. It is present inmale cockroach, silverfish, grasshopperCerciusuallyact as tactile organ or sound receptors in grasshopper. They become a part of male genitalia in caddis fly. In earwigs, cerci are modified into defensive organ. b) Prolegs in insect larvae- The larvae of Lepidoptera bear five pairs of abdominal legs called Prolegs on 3rd 4th 5th 6th and 10th segments. These Prolegs bear spines like structures called crochets, on terminal ends to grip the plant surfaces. In case of larvae of sawfly there are eight pairs of Prolegs but are without crochets. c) Abdominal gills- It is present in aquatic insects for respiration. eg. Nymph of odonata. d) Cornicles: Aphids have a pair of short tubes known as cornicles or siphonculi projecting from dorsum of fifth or sixth abdominal segment.
20 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
They permit the escape of waxy fluid which perhaps serves for protection against predators. 2. Reproductive appendages – It includes abdominal Segments from 1 to 7 are pregenital segments, 8th and 9th are known as genital segments as they form genital appendages i.e. ovipositor in females and aedeagus or penis in males. 10thand11thsegments are known as postgenital segments. These organs are specially concern with mating in male and deposition of eggs in females. They are collectively called as external genitalia or gonapophysis. Male external genitalia-The9th sternum bears two styli and pair of claspers which help to hold female during copulation. The aedeagus lies between claspers. Female external genitalia-It has a special egg laying organs called ovipositor for egg lying on 8th and 9th segments.The ovipositor of house fly& fruit fly is called pseudoovipositor.
INSECT ANTENNAE
Antennae are a pair of sensory preoral appendages arising from the 2nd or antennal segment of the head possessing nerves coming from deutocerebrum of the brain. Antennae are also called feelers. They are well developed in adults and poorly developed in immature stages. Antennae are absent in order protura and class Arachnida whereas 2 pairs of antenna (antennules) are present in class Crustacea. Aantennal socket (antennifer) is provided with an antennal suture. The base of socket is connected to the edge of the socket by an articulatory membrane. This permits free movement of antennae
21 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Antenna consists of 3 parts:-
1) Scape: It is the first segment of antenna. It articulates with the head capsule through antennifer which provides movement for the scape.
2) Pedicel: It is the 2nd or middle segment of antenna that forms a joint between scape and flagellum. It consists of the special auditory organ known as “Jhonston’s organ”.
3) Flagellum: It is the last antennal segment which consists of many segments that varies in shape and size.
Types of Insect antennae
SrN Type of antennae Example o. 1 Filiform (Thread like) Grasshopper 2 Setaceous(Whip/ bristle like) Cockroach
3 Moniliform (Like string of beads) Termites& Thrips 4 Pectinate (Comb like) Female mulberry silk moth
5 Bipectinate (Double comb) Male mulberry silk moth
22 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
6 Serrate(Saw like) Pulse beetle, Mango stem borer 7 Clavate (Clubbed) Butterflies, Moths
8 Clavate with hook Skipper butterflies 9 Capitate (Clubbed with knob) Red flour beetle
10 Geniculate (Elbowed) Ants, honey bees, Wasps
11 Lamellate (plate like) Rhinoceros beetles, dung rollers,chaffer beetles
12 Plumose(Feather like) Male Culex mosquito, stylopids
13 Pilose (brush like hairs) Female Culex mosquito
14 Aristate (antennae with arista) House fly 15 Stylate (antennae with style) Jassids, Robber fly
Term Mean
1. Gustatory Related with stimulus of taste
2. Olfactory Related with stimulus of smell
3. Tactile Related with stimulus of touch
23 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Functions of Antennae
1. To feel and find the its way
2. To detect danger
3. To find food
4. To find the opposite sex
5. To communicate with each other e.g. (Ants)
6. To smell – bears olfactory organ e.g. (House fly)
7. To perceive the sound Chorodontonal organe.g. (male mosquito)
8. To serve secondary sexual characters
9. It possesses hydro fuse hairs to form air funnel eg. (Water beetle)
10. Taste hairs occur on antennae e.g. (Cockroach)
11. Helps in mating by holding opposite sex eg. (Flea, Spring tails)
12. Useful for clasping the female during copulation
24 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
STUDY OF INSECTS MOUTH PARTS
Typical mouthpart of an insect consists of the following parts.
(i) Labrum (upper lip)
(ii) A pair of mandibles (upper Jaw)
(iii) A pair of maxillae (lower Jaw)
(iv)Labium (lower lip)
(v) Hypopharynx (tongue)
The mouth parts of insects can be basically grouped in to following types based on the type of food and method of feeding.
Type of Mouth parts
Sr. Type of Mouth parts Examples No. I (Mandibulate type) Those insects feeding on solid food material.
1. Chewing and Biting type Grasshoppers, cockroachesBeetles, Lepidopterous larvae.
II Sucking type / Haustellate type Those insects feeding on liquid food material.
1.Piercing and sucking type Plant Bugs and Mosquitoes
2.Rasping and sucking type Thrips
3.Sponging type Adult Houseflies
4.Chewing and lapping type Honey bees
5.Siphoning type Butterflies and moths
III Other types 1. Mask type Naids of Dragonflies
2. Degenerate type Maggots of Diptera
25 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
MANDIBULATE TYPE OF MOUTH PARTS
Those insects feeding on solid food material such as leaves, fruits, tree bark. I) CHEWING AND BITING TYPE OF MOUTH PARTS E.g. Grass hopper, Cockroach, Beetles, Lepidopterous larvae
(a) Labrum:
It is a single unpaired that forms the upper lip of the mouth cavity. It protects the mandibles and helps in closing of the mouth cavity and guides the food in to mouth or hold the food material while feeding. Labrum hangs down from the clypeus through a clypeo-labral suture. The inner surface of labrum is lined by small lobe like epipharynx, which is the taste organ.
(b) Mandibles:
These are the paired, unsegmented, and strongest and sclerotized structures calledfirst pair of jaws. They are attached to the head capsule by means of two joints known as ginglymus and condyle. They possess teeth like molars and incisors that help in the process of cutting the food material. Each mandible is moved by powerful Abductor and adductor muscles.
26 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
(c) Maxillae:
These are paired and also known as second pair of jaws. These are homologous structures with basal triangular ‘cardo’, middle rectangular ‘stipes’ and the lateral ‘palpifer’ bearing maxillary palpi and lobe like inner ‘lacinia’ and outer ‘galea’. Maxillary palps possess olfactory and gustatory sense receptors and function as sensory organs. These Galea and lacinia helps in holding the food material along with the mandibles.
(d) Labium:
It is known as lower lip and is also called as second maxillae. It closes the mouth cavity from below. It is divided in to proximal prementum. centralmentum and distal submentumPrementum has three terminal lobes. Near the base of pre mentum, on either side lobe like ‘palpiger’ is present which bears labial palps. The median pair is ‘glossae’ and outer ‘paraglossae’ together called ligula that function mainly as gustatory sense organs.
(e) Hypopharynx:
It is a tongue like structure situated between labrum and labium and ducts of salivary glands open on or near its base. The function of hypopharynx is to mix saliva with the food material.
HAUSTELLATE TYPE OF MOUTH PARTS
Those insects feed on liquid food material such plant sap, fruit juice, blood etc 1. PIERCING AND SUCKING TYPEOF MOUTH PARTS
e.g.: plant bugs, mosquitoes They are mainly adopted for piercing the tissues and sucking either plant sap or the nectar or blood from the host.
27 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
a) Labrum : Labrum is modified into a small flap like structure at the base of rostrum. b) Mandibles & maxillae: Mandibles and maxillae are modified in to sharp needle like stylets. (Four in numbers) The mandibular stylets form the outer pair and possess serrated margins at their tip. The maxillary stylets forms the inner pair having smooth curved tips and combining together enclosing a food channel. The food channel is divided in to an upper cibarium and lower salivarium with the help of the grooves present inside the maxillary stylets. Salivarium is used for releasing the saliva and cibarium is used for sucking the sap. c) Labium : Mouth parts are represented by rostrum/beak/Proboscis which is a modification of Labium. It acts as a pouch for protecting the mandibular and maxillary stylets. Rostrum has sensory hairs at its tip for sampling the food and locating spot for piercing. d) Hypopharynx : The hypopharynx is modified in to a pharyngeal pump and is situated at the tip of the food channel.
Feeding Mechanism: At rest proboscis is always held parallel to ventral side of insect body. During feeding the rostrum shot out, stylets released and rostrum looped behind to allow the stylets to penetrate plant tissues. Mandibular stylets by their sliding movement puncture a hole in plant tissues. Then maxillary stylets are pushed inside. Saliva is injected through salivary channel to dilute the cell sap, dissolve the cell wall. Then suck the contents (sap/ blood / nectar) through cibarium with the action of pharyngeal and cibarial muscles.
2. RASPING AND SUCKING TYPE OF MOUTH PARTS E.g. Thrips
Insect like thrips lacerate the epidermis of plant parts and suck the oozing cell sap. These are called asymmetrical type, since right mandible is rudimentary or reduce or absent whereas the left mandible is modified in to a mandibular stylet hence left mandible is present. Maxillae are modified in to maxillary stylets which are mainly useful for sucking the sap that is released outside due to the rasping of tissues by the left mandible.
28 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
3. SPONGING TYPE OF MOUTH PARTS: - e.g.: housefly
a) Labrum: It is represented by labrum epipharynx. It forms stylet. It is born on anterior face of haustellum. b) Mandibles:They are entirely absent. c) Maxillae:They are represented by a pair of maxillary palps.Maxillary palpi are 1-3 segmented d) Labium : These mouthparts are represented by proboscis formed from the labium. The proboscis is divided into a basal rostrum, middle haustellum and adistallabellum. The labellum is a sponge like structure. It is traversed by a number of narrow transverse channels called pseudotrachea which converge at one point in the centre of the labellum. From this point, the food enters in to food channel which is formed by the labrum- epipharynx and hypopharynx. e) Hypopharynx : It is also modified into stylet like structure and is present on haustellum.
Feeding Mechanism: During feeding, the proboscis is pressed over the food material. The pseudo trachea gets filled with the food material by the capillary action which converges at one point in the centre of the labellum. From this point, the food enter in to food channel which is formed by the labrum- epipharynx and hypopharynx and is sucked up from the central point in to the oesophagus.
29 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
4. CHEWING AND LAPPING TYPE OF MOUTH PARTS:e.g.: honey bees
The labrum and mandibles are biting type whereas maxillae, labium and hypopharynx combine together to form a sucking proboscis. a) Labrum:It is narrow plate attached to clypeus. b) Mandibles:The mandibles are dumbbell shaped, used for molding wax and squeezing the nectar. c) Maxillae : Both maxillae are modified and suspended from head. They are articulated through like cardo to which is attached stipes. The maxillary palpi are very small or reduced and it is peg like structure articulating with stipes. The cardo of maxillae unite with submentum of labium forming an inverted “V” shaped lorum. Galea and lacinia attached at the lorum. d) Labium :It is also called as proboscis and consist of following parts; Submentum (lorum),mentum, prementum, labial palp and glossa. Glossae are provided with long hairs and a small spoon shaped lobe, called flabellum or bouton at its apex. Two paraglossa are cup like structure situated at the base of glossa. e) Hypopharynx:It is vestigial or reduces.
Feeding Mechanism: When at rest the mouthparts are folded down beneath the head. During feeding they become straight and shot out glossae and lick the nectar with the help of flabellum. The glossal toung thus smeared with nectar is rapidly retracted between labial palp and galeae. As a result the nectar is squeezed off and deposited in a small cavity formed by paraglossae and sucked in by the capillary action of pharyngeal pump.
30 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
5. SIPHONING TYPE OF MOUTH PARTS: e.g.: Moths and Butterflies.
These are specially modified for taking nectar from the flowers. The galea of maxilla form into a slender, hollow, tubular structure which remains as an elongated coiled proboscis underneath the head during non feeding. Mandibles are totally absent. The labrum and maxilla palpi are reduced. Labium is modified in to a small basal plate possessing 3 segmented labial palps. The food channel is formed by the fusion of both the galeae. The nectar will be sucked from the flowers through muscular action
31 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
STUDY OF INSECT LEG
Insect legs are paired; hollow more or less cylindrical and jointed outgrowth of thoracic segments. They are the important locomotory organ.
Components of Insect Leg
Fig. Structure of Typical Insect Leg
Insect leg mainly consists of 5 parts viz.
1. Coxa: It is the functional basal segment and it is rigidly fixed to thorax.
2. Trochanter: It is very small and the second segment. It is articulated with coxa and fixed to femur.
3. Femur: It is the largest, strongest segment and is articulated with the tibia..
4. Tibia: It is equal or more than the length of the femur, articulated with tarsus.
5. Tarsus: it is the largest segment of the leg and usually devided into sub segments tarsomeres. The number of tarsomeres vary from 1-5. The tarsus at its end consists of pretarsus which is in the form of a pair of claws and cushion like pulvilli. In between the claws, if there is lobe like structure, it is known as “arolium” as in Orthoptera (grass hopper) and if it is bristle like structure, it is called “embodium” as in Diptera.
Legs of Larvae: Prolegs Thoracic legs mean true legs and abdominal legs mean Pseudo legsor false leg of larvae.There are two to five pairs. Abdominal legs are thick, fleshy and unsegmented and the tip (Planta) bear hooks called crochets, which help in cling the plant surface.
32 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
MODIFICATIONS OF LEGS IN DIFFERENT INSECTS
Type Legs modified Example purpose
Cursorial All legs Blister beetle, wasp Walking
Ambulatorial All legs Cockroach Running
Saltatorial Hind legs Grasshopper , gryllids Leaping and jumping
Fossorial Front legs Mole crickets, dung rollers Digging
Raptorial Front legs Preying mantids Preying (grasping )
Natatorial Hind legs Water beetle, water bugs Swimming
Scansorial All legs Head louse clinging
Prehensile All legs Dragon flies Catching prey, basketForming type
Antennal Front legs Honey bee For cleaningantennae cleaning legs
Pollen basket Hind legs Honey bee For collectingpollen and brush type and cleaning the body
Fig. Modification of insect legs
33 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
STUDY OF INSECT WINGS
Based on the presence or absence of wings, class insecta is divided into two subclasses; 1. Apterygota &2. Pterygota o The primitive apterygotes are wingless. E.g.: Silver fish and spring tails. o Secondarily wingless insects: Among pterygotes, some insects in their advanced stage of growth (Adult) shed the wings e.g. Bed bugs, head louse.
Based on the degree of development of wings the insects may be classified into three forms; 1) Macropterous, 2) Brachypterous & 3) Apterous.
The insect wings may sometimes possess some pigmented spot near coastal margin known as pterostigma or stigma as in Odonata (dragon flies and damsel flies).
Fig. Insect wing areas
A typical insect wing is triangular with three margins and three angles. The anterior margin strengthened by the costa is called coastal margin and the lateral margin is called apical margin and the posterior margin is called anal margin Three angles are, Humeral angle: between body wall and costal margin Apical or outer angle: between costal and apical margin Anal angle or tornus : between apical and anal margin Wings area are; The surface area of typical insect wing is divided in to two portionsi.e.Remegium and Vannal Area. The anterior (upper) part of the wing towards coastal margin where more no of longitudinal veins are present is called remigium. The posterior part of the wing where veins are sparsely distributed is known as Vannal Area, which is called as clavus in forewings and vanus in hindwings. Jugum is the inner most portion of the wing that is cutoff from the main wing by jugal fold.
Wings are very thin broad leaf like structures strengthened by a number of hollow narrow tubular structures called veins.
34 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Arrangement of veins on wing surface is known as Wing venation, which consists of two types of veins;
1. Longitudinal veins: Extend from base of the wing to the margin. They may be convex (∩) or concave (U)
2. Cross veins: That interlinks the longitudinal veins.
Fig. Hypothetical wing venation
Longitudinal veins:
1. Costa (C): It forms the thickened anterior margin of the wing (costal) and isun-branched and is convex
2. Sub costa (Sc): It runs immediately below the costa always in the bottom ofa trough between C and R. The two branches of SC are Sc1 and Sc2 and is concave
3. Radial vein (R): It is the next main vein, it divided in to two branches R1 and Rs (Radial sector). R1 goes directly towards apical margin and is convex; Rs is concave and divided in to 4branches, R2, R3, R4, and R5.
4. Media (M) It is divided in two branches 1. Media anterior (MA) which is convex and2. Media posterior (MP) and is concave. Media anterior is again divided into MA1 and MA2. Median posterior is again divided in to MP1, MP2, MP3, and MP4.
5. Cubitus (Cu): Cubitus is divided into convex CU1 and concave CU2. CU1 is again divided into CU1a and CU1b.
6. Anal veins (A):These veins are convex. They are individual un-branched, 1-3 in number.1 or 2 jugal veins (unbranched) are present in the jugal lobe of the forewing
35 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Cross veins: - Small veins often found inter connecting the longitudinal veins are called cross veins.
Humeral cross vein (h):between costa and subcosta. Radial cross vein (r): between radius and radial sector. Sectorial cross veins (s): between sub branches of radial sector. Radio medial cross vein (r-m): between radius and media. Medical cross veins: between branches of media. Medio-cubital veins: between media and cubitus.
DIFFERENT TYPES OF WINGS
1. Tegmina:Forewings are leathery and tough. They are protective in function. They protect the membranous hindwings. They are not used for flight.e.g.: forewings wings of cockroach, grasshopper
2.Elytra: The wing is heavily sclerotised without clear venation. Wing is tough and it is protective in function. They protect the membranous hind wings and abdomen. e.g.: Forewings beetles and weevils.
3.Hemelytra: The base of the wing is thick like elytra and the remaining half is membranous. They are not involved in flight and are protective in function. e.g.: Forewings of bugs.
4.Membranous: Naked thin with clear venation. e.g.: Both the wings of Dragonflies, bees and wasps, Hind wings of grasshopper, beetles,cockroach, both fore wings and hind wings of (wasp, bees, dragonfly and damselfly).
5. Scaly wings: Wings thin, membranous but covered with unicellular scales all over the surface. Scales are responsible for colour. e.g.: Both the wings of moths and butterflies.
6. Fringed wings: Wings are highly reduced with reduced venation. The wings are fringed with long marginal hairs giving a feather like appearance e.g. both the wings of thrips
7. Fissured wings: Forewings are longitudinally divided twice forming a fork like structure whereas hindwings are divided twice in to three arms. All the forks possess small marginal hairs.e.g.: Both the wings of plume moth
8. Halteres: In houseflies the hind wings are modified into small microscopic structures/ knobbed vibrating organs called haltere.They are divided in to three regions namely scabellum, pedicel and capitellum. They act as balancers. E.g. Hind wings housefly and front wings, male stylopids, mosquito and male scale insect.
9. Pseudohalteres: They are short and modified in to pseudohalteres which are dumbbell shaped. Eg: Front wings of Strepsiptera
36 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
ElytraHemelytraMembranous wings
Fringed wingsFissured wings Halteres
Tegmina wings Scaly wings
37 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
WING COUPLING APPARATUS/ORGANS/MECHNISMS
Among the insects with two pairs of wings, the wings may work separately as in the dragonflies and damselflies. For taking flight, insect need to keep both the fore and hind wings together as a single unit. The structures in the form of lobes, bristles, hairs or spines that help the wings to be together are known as wing coupling organs. 1. Jugate type or jugum type: The costal margin of the front wing possess a small lobe at the base called fibula which rest on the surface of the hind wing or sometimes engages with spines present on the upper surface of hind wings . e.g.: primitive lepidopterans of the family Hepialidae. 2. Frenulum/Franate/retinaculum type: The hind wings possess bristle or spine like structure or group of hairs known as frenulum.The forewings possess hook like retinaculum on anal side. During flight the frenulum passes beneath the retinaculum and thus the both the wings are kept together. e.g.: Fruit sucking moth. 3. Amplexiform: Costal margin of hind wing and anal margin of forewing overlap one above the other e.g.: butterfly 4. Hamuli/Hamulate : TheSmall curved hook like structures present on the costal margin of the hind wing known as Hamuli that fit into the upward fold of the anal margin of the forewings.e.g.hymenopterans (wasps and bees)
Jugate typeFrenulum type
Amplexiform type Hamuli type 38 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
SENSORY AND SOUND PRODUCING ORGANS
The sense organs in an insect body are distributed on different parts and respond to a given stimulus such as light, sound, touch, chemicals etc.
The sense organs may be classified as; 1. Photoreceptors(or) Visual organs- To detect light energy. 2. Auditory receptors (or) organs of hearing- To detect sound waves. 3. Chemoreceptor’s which respond to chemicals- To detect smell and taste. 4. Mechanoreceptor/Tactile receptors which respond to touch- To detect mechanical force 5. Thermoreceptor – To detect heat.
1. Visual organs or photoreceptors:These are two types, Compound eyes and Simple eyes.
I. Compound eyes:These organs possess the ability to perceive light energy and able to produce a nerve impulse. The compound eyes may be completely absent in insects like Protura or they may remain reduced in endoparasitic Hymenoptera. The compound eyes are present on either side of the head capsule of an adult insect and also in the nymphs of Exopterygota.
These are a pair and consist of number of individual units (or) facets called ommatidia. Function is to gather light.
Classification of Compound eyes based on image formation;
Apposition eyes:These are active during day time (diurnal insects);e.g.: butterflies Superposition eyes:These are active during evening and night time (Nocturnal insects); e.g.: moths
II. Simple eyes (or) ocelli:These are of two types
Dorsal ocelli:Seen in nymphs and adults of Hemimetabolous insects and adults of Holometabola.Dorsal ocelli are represented by fenestrae in cockroach. It perceive light to maintain diurnal rhythm. Lateral ocelli:Also known as stemmata. These are present on the lateral sides of the head of Endopterygote larva. It helps to detect form, colour and movement.
2. Auditory organs (or) organs of hearing:
Insects are provided with structures (or) organs that are able to perceive the sound waves (or) the aquatic water currents. Among the organs of hearing, the auditory hairs, tympanal organ and Jhonston’s organ are important.
39 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Auditory hairs :
These are present on the body of insects such as larvae of Lepidoptera which are developed from the modified epidermal cells. These respond to the sounds of air (or) water currents mediated by the hair sensillae (or) trichoid
Tympanal organ :
Tympanum is present one on either side of the 1st abdominal segment of short horned grasshoppers, on the base of foretibia in long horned grasshoppers and crickets, and on thorax or abdomen in Lepidoptera.
Jhonston’s organ:
It is present on the pedicel of antennae and functions asan auditory organ responding to air (or) water currents. They are absent in Collembola.
Pilifer of hawk moths (sphingid moths):
A unique auditory organ, sensitive to ultrasonic frequencies is found in the head of several species of Sphingidae.
3.Mechanoreceptor: (detect mechanical force)
Trichoid sensilla:Hair like sense organ. Sense cell associated with spur and seta. These cells are sensitive to touch and are located in antenna and mouthparts.
Campaniform / Dome sensilla:These cells are sensitive to pressure and located in legs joints and wing bases.
Chordotonal organ:The specialized sensory organs that receive vibration are subcuticular mechanoreceptors called chordotonal organ.
4.Chemoreceptors: (detect smell and taste):
It contains sensilla with one pore (uniporous) or more pores (multiporous).
♣ Uniporous chemoreceptors mostly detect chemicals of solid and liquid form by contact called gustatory receptorsand located in antennae. ♣ Multiporous chemoreceptor’s detect chemicals in vapour form at distant by smell called olfactory receptors and located in mouth and tarsi.
5. Thermoreceptor – (detect heat) Present in poikilothermic insects and sensitive to temperature changes. E.g. Bed bugs.
40 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
METAMORPHOSIS
Metamorphosis is derived from Greek word ‘Meta’ = Change, ‘morph’ = form or structure. Series of changes that takes place during the development of an insect from egg to adult are collectively known as metamorphosis. Metamorphosis include three developmental processes namely, growth, differentiation and reproduction which takes place in larval, pupal and adult stages respectively.
o Eclosion: The process of hatching of eggs after fully development of embryo called eclosion. o Instar: It is the forms of the body during two inter moults. The larva is known as first instar, immediately after hatching from egg, and as second instar after first moult and so on o Stadium: The interval or time period between two moults is known as stadium. o Exuviae: The skin shed during moulting process is known as exuviae. o Imago (or) Adult: It is the final stage of insect with well-developed organs for reproduction, which emerges out from pupal body. o Sub-imago: It is a pre adult stage with fully developed wings but without reproductive organs .E.g.: mayflies (Ephemeroptera)
Types of metamorphosis:
1. Ametamorphosis (Ametabolous)
2. Incomplete metamorphosis (Hemimetabolous)
3.Gradual metamorphosis: (Paurometabola)
4. Complete metamorphosis/Holometabolous
5. Hyper metamorphosis
1. Ametamorphosis: ♠ E.g.: Apterygote e.g.: silver fish, springtails. ♠ Insects do not undergo any metamorphosis. ♠ These insects have only three stages in their life namely egg, young ones and adult. ♠ The hatching insect resembles the adult in all respects except for the size and called as juveniles. ♠ Moulting continues throughout the life
41 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
2. Hemimetabola: (Incomplete metamorphosis) ♠ E.g. Dragonfly, damselfly and may fly. ♠ These insects also have three stages in their life namely egg, naiads and adult. Pupal stage is absent. ♠ The young ones are aquatic and are called as naiads. ♠ They are different from adults in habit and habitat. ♠ They breathe by means of tracheal gills. ♠ In dragonfly naiad the lower lip (labium) is called mask which is hinged and provided with hooks for capturing prey. After final moult, the insects have fully developed wings suited for aerial life.
3. Paurometabola: (Gradual metamorphosis)- ♠ E. g. grasshoppers, cockroaches, termites, true bugs, cicadas, and hoppers. ♠ It is also called as simple metamorphosis. ♠ The life cycle includes egg, nymph and adult stages. ♠ The nymph resembles the adult in all the characters except wings. Nymphs possess wing buds which transform in to fully developed wings in adult stage. ♠ Both nymphs and adults share the same habitat. ♠ In these insects, wings develop externally and hence are also called as Exopterygota. ♠ Pupal stage is absent hence, development is said to be direct and simple.
4. Complete or Holometamorphosis or indirect development: ♠ E.g. Butterfly, moth, Beetles, weevils, fly and bees. ♠ The life cycle includes four stages; egg, larva, pupa and adult. ♠ Larvae of butterflies are called caterpillar. ♠ Larva differs from the adult both in body structure and habits. Larva has both thoracic and abdominal legs, sometimes legs may be absent in larva, whereas adult has only thoracic legs. ♠ Compound eyes are absent in larva. ♠ Larva undergoes moulting to enter in to pupal stage from which the adult insect emerges. ♠ Wings develop internally during the pupal stage and hence, they are called Endoptreygotes.
42 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
5. Hypermetamorphosis: ♠ This is a peculiar type of development which consists of two or more types or forms of larvae in the life cycle of insects. ♠ In majority of the cases the first larval, instar is campodeiform and the subsequent larval forms depends on type and mode of life of the larva. E.g.: In blister beetle (Meloidae; Coleoptera), the first larval instar is campodeiform followed by scarabeiform larval type. SIGNIFICANCE OF METAMORPHOSIS
i. It helps the insect to tide over unfavorable climate conditions by entering into hibernation, aestivation and or diapauses. ii. It helps the insect to accommodate growth by periodical shedding of their old cuticle and by formation of new cuticle. iii. It helps the insect to reduce or avoid competition for food amongst themselves by either entering into inactive stage or by acquiring different feeding habits and habitats. iv. It helps the insect as a protective adaptation by a way of mimicry. i.e. resembles to the nature. v. It also serves as an important aspect in classification of insects.
SEASONAL ADOPTIONS
Diapause : -
It is the period of arrested growth or development in the life cycle of the insects during which the physiological processes like differentiation and reproduction are suspended. Diapause is represented by low rate of metabolism, low O2 consumption, low body weight, low body water content and vitamin deficiency in the blood. Diapause may occur in egg, larva, nymph, pupa or adult stage.
The occurrence of diapause during summer due to high temperatures is known as “aestivation” Whereas the period of inactivity during winter due to low temperatures known as “hibernation”.
43 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
IMMATURE STAGES OF INSECTS
Immature stages of exopterygote insects are known as Nymphs and endopterygote insects are known as Larvae.
Differences between Larva and Nymph
Sr.No. Larva Nymph
1. It is an immature stage, of Endopterygotes. Immature stage of exopterygotes 2. It undergoes holometamorphosis It undergoes hemimetamorphosis 3. Body is vermiform which differs from the adult Body resembles the adult in all the both in structure and feeding habits characters except wings 4. Consists of ocelli and reduced Antennae Have compound eyes and antennae 5. Possess both thoracic and abdominal legs Possess only thoracic legs. 6. The larva is different from adult in feeding habits Nymph resembles the adult in feeding and behaviour habits and behaviour 7. The larva enters pupal stage No pupal stage 8. E.g.: Lepidoptera, Coleoptera Hemiptera, Orthoptera.
TYPES OF LARVA
1. Protopod larva: E.g.: Endoparasitic Hymenoptera.
The larvae are partially developed. They possess well developed head and thoracic segments but lack segmentation in the abdomen. They possess rudimentary cephalic and thoracic appendages but no abdominal appendages. They have partially developed digestive system and underdeveloped respiratory and nervous systems.
2. Oligopod larva:
Thoracic legs are well developed. Abdominal legs are absent. These are classified in to two types’ viz., campodeiform and scarabaeiform.
44 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Differences between Campodeiform and Scarabaeiform
Sr. Campodeiform Scarabaeiform No. 1 The body is long and fusiform in shape Body is ‘C’ shaped 2 Body is dorso-ventrally compressed with Body is cylindrical or sub cylindrical, sclerotized cuticle stout and fleshy in nature 3 Prognathous type of head Hypognathous type of head 4 Long thoracic legs Short thoracic legs 5 Apair ofterminalabdominal processes (anal Absent cerci) are present 6 These are active Inactive 7 Predatory in nature Phytophagous 8 e.g. grub of antlion /grub of lady bird beetle. e.g.: grub of rhinoceros beetle/white grub
3. Polypod larva (Eruciform larva):
The larva possess well defined segmentation of the body with three pairs of thoracic legs, 2-5 pairs of abdominal legs (3rd, 4th, 5th, 6th and 10th abdominal segment. They are phytophagous and destructive.
Different types of polypod larvae:
A. Hairy caterpillar larval body is fully covered with hairsE.g.: Red hairy caterpillar, Castor hairy caterpillar
B. Sphingid caterpillar / larva the larva consists of a horn (or) hook on the dorsal surface of 8th abdominal segment. E.g.: Gingelly death’s head moth
C. Looper: Only two pairs of abdominal legs present on 6th and last abdominal segment during walking the insect body forms a complete loop like structure hence, the name looper.E.g.: Mango looper.
D. Semilooper: e.g.: Castor semilooper First two pairs of abdominal legs (on 3 rd and 4 th segments) are reduced, hence a part of the insect body forms a small loop during its movementE.g.:Castor semilooper.
4. Apodous larva:
These are characterized by the absence of trunk appendages (or) legs. They possess 3 pairs of sensory papillae in the place of thoracic legs. They are usually derived from Oligopod type.Based on the degree of development of the head capsule and its appendages, these larvas are divided in to 3 types.
45 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
a. Eucephalous: e.g.: Sub order Nematocera of Diptera, Mosquito(Culcidae) The larva consists of a well sclerotized head capsule. b.Hemicephalous. e.g.: Brachycera of Diptera, robberflies (Asilidae) Larva possess partially developed head capsule c. Acephalous e.g.: Cyclorrhapa of Diptera, Muscidae (houseflies)the larva are characterized by the absence of head capsule and mouth parts are represented by mouth hooks.
Appearance Larval Type Common Description Examples Name
Body cylindrical with short thoracic legs Moths Eruciform Caterpillar and 2-10 pairs of and fleshy abdominal butterflies prolegs
Elongated, flattened body with prominent Lady Campodeiform Crawler antennae and/or beetle, cerci. Thoracic legs lacewing adapted for running
Body robust and "C"- June shaped with no White beetle, Scarabaeiform abdominal prolegs grub dung and short thoracic beetle legs
Body long, smooth, Click and cylindrical with beetle, Elateriform Wireworm hard exoskeleton and Flour very short thoracic beetle legs
Body fleshy, worm- House fly, Vermiform Maggot like. No head capsule flesh fly or walking legs
46 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
TYPES OF PUPA
It is resting, inactive stage of the holometabolous insects and transitional phase during which the wings are developed and the insect attain matured sexual organs. The pupa is incapable of feeding, locomotion except in some cases where they crawl (Neuroptera) (Aphid lion), e.g.: mosquitoes. Later it emerges as adult, pupation may be takes place either in soil, or on the plant surface or within the webs.
Pupae are divided on the following bases;
I. Based on the presence or absence of powerful mandibles
Decticous pupae Adecticous pupae Possess relatively powerful mandibles which Do not possess the mandibles but with the are used for escaping of the adult from the help of other appendages, adults escape from cocoon i.e. to break the cocoon. e.g.: the cocoon e.g.: Lepidoptera, Diptera. Neuroptera
II. Based on the attachment on the appendages (or) shape of the pupae
1. Exarate pupa: e.g.:Coleoptera The pupae have appendages which are free without any secondary attachment to the body 2. Obtect pupa eg: Lepidoptera (moths) The pupae have appendages which are firmly pressed against the body and the pupa is highly chitinized. 3. Coarctate: e.g.: Diptera (housefly) The pupa remains enclosed in a puparium formed by the last larval skin and the pupa looks like a capsule or barrel. 4. Chrysalis: eg: butterflies It is an obtect type of pupa which has golden colouration and a stalk.
47 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Appearance Pupal Common Description Examples Type Name
Developing appendages (antennae, wings, legs, etc.) held tightly against Butterflies Obtect None the body by a shell-like and moths casing. Often found
enclosed within a silken cocoon.
All developing Beetles, Exarate None appendages free and Lacewings visible externally
Body encased within the Coarctate Puparium hard exoskeleton of the housefly next-to-last larval instar
It is an obtect type of pupa which has golden Chrysalis None butterflies colouration and a stalk.
48 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
STUDY OF INSECT DIGESTIVE SYSTEM
Digestive system of insect consists of Alimentary canal and Salivary glands.
Alimentary canal: It is a long, muscular and tubular structure. The alimentary canal in insects extends from mouth to anus which is divided in to three parts, foregut, midgut and hindgut.
1. Foregut (stomodaeum): Ectodermal in origin. Ectodermic Cells secretes cuticular layer called Intima. It is the anterior part of the alimentary canal which starts with the mouth cavity and ends with the gizzard (or) proventriculus. Terminal mouthparts lead into a preoralcavity. Preoralcavity between epipharynx and hypopharynx is called asCibarium. Preoralcavity between hypopharynx and salivary duct is Salivarium. It is divided in to pharynx,esophagus, crop and gizzard. i. Pharynx: Behind the mouth a well musculated organ called Pharynx is present which pushes the food into esophagus. Pharynx also acts as a sucking pump in sap feeders. It is the region between the mouth and oesophagus.It concerned with ingestion and back word flow of food. ii. Esophagus: It is a narrow Simple tube of the foregut through which the foods get transported from pharynx into the crop. iii. Crop: It is a sac like structure which is a dilated form and mainly serves the purpose of storage of food material. In honey bees crop is called as honey stomach where nectar conversion occurs. iv. Gizzard (Proventriculus): It formsthe last portion of foregut. This consists of the cuticular intima layer modified in to teeth like denticles that help for grinding the food material.It is found in solid feeders and absent in fluidfeeders or sap feeders.
49 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Stomodeal valve or cardiac valve: After gizzard the foregut forms into a stomodeal valve or cardiac valve which is surrounded by gastric (or) hepatic caecae. This prevents backward movement of food. Foregut opens in to midgut through stomodael / cardiac valve.
Proventriculus
2. Midgut (Ventriculus or mesenteron or stomach),(Middle) Endodermal in origin.Is concern with; i.Secretion of Enzymes,ii.Digestion of food, iii.Absorption of food. An endodermic cell does not secrete intima but instead of that secretes delicate membrane called Peritrophic membrane. Midgut consists of an inner delicate layer called peritrophic membrane secreted by the epithelial cells. The peritrophic membrane protects the tender epithelial cells of the midgut from abrasion by hard food particles. Present in solid feeders and absent in sap feeders. The midgut is a long tube it carries eight small blunt tubes known as gastric or hepatic or enteric caeca. It increase the surface area of malpighian tubules and they are secretary and absorptive in function.
Filter chamber: This is a characteristic arrangement of the midgut in hemipteran insects (fluid feeders). This is closely bound to either posterior part of midgut or the anterior hindgut and Malpighian tubules. Filter chamber enables the excess fluids including sugar in the food to pass directly from the anterior part of the midgut to the hindgut without passing through the middle portion of midgut thus preventing excessive dilution of haemolymph, enzymes and facilitate better enzyme activity.
50 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Filter chamber
Pyloric valve or proctodeal valve: Present between midgut and hingut, which regulate food flow.
3. Hindgut (Proctodaeum) (Posterior) Ectodermal in origin.Intima present. In termites, digestion takes place in colon of hindgutwhich secretes the enzyme cellulase for digest the wood material rich in cellulose. Anterior end of the hindgut can be marked by the presence of a set of malpighian tubules which are excretory in function. Hindgut is divided into 3 regions namely ileum, colon and rectum. i. Ileum is a small intestine (or) tube like structure. ii. Colon is a large intestine. iii. Rectum - The rectum may sometimes get differentiated into rectal papillae (or) pads which vary in number from 3-6. These are involved in reabsorption of water, salts from the faecal (waste) matter. Salivary glands:- These are a pair of glands involved in the secretion of salivary juices. These glands present either sides of esophagus which open at the base of the hypopharynx through small salivary ducts. In case of silkworm (or) lepidopteran larvae, the salivary glands produce silk and anti-coagulants in blood suckers like mosquitoes. Digestive enzymessuch as; ♠ Amylases–Helps for digestion of Starch. ♠ Lipases -Helps for digestion of Fats & Lipids. ♠ Proteases–Helps for digestion of Protein. ♠ Invertase – Helps for digestion of Sucrose.(Present in honey bees) ♠ Maltase - Helps for digestion of Maltose. ♠ Cellulase -Helps for digestion of Cellulose.(Present in termites)
51 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
STUDY OF INSECT NERVOUS SYSTEM
The nervous system functions as a link between the sense organs which respond to various external and internal stimuli and the effectors organs such as muscles, glands The sense organs include the structures with various sensilla that respond to sounds, weather factors, smell etc.
Nervous system consists of elongated cells which form the physiologically functional elements that are known as neurons. These neurons carry the information in the form of electrical impulses. It is a unit of nervous system.
STRUCTURE OF A NEURON
The nerve cells are called neurons which are derived from ectoderm.
Each neuron consists of a prominent nucleated cell body known as perikaryon (or) soma and an elongated cytoplasmic thin fibre called the ‘axon’ extends to make contact with other neurons or with effector organs, the muscles and group of small branches called the ‘dendrites’.
The axon gives lateral branches called collaterals. Both the axon and collaterals end in fine fibrils known as terminal arborizations.
The neurons get connected with each other by having a link between the terminal arborizations of the axon of one neuron and dendrites of the soma of other neuron through a ‘synapse’.
52 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Classification of neurons:
I. Based on their structure:
1. Unipolar / monopolar:Have a single axon without collaterals and dendrites.
2. Bipolar:Have either collaterals or dendrites in addition to axon.
3. Multipolar:Neurons have an axon with several collaterals and dendrites
II. Based on function: 3 kinds of neurons.
1. Sensory / afferent:Present just beneath the integument and associated with sensory organs. Carry impulses from sense organs to the central nervous system.
2. Motor / efferent neurons:Always unipolar / monopolar.Carry impulses from central nervous system to the organs.
3. Association / internuntial neurons:Associated in between sensory and motor neurons.
The point at which neurons receive information from or convey to another neuron is known as synapse. Synaptic gap is approximately 100 0A (20-25nm).
Nervous system can be grouped in to three;
1. Central nervous system (CNS)
2. Visceral or sympathetic nervous system
3. Peripheral nervous system
53 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
1. CENTRAL NERVOUS SYSTEM (CNS)
Insect have a decentralized nervous system.
The group of nerve cells or neurons is called ganglion.
CNS consists of double series of ganglia joined together by longitudinal and transverse fibers.
Generally each body segment possesses a pair of ganglia, so closely united as they appear to be one.
The ganglia of adjoining segments are joined together by longitudinal fibers called as connectives.
The ganglia of same segment unite by transverse fibers called as commissures.
CNS consists of brain(supraoesophageal/cerebral ganglion), sub- oesophagealganglion and ventral nervecord.
54 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Brain (Supra-oesophageal ganglion): It is present in the head above the oesophagus in the head. It is formed by the union of the ganglia of first 3 segments of the head. Brain is divided into protocerebrum, deutocerebrum and tritocerebrum.
Protocerebrum:
It is also known as fore-brain. It is formed by the union of the ganglia of pre- antennarysegment and forms the greater part of the brain. It gives nerve connection to the compound eyes and ocelli. It is bilobed and continuous laterally with the optic lobes.
Deutocerebrum:
It is also known as mid-brain. It is formed from the ganglia of antennary segment and it gives nerve connection to the antenna. Tritocerebrum : It is also known as hind brain. It is formed by the union of ganglia of intercalarysegment and is relatively small. It gives nerves to the labrum. Sub-oesophageal ganglion: It is present in the head below the oesophagus in the head. It is formed by the union of ganglia of the gnathocephalic segments. It gives nerves to mandibular, maxillary, labialsegment, salivaryducts, part of cervical muscles in the neck region and corpora allata. Ventral Nerve Cord (VNC): Ventral nerve card consists of a chain of segmented ganglia connected by means of longitudinal connectives and transverse commissures. In thorax, there are 3 ganglia. It controls the locomotory organs and gives nerve connection to the legs and wings called thoracic ganglia. In abdomen, there are about 8 ganglia. Each ganglion gives off nerves to respective segments.
55 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Mechanism of impulse conduction
Conduction of nerve impulse is mainly of two types-
1. Axonic- Electrical conduction through Na and K ionic movement
2. Synaptic- Bio-Chemical transmission (Acetylcholine production)
In axonic conduction ionic composition varies between inside and outside of axon resulting in excitable conditions, which leads to impulse conduction as electrical response. In synaptic conduction neurochemical transmitters are involved in the impulse conduction through the synaptic gap. Neurotransmitters and the type of reactions helping in the impulse conduction are as follows.
Acetyl CO-A + Choline chlorideAcetylaseAcetyl choline
Acetyl Choline Esterase
Acetyl choline Choline + Acetic acid
56 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
REPRODUCTION IN INSECTS
The reproductive system is divided in to two parts namely, internal genitalia and external genitalia. The internal genitalia serve to the development of germ cells. The external genitalia accomplish the union of two sexes and enable the female to deposit eggs.
Female reproductive system The main functions of the female reproductive system are egg production and storage of male's spermatozoa until the eggs are ready to be fertilized.
It consists of; A pair of ovaries which possess number of ovarioles, A pair of oviducts, A common oviduct / Median oviduct , spermatheca , A pair of accessory glands and Bursa copulatrix/copulatory pouch/genital chamber/vagina
1. Ovaries : These are the prominent visceral organs present on the either side of alimentary canal. These are paired in structured mainly covered with fat body and trachea.
Each ovary consists of eight ovarioles or egg tubes. It consists of 3 parts namely; Terminal filament, Egg tube, Pedicel.
The functions of ovary are production of eggs or ova and storage of male's spermatozoa.
57 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Types of ovarioles:-
Based on the presence or absence of nutritive cells and their location ovarioles are categorized in to two; i. Panoistic - In these, the nutritive cells are absent. e.g.: Odonata, Dictyoptera, Orthoptera and Ephemeroptera ii. Meriostic - They contain trophocytes / nutritive cells which vary in their position. Based on the position of trophocytes Meriostic ovarioles are classified into; Polytrophic - e.g.: Mecoptera, Dermaptera, Psocoptera Acrotrophic (Teletrophic) - e.g.: Hemiptera and Coleoptera
2. Lateral oviducts: Proximal end of the ovarioles of each ovary join to form a lateral oviduct on each side. Function is to transfer the eggs form ovary to the median oviduct.
3. Median Oviduct: Two lateral oviducts combine to form a median oviduct.
4. Vagina: (genital chamber) Median duct opens in to a tubular genital chamber or vagina formed by invagination of body wall from VIII segment.
5. Bursa Copulatrix:
In some insects the genital chamber or vagina develops a separate pouch called Bursa Copulatrix in to which insects have two reproductive openings
One is vulva for receiving the sperms open on VIII sternum and another one is ovipore or gonopore on IX segment for discharging eggs. E.g.: Lepidoptera and water beetles.
6. Spermatheca:
It is a sac like structure consisting of a spermathecal gland and opens in to vagina through spermathecal duct.
This is mainly used for temporary storage of sperms.
It also produces some fluids responsible for longevity of sperms cells for several hours.
7. Accessory glands: (collateral glands) These are a pair structured which open in to the distal portion of vagina.
They secrete the sticky substance responsible for the formation of ootheca of cockroach, preying mantid and poisonous secretions in case of Hymenoptera.
These sticky substances are useful for attachment of egg to the substrate on which they are laid.
58 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Oogenesis-The process in which primary oocyte developed in to fully developed ova is called oogenesis. Difference between male and female reproductive system Male reproductive system Female reproductive system A pair of testes composed of follicles or A pair of ovaries which possess number of sperm tubes. ovarioles. A pair of vasa deferens. A pair of oviducts.
Seminal vesicle. A common oviduct / Median oviduct.
Ejaculatory duct. A spermatheca.
Accessory glands. A pair of accessory glands. Genitalia. (aedeagus or penis) Bursa copulatrix/copulatrix pouch/genital chamber/vagina.
Male reproductive system
The main functions of the male reproductive system are the production and storage of spermatozoa and their transport in a viable state to the reproductive tract of the female.
A male reproductive organ consists of;
A pair of testes composed of follicles or sperm tubes A pair of vasa deferens, seminal vesicle ejaculatory duct accessory glands Genitalia.
59 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
1. Testes:
These are paired in structured &lie in visceral cavity above the alimentary canal. Each testes are well supplied with trachea and fat body tissues. Each testis consists of number of oval shaped structures known as follicles or sperm tubes. Each follicle has a layer of epithelial cells. The entire follicle is covered by a peritoneal membrane whereas the testes are completely enveloped within a coat known as scrotum. The functions of testes are production and storage of spermatozoa.
2. Vasa differentia:
These are the long tubes formed by the union of vasa efferens which receives the sperms from testis and allow their transport to the ejaculatory duct.
3. Seminal vesicles:
Each vasa deferens becomes enlarged posteriorly to form a sac like structure called seminal vesicle for storage of spermatozoa for some time.
4. Ejaculatory duct:
Both the vasa deferens of the two testes unites posteriorly to form a common median ejaculatory duct.
The terminal section of ejaculatory duct is enclosed in a finger like invagination of body wall called male copulatory organ or aedeagus or penis.
The function of aedeagus is that ejaculate the spermatozoa into the female genital tract.
60 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
5. Accessory glands:
These are 1-3 pairs of glands which open in to the ejaculatory duct
In most cases their secretion mix with spermatozoa. These glands are called mushroom glands in cockroaches and mantid because of their appearance as mushrooms.
This secretion facilitates sperm transmission from male to female.
Types of Reproduction
1. Oviparity:
Insects reproduce by laying eggs by the female which later hatch and produce the young ones. e.g.: moths and butterflies. (Higher order insect)
2. Viviparity:
It is the phenomenon of reproduction where the female gives birth to the young ones instead of laying eggs.Viviparity is classified in to 4 types. i) Ovo-viviparity:
Insects retain the eggs within the genital track until the eggs are ready to hatch (or) giving birth to young ones. e.g.: Thysanoptera (Thrips)
(ii) Adenoparous viviparity:
It is a type of viviparity where the eggs have sufficient yolk, complete their embryonic development and retain in the uterus. Eggs hatch and the young ones get nourishment from special nourishment glands called milk glands.
(iii) Pseudoplacental viviparity:
It is a phenomenon where insect have eggs with little (or) no yolk. Hatching takes place within the mother and the nourishment for the young one is received through embryonic maternal structure called pseudoplacenta e.g.: Psocoptera, Dermaptera, aphids etc.
61 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
(iv) Haemocoelous viviparity:
It is a type of reproduction where the eggs are retained within the haemocoel and the embryonic development as well as the nourishment of young one takes place through the transfer of nutrients from the haemolymph of mother. e.g: strepsipterans & some larvae of cecidomyids (Diptera).
3. Parthenogenesis:
It is the ability of the females to reproduce without fertilization / copulation with males. This usually occurs due to the genetic characters, due to heredity, failure in finding a mate, hormonal changes within the body and weather factors. . e.g.: aphids.
4. Paedogenesis (or) Neoteny:
It is a phenomenon where the immature insects or stages give birth to young ones. This usually occurs due to the hormonal imbalance. Most of the insects which reproduce by paedogenesis also reproduce by parthenogenesis. e.g.: cecidomyids. (Mustad sawfly).
5. Polyembryony:
It is a type of reproduction where insects reproduce by giving birth to two or more young ones instead of a single one, as two or more embryos are produced from a single egg. e.g.: endoparasitic Hymenoptera like platygaster.
6. Hermaphroditism:
It is a type of reproduction where both male and female gonads are present in the same individual. It may be a functional hermaphroditism as in case of Icerya purchsi (scale insect)(or) nonfunctional as in case of stonefly, Perla marginata.
7. Castration:
It is a type of reproduction where the separation of the individuals occurs mainly due to the development of the reproductive organs. The insects with well-developed ovaries develop in to females (queens), the insects with well-developed testis develop in to males (drones) and insects with underdeveloped ovaries develop in to workers. e.g.: social insects such as honey bees.
62 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
STUDY OF INSECT RESPIRATORY SYSTEM
It is also called as tracheal system.
In insects, exchange of gases takes place through tubular structures, called trachea.
They are distributed throughout the body collectively forming tracheal system.
These trachea open outside on the body wall through small openings called spiracles.
Spiracles occur on the pleural surfaces of the body, one on either side of each segment.
The tracheas are divided into very fine branches known as tracheoles. They supply oxygen to the body tissues. These tracheoles are formed in to cells called ‘tracheoblast’
The tracheal system with functional spiracles is called the open tracheal system and with non-functional spiracles is called closed tracheal system.
Tracheas are fine elastic tubular structures which are ectodermal in origin.
A spiral thickening throughout the length of the tube of trachea. These spiral thickenings are known as ‘taenidia’ which give support to the trachea without being collapsed when there is no air.
63 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Structure of trachea
Differences between trachea and tracheoles
Trachea Tracheoles These arelargetubesrunningfrom spiracles. Fine tubes arising distally from trachea. Taenidia present. Absent. Intima layer isshedduringmoulting. Intima layer is retained, unchangedduringmoulting. Never become intracellular. Intracellular. Theintimalayerconsistsofprotein– Chitin– protein matrix present, chitinmatrixwithresilin. resilinabsent.
Tracheal trunks:
The trachea coming from spiracles throughout the body join with those of neighboring spiracles forming ‘longitudinal trunks’. Likewise, these tracheas by combining with those coming from dorsal, lateral and ventral sides of the body fuse to form transverse commissures and longitudinal connectives.
All these in total form into dorsal trunk, lateral trunks which are two in number and one ventral trunk.
The dorsal trunk supply oxygen to proximal part of the body as well as to heart whereas the ventral supplies to then central nervous system. The two lateral longitudinal trunks spread tracheoles to alimentary canal, legs, gonads and wings.
64 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Head do not contain spiracles, air is supplied through the first pair spiracles by means of two main branches of the dorsal longitudinal trunk, where one branch supply O2 to eyes, antenna, brain; other branch to mouthparts and muscles of the head.
Tracheal system (dorsal tracheal trunks)
Spiracles:
They are the openings of the internal tubular trachea.
Except in Diplura, in all the orders, spiracles are absent in prothorax and distributed in meso, metathorax and abdomen.
A total of 10pairs are present in general, 2 pairs in thorax and 8 pairs in abdomen.
Spiracles are situated on pleural surface. They consist of a small ring like sclerite at opening called ‘peritreme’ leading to a cavity known as atrium.
The closing and opening of spiracles is accompanied by atrial valve lined with fibrous processes and form so called felt chamber which reduces water loss in the absence of closing mechanism.
65 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Structure of spiracle
Classification of tracheal system based on number and arrangement of functional spiracles: (Types of respiration).
1. Holopneustic:
These are primitive type with 2 pairs of spiracles on thorax and 8 pairs on abdomen. All the spiracles are functional. 1 + 1 + 8.
E.g. dragonflies, grasshoppers and cockroach.
2. Hemipneustic:
One or more pairs of spiracles become non-functional. They are; a) Peripneustic: Metathoracic spiracle is closed. 1+ 0 + 8. e.g.: larvae of Lepidoptera, Hymenoptera, Coleoptera. b) Amphipneustic: only mesothoracic and last pair of abdominal spiracles is open. 1 + 0 + 1. e.g: larva of cyclorrhaphan Diptera. c) Propneustic: Only one pair i.e. mesothoracic spiracles are open,
1 + 0 +0 e.g.: mosquito pupa. d) Metapneustic: only last pair of abdominal spiracles is open.
0 + 0 + 1. e.g.: mosquito larvae. e) Apneustic: No functional spiracles. e.g: mayfly larva, nymph of Odonata
3. Hypopneustic:
1 or 2 pairs of spiracles may completely disappear or absent e.g.: Siphunculata, Mallophaga
4. Hyperpneustic:
More than 10 pairs of spiracles are present e.g.: Japyx sps. (dipluran)
66 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
STUDY OF INSECT CIRCULATORY SYSTEM
There are two types of circulatory systems in the animal kingdom.
In many animals, the blood travels through vessels like arteries, capillaries and veins. This is known as closed type of circulatory system.
In insects the blood flows through the body cavity (i.e, heamocoel) irrigating various tissues and organs. It is known as open type of circulatory system.
Haemocoel:
Haemocoel of the insects is divided into 3sinuses(or) regions due to the presence of two fibro muscular septa (or) diaphragms composed of connective tissues.
Dorsal or Pericardial Sinus: The area lying in between the tergum and dorsal diaphragm. It contains heart.
Ventral or Perineural Sinus: The area lying in between the sternum and ventral diaphragm. It contains nerve cord.
Visceral Sinus: The area in between dorsal and ventral diaphragms. It harbour the visceral organs like alimentary canal and gonads.
67 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Main sinuses of haemocoel
Dorsal blood vessel: . It is the principal blood conducting organ in insects which remain closed at the posterior end and opens anteriorly in to the head. . It is divided into an anterior aorta and posterior heart
1. Aorta:
It is the anterior part of the dorsal blood vessel.
Its functions as principal artery.
It is present in the thoracic region and opens in to the head near the brain.
Its attachment with the heart posteriorly is marked by an aortic valve.
2. Heart:
It is the posterior part of dorsal blood vessel extending up to the terminal end of the abdomen.
Heart remains in position with the help of alary muscles. These alary muscles appear to be distributed fan like over the heart.
Heart consists of number of chambers marked by constrictions and the presence of the opening called ‘ostia’ which allow the entry of blood from pericardial sinus in to the heart.
The number of Ostia depends upon the number of heart chambers which will be usually 9.
Heart mainly functions as the pumping organ in to the aorta.
Accessory pulsatile organs:
68 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
An insect consists of sac like structures called accessory pulsatile organs, which are present at the base of the appendages such as wings, legs and antenna. They pulsate independently and supply adequate blood to the appendages.
Circulatory system
Process of blood circulation:
Heart mainly function as a pulsatile organ whose expansion and contraction leads to blood circulation.
It takes place generally in an anti-clock manner starting from posterior end to the anterior end in a forward direction.
Circulation of blood takes place in two phases due to the action of the alary muscles as well as the muscles of the walls of the heart.
The two phases are;
1. Diastole: During which expansion of heart takes place.
2. Systole: Contraction of heart takes place.
1. Diastole:
Expansion of heart (diastole) occurs, when the alary muscles that are spread fan like over the heart and connected to the tergum get contracted. It results in increase of volume of heart and decrease in the area of pericardial sinus. This creates a pressureon the blood in pericardial sinus forcing the blood to enter into the heart through the Ostia.
69 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
These ostia allow only the entry of blood from the sinus in to the heart and prevent its backflow from the heart to the sinus.
2. Systole:
Contraction of heart (systole) is brought about by the expansion of the alary muscles as well as contraction of the muscles of the heart wall. This creates pressure on the blood within the heart leading to its forward movement in to the aorta. From the aorta blood enters in to the head and flows back bathing the visceral organs in the visceral sinus and neural cord in the perineural sinus.
The short period of rest between diastole and systole called as diastasis.
The rate of heart beat generally varies with the body temperature and physiological conditions of the body which in turn differs between species (or) between stages of the insects.
Properties of blood:
1. Blood is colourless (or) green (or) yellowish with different types of haemocytes and plasma. Green colour is due to chlorophyll dissolved in the plasma and red colour is due to haemoglobin. 2. Blood covers up 5 – 40% of the total body weight that vary with the sex and stage (or) age of the insect. 3. Insect blood contains proteins, lipids, sugars, organic acids, phosphates, pigments, uric acid etc. 4. The insect blood of phytophagous insect is rich in ‘K’ where as that of carnivores is rich in ‘Na’. 5. Specific gravity of the blood varies from 1.01 to 1.06. 6. pH of the blood generally varies from 6 to 7. 7. The blood sugar of insects is trehalose. 8. Blood lacks vitamin ‘K’
Functions of blood:-
1. Transport of minerals or food materials:blood transports minerals, digested products, hormones to different parts of the body. 2. Water storage:Blood stores water for the tissues. 3. Helps for moulting:Blood helps during the process of moulting for splitting up of the old cuticle.
70 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
4. Encapsulation: To protect from the large metazoan parasites, the haemocytes of blood, become aggregated around the foreign body forming a capsule of 2-3 layers. This leads to the death of the foreign bodies due to lack of O2 supply. 5. Phagocytosis: To get protection from microorganisms like bacteria, viruses and fungi, the haemocytes completely engulf the foreign body and gets autolyzed.(This is the principal function of haemocytes). 6. Immunity: Blood gives immunity by producing antibodies to restrict further infections. 7. Connective tissue formation: Blood provides lipoproteins that are necessary for the formation of the connective tissue. 8. Wound healing (or) coagulation :Haemocytes extend pseudopodia which forms a cellular network over the wounded site (or) plasmtocytes coagulate forming a plug over the wound (or) haemocytes are arranged in to multi layered sheaths over the wounded site, thus helping in wound healing. 9. Detoxification: As the haemocytes are capable of detoxifying the toxic chemicals, insects get the ability to resist the toxic effects of chemicals. 10. Reflex bleeding: It is a phenomenon where emission of blood occurs through the pores (or) slits of the cuticle which mainly helps the insects for getting protection from their natural enemies.
STUDY OF INSECT EXCRETORY SYSTEM
What is excretion? “It is simply removal of the unwanted metabolic end products or some of the nutrients in excess form out of the body.”
Why it is necessary? A constant maintenance of level of salt and water and also osmotic pressure in the hemolymph.
The organs of insect body, involved in the elimination of excess or unwanted materials either toxic or not useful, are together known as excretory system.
The organs that are involved in the process of excretion are; 1.Malpighian tubules 2. Integument or body wall 3. Tracheal system 4. Alimentary canal 5. Nephrocytes
71 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
6. Urate cells 7. Oenocytes 8. Labial glands and 9. Chloride cells
1. Malpighian tubules:
These are discovered by an Italian scientist, Marcello Malpighi in the year 1669, which were named after him by Heckel in 1820. The Malpighian tubules long, tubular structures which open proximally in between midgut and hindgut and closed distally, floating freely in the haemolymph. Malpighian tubules vary in their shape and size. They may be simple or branched. Their number varies from 2-250 (2 in scale insect and 250 in locust, 60 in cockroach, 6 in moths and butterfly, 4 in bugs ). Malpighian tubulesare absent in aphids and Collembola. In some of the insects such as caterpillars and coleopterans(Beetles & Weevils), the distal ends of the Malpighian tubules get reattached to the alimentary canal by opening in to the rectum of hindgut. This condition is called ‘cryptonephridial condition’. Thecryptonephridial arrangement is concerned with reabsorption of water from rectum.
72 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Functions of Malpighian tubules:
1. This is the main organ of excretion and osmoregulation. It involved in regulation of salt, water and nitrogenous waste material.
2. Helps in the process of excretion or removal of waste products in order to regulate the internal body environment by maintaining ionic and water balance.
3. In case of glow worms (Fireflies), the distal ends of tubules produces light energy.
4. It also helps in the storage of Ca necessary for the processes such as hardening of puparium.
5. In case of aphid lion the secretions of the tubules produce stalked eggs.
6. In case of spittle bugs spittle around the immature stages is also a Malpighian secretion.
2. Integument:
Through the process of moulting, insects remove the waste nitrogenous products, i.e. they are deposited in the form of exuviae. In some insects, where respiration occurs through body wall, CO2 is removed through integument as waste product (cutaneous respiration).
3. Tracheal system:
The respiratory tubes, the trachea which are distributed throughout the body, function
in elimination of CO2 through spiracles. 4. Rectum:
Rectum plays an important role in excretion by reabsorbing the water from faeces.
Accessory organs of excretion-
5. Nephrocytes:
These are the special cells that sieve the haemolymph and are distributed in the body cavity. Nephrocytes are cells that take up foreign chemicals of relatively high molecular weight which Malpighian tubules may be incapable of dealing with.
6. Oenocytes:
These are large cells and are usually present near the abdominal spiracles. These are the specialized cells of haemocoel involve in excretion.
7. Urate cells: (Fat bodies)
73 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
In some of the insects body cells which store urea or uric acid in the form of granules are known as urate cells. Preserved uric acid can be utilized subsequently. These are present when Malpighian tubules are absent or may become nonfunctional. In some of the insects such as cockroach, the waste material in the form of urea or uric acid is stored throughout its life in the fat body cells without any harmful effect. This phenomenon of storage of urea / uric acid in the fat body cells is called ‘storage excretion’ which is useful for supply of nitrogen, when insect feeds on nitrogen deficient food.
8. Labial glands:
These are seen in Collembola, Diplura, Thysanura. They consists of a sac like structures called ampulla that leads to a long coiled that open at the base of labium in the head. This gland helps to remove ammonia.
9. Chloride cells:
These are the cells distributed on the body of aquatic insects such as larva ofmayfly or stone fly. They absorb ions from salt water (body) and then excrete in to surrounding medium to compensate the changes in the ionic concentration of haemolymph. STUDY OF INSECT ENDOCRINE SYSTEM
There are two types of secretrory structures occur in insect.
1.) Exocrine glands:
It is a ducted glands and discharge their secretions outside the body. E.g. Wax glands, Lac glands, Mandibular glands, Maxillary glands, Labial glands, Silk glands, Repugnatorial glands, Attractant glands and Poison glands.
2.) Endocrine glands:
It is a ductless glands and their secretion (harmones) usually diffusing into the blood which transports them to all parts of the body. Insect endocrine system is structurally and functionally integrated with nervous system. It is also called as secretory system. They secrete harmones which travel in the blood to various organs of the body coordinating their long term activities. Endocrine organs are of two types,
1. Neuro-secretory cells in the central nervous system. 2.Specialized endocrine glands such as i) Corpora cardiaca 74 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
ii) Corpora allata iii) Prothoracic glands iv) Weismann’s Ring:
1. Neurosecretory cells:
These are typical neurons with secretory activity.
They produce harmones which act directly on effector organs which in turn are stimulated to secrete harmones.
They occur in the mid region of brain and central nervous system.
The secretions of neurosecretory cells are called brain hormone or activator hormones.
Large number of neurosecretory cellsmay be present in the nervous system and are threetypes.a) Median NSC of the brain (PTTH harmone), b) Lateral NSC of the brain: - They Stimulate protein synthesis, control water loss and Oocyte development and activity. And c) Ventral NSC of the other ganglia (ventral nerve cord):
These secretions are known to concern with activity, water regulation.
2. Corpora cardiaca:
They are paired structures, lying in close association with neurosecretory cells of brain.
Each corpus cardiacum is transversed by neurosecretory axons from the brain. Neurosecretions from brain, on reaching corpus cardiacum, is stored and periodically released into the blood.
3. Corpora allata:
They are glandular bodies, usually situated one on either side of the Oesophagous.
Under the influence of brain hormone, corpora allata secretes Juvenile hormone (JH) or neotenin which regulates metamorphosis or yolk deposition on eggs in insect.
JH helps to keep the insect in young stage only.
It is also called as Juvenile hormone (JH) or neotenin.
4. Prothoracic glands:
It is also known as ecdysial glands.
They are twoin number and placed mostly in prothoracic region.
75 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Prothoracic glands secrete moulting hormone (MH), called Ecdysone under the influence of brain hormone.
Moulting hormone helps in insects in the initiation and process of moulting.
5. Weismann’s Ring:
It is found in housefly, flesh fly and blow fly. A Small ring like structure present behind the brain and around the aorta, supported by tracheae. It contains three types of glandular cells homologous with other endocrine glands.
CLASSIFICATION OF INSECT
Insects are invertebrates grouped in the phylum Arthropoda (Arthro-joint, poda-foot) and subphylum Uniramia.
Characters of the Phylum Arthropoda are 1. Segmented body 2. Segments grouped into 2 or 3 regions (tagma) known as Tagmosis. 3. Renewable chitinous exoskeleton 4. Grow by molting. 5. Bilateral symmetry ofbody. 6. Body cavity filled with blood and called as haemocoel. 7. Tubular alimentary canal with mouth and anus at anterior and posterior ends. 8. Dorsal heart with valve like ostia. 9. Dorsal brain with ventral nerve cord. 10. Striated muscles (with dark and light bands). 11. No cilia (hair like vibratile structure on the surface of the cell). 12. Paired, segmented appendages
Phylum Arthropoda is classified in to 7 classes 1. Onychophora (claw bearing) e.g. Peripatus 2. Crustacea (Crusta - shell) e.g. Prawn, crab, wood louse
76 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
3. Arachnida (Arachne - spider) e.g. Scorpion, spider, tick, mite 4. Chilopoda (Chilo - lip; poda - appendage) e.g. Centipedes 5. Diplopoda (Diplo - two; poda- appendage) e.g. Millipede 6. Trilobita (an extinct group) e.g. Trilobite 7. Hexapoda (Hexa- six; poda-legs) or Insecta (In- internal; sect – cut) e.g. Insects.
1. Class : Onychophora ♠ Animals forms the connecting link between the phylum Annelida & Arthropoda ♠ Animals are terrestrial and worm like ♠ Body is unsegmented, externally with numerous pairs of unjointed legs
2. Class : Trilobita ♠ Animals are marine forms with 3 lobed molded body, Unsegmented head (Cephalon), flexible trunk (Thorax) and (Pygidium) unsegmented tail ♠ Head possesses single pair of antennae ♠ Body is unsegmented, externally with numerous pairs of unjointed limbs
3. Class: Crustacea ♠ Animals are predominantly marine ♠ Body is divided in to Cephalothorax & Abdomen ♠ Animals possess five pairs of legs and two pairs of antennae ♠ Respiration by means of gills 4. Class : Arachnida ♠ The body is divided into cephalothorax and abdomen. ♠ Bears four pair of legs ♠ Instead antennae Chelicerae & Pedipalpi present ♠ Respiration by lung books and tracheae
5. Class : Myriapoda ♠ The body is divided into head and trunk ♠ Bears single pair of antennae ♠ Each body segment bears appendages ♠ Respiration by lung books and tracheae Sub Class: Diplopoda ♠ Animals with two pair of legs to each segment Sub Class: Chilopoda
6. Class : Insecta
♠ The body is divided into distinct regions, i.e. Head, Thorax and Abdomen.
♠ Single pair of antennae on head.
♠ Three pairs of legs on thorax.
♠ Two pairs of wingson thorax.
77 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
♠ The genital opening are situated on 8th and 9th abdominal segments
♠ Respiration by means of tracheae
♠ Undergo Metamorphosis
♠ Possess exoskeleton made up of hard cuticle which plays important role for survival ♠ Excretion is mainly by malpighian tubules which help in maintaining ionicbalance.
Scientific Nomenclature: -
Caroles Linnaeus (1707 – 1778) in his tenth edition of ‘systema naturae’published in 1758 used the binomial system of nomenclature for the first time for both plants and animals. This double naming in Latin one for the genus and thesecond for the species has been universally accepted.
Taxonomy – (Taxis = arrangement & Nomus = laws)Taxonomy is the science of classification. It can be defined as placing biological organisms or forms in order. Simpson (1961) has defined taxonomy as the theoretical study of classification including basis, principles, procedures and rules. Taxonomy includes nomenclature and classification.
Systematics - The science of study of kind and diversity of organisms and any or all relations among them. Systematics includes taxonomy and evolution.
Systematic position of insect
Invertebrates
Kingdom: Animalia
Phylum: Arthropoda
Sub-phyllum: Uniramia
Class: Insecta/Hexapoda
Sub class: Pterygota /Apterygota
Order:
Suborder:
Super family:
Family:
Subfamily
Genus:
78 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Species
The basic biological unit in the classification is species.
Species:These are a group of individuals which are similar in their structure, capable of interbreeding and producing fertile off spring. Subspecies:It is an aggregate of phenotypically similar populations of a species and differing taxonomically from other populations of the species. Genus:A group of species having some definite similar characters or relationships is called a geneus. Subfamily:It is a group of allied genera to form a subfamily. Family:It is a taxonomic category containing a single genus or a group of genera of common phylogenetic origin which is separated from related families by a decided gap. Such families showing similar characters form order.
The class insecta is divied in to two subclasses Apterygota and Pterygota.
Class – Insecta
Sub class 1. Apterygota
Order 1: Thysanura (Bristle tails, Silverfish, firebrats)(Thysan-fringed, Ura-tail) Order 2: Diplura (Diplurans)(Di-two; Ura-tail) Order 3: Protura (Telson tails)(Pro-first, Ura-tail) Order 4: Collembola (spring tails, snow fleas)(coll-glue; embol-peg)
Sub class 2: Pterygota
Exopterygota (Insects having simple metamorphosis) Order 5: Ephemeroptera (May flies) Order 6: Odonata (Dragon flies & damsel flies) Order 7: Plecoptera (Stone flies) Order 8: Grylloblattodea (Grylloblattids) Order 9: Orthoptera (Locusts and grass hoppers) Order 10: Phasmida (Walking sticks, leaf insects & stick insects) Order 11: Dermaptera (Ear wigs) Order 12: Embioptera (Web spinners) Order 13 Dictyoptera (Cockroaches and mantids) Order 14: Isoptera (White ants or termites) Order 15: Zoraptera (Zorapterans) Order 16: Psocoptera ( Psocids, book lice) Order 17: Mallophaga (Bird lice) Order 18: Siphunculata or Anoplura (sucking lice) Order 19: Hemiptera (Plant bugs)
79 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Order 20: Thysanoptera (Thrips)
Endopterygota (Insects having complex metamorphosis) Order 21: Neuroptera (Ant lions and lace wings) Order 22: Coleoptera (Beetles, weevils) Order 23: Strepsiptera (Stylopids) Order 24: Mecoptera (Scorpion flies) Order 25: Siphonoptera (Fleas) Order 26: Diptera (Flies, midges, mosquitoes) Order 27: Lepidoptera (Moths and butterflies) Order 28: Trichoptera (Caddis flies) Order 29: Hymenoptera (Ants, bees, wasps)
The class Insecta is divided in to 29 orders (4 in Apterygota and 25 in Pterygota).
The class Insecta has two subclasses viz., Apterygota and Pterygota.
Sr. Apterygota Pterygota No. 1 Primarily wingless insect Winged or secondarily wingless insect 2 Metamorphosis is totally absent or slight present. Present 3 Mandibles articulate with head capsule at a single point. double 4 Pleural sulcus in thorax is absent. Present 5 Pregenital abdominal appendages Absent. present
The sub class Pterygota has two divisions viz.,Exopterygotaand Endopterygota
Character Exopterygota Endopterygota Wing development External Internal Metamorphosis Incomplete (Hemimetabola) or gradual Complete (Holometabola) Pupal stage Absent Present Immature stage Egg, Naiad or Nymph, Adult Egg, Larva, Pupa, Adult No. of orders 16 09 STUDY OF INSECT ORDERS
1. ORDER: ORTHOPTERA(Orthos - Straight; Ptera-wings) E.g.Grasshoppers, Locust, Katydids, Mole cricket, house and field cricket.
Economic Importance: Majority of insects are phytophagous like grasshopper, locust some create noisy loud sound.
Characters:
Antenna is filiform.
80 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Mouthparts are mandibulate. Head position is hypognathous. Prothorax is large and distinct. Legs are saltatorial type. Legs normally developed, or forelegs modified for digging (fossorial) as in mole crickets or hind legs modified for jumping (saltatorial) as in grasshopper. Forewings are leathery, thickened and known as Tegmina and Hind wings are membranous. Specialized stridulatory (sound-producing) organs are present. Usually males alone can produce sound. Auditory or tympanal (hearing) organs are also well developed and are located on either side of the first abdominal segment or at the base of fore tibia. Cerci are short and unsegmented. Metamorphosis is gradual. (simple or incomplete)(Egg – Nymph - Adult) Ovipositor is well developed in female on 7 & 8thabdominal sternum. Male genitalia on 9th abdominal sternum.
This order is sub divided into two suborders, viz., Caelifera and Ensifera.
Sr. Caelifera Ensifera No. 1 Antennae are shorter than bodyless than 30 Antennae are longer than body more segments than 30 segments 2 Tympanum is found on the lateral side of the Tympanum is found on the fore tibia. first abdominal segment. 3 Diurnal(Active at day) Nocturnal(Active at night) 4 Feed on monocot plants Feed on dicot plants 5 Eggs laid in soil. Eggs laid in plant tissue 6 Ovipositor is short Ovipositor is more or less elongate. 7 Stridulatory organ (Femoro-alary type) Stridulatory organ (Tegminal) 8 Family: Acrididae: Short horned Families: grasshoppers, Surface grasshoppersand 1. Tettigonidae:Long horned locusts. grasshoppers, Katydids and bush crickets. 2. Gryllidae: House and fieldCrickets. 3. Gryllotalpidae: Mole crickets. 2. ORDER: DICTYOPTERA(Dictyon - Network; Ptera – wings)
♣ E.g. Cockroaches and Preying Mantid
Economic Importance : Cockroaches are household pests and Mantid predatory in habit
Characters:
Head is usually hypognathous.
81 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Antenna is filiform/ cetaceous. Mouthparts are mandibulate type. Forewings are tegmina and Hind wings are large membranous. Prothorax with pronotum covering Cerci are short and many segmented. Fore legs is walking/raptorial type. Eggs are contained in an ootheca. Metamorphosis is gradual. (simple or incomplete) Female with reduce ovipositor on 7thabdominal sternum. Male genitalia on 9th abdominal sternum. Dictyoptera is divided into two suborders viz., Blattaria (cock-roaches) and Mantodea (preying mantids). The important families are Blattidae and Mantidae.
Differences between Blattaria and Mantodea
Sr. Blattaria Mantodea No. 1 Head is completely covered with Head is not covered with pronotum. pronotum. 2 Two ocelli are present. Three ocelli are present. 3 Legs cursorial (All pairs) Fore legs is raptorial type. 4 Proventriculus with powerful teeth. Proventriculus not powerful teeth. 5 Eggs laid in ootheca Eggs laid in spaumaline 6 Omnivorous Carnivorous 7 No mimicry found Mimicry found 8 Nymph not cannibalistic Nymph cannibalistic Family: Blattidae- e.g. Cockroaches Family: Mantidae- e. g. preying mantids
3. ORDER: ODONATA (Odous - Tooth; anus – having), E.g. Dragonflies and damselflies. Economic Importance: Adults are aerial predators. They are able to catch, hold and devour the prey in flight. Naiads are aquatic predators. Adult predacious on mosquitoes, Houseflies etc. and nymph feed on mosquito larvae. Characters: Medium to large sized insects. They are attractively coloured. Head is Mobile and attached to slender neck Compound eyes are large. Three ocelli are present.
82 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Antennae is filiform Chewing and biting type of mouth parts Wings are membranous. Wings have a dark pterostigma towards the costal apex. Prothorax is reduced; meso and meta thorax is fused. Basket like legs present to catch prey in flight Abdomen is long and slender. Metamorphosis is incomplete with three life stages. The naiad is aquatic. Labium is greatly elongated, jointed and bears two hooks at apex. It is called mask. It is useful to capture the prey. Respiration by means of rectal or caudal gills. Immature stage of Odonata is called “Naiads” There are three sub-orders. Anisoptera, Zygoptera and Anisozygoptera.
Differences between Anisoptera and Zygoptera
ANISOPTERA ZYGOPTERA
(Anisos = Unequal & Ptera = Wing) (Zygon = Equal & Ptera = Wing) Adult Characters 1. Strong fliers 1. Weak fliers 2. Compound eyes large meet each other 2. Compound eyes button like, wide apart (Holoptic) (Dichoptic) 3. Hind wings basally broader than 3. Both Pair equal with identical venation forewings 4. Wings spread laterally at rest 4. Wings held at an angle above abdomen NYMPH (Naid) CHARACTERS 1. Stout and robust 1. Weak and fragile 2. Rectal gills present 2. Caudal gills present 3. Jet propulsion Mechanism present 3. Absent
E. g. Dragonfly E. g. Damselfly
4. ORDERS: ISOPTERA(Iso - Equal; Ptera - wing)E. g. Termites (White ants) Economic Importance: Termites are nature's scavengers. They convert logs, stumps, branches etc, to humus. Many are injurious to crops, furniture and wood works of buildings
Characters:
They are ancient polymorphic, social insects living in colonies White, soft bodied insects. Antennae are short and moniliform.
83 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Compound eyes present in winged forms. Mouthparts are adapted for biting and chewing. Wings are membranous. Wings are present only in sexually mature forms during swarming season.(Deciduous type) Tarsi are always 4 segmented Circi are short External genital organs are lacking in both the sexes. Metamorphosis simple or incomplete. Caste system: Following are the difference castes that are usually seen in atermite colony. Workers is the damaging caste A) Reproductives Cast;- a) Primaryreproductive (King& Queen) b) Supplementary reproductive B) Sterile Cast;- a) Workers b) Soldiers
Important families:- 1. Termitidae- e.g. Termes spp, Odontotermes spp. 2. Kalotermitidae- e.g. Dry wood termites. 5. ORDER: THYSANOPTERA (Thysano: Fringed and Pteron: wing), E.g. Thrips
Economic Importance: Most of the thrips species belong to the family Thripidae and are phytophagous. They suck the plant sap. Some are vectors of plant diseases. Few are predators.
Characters: They are minute, slender, soft bodied insects. Mouthparts are rasping and sucking.
84 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Right mandible is absent Hence mouthparts are asymmetrical. Antennae short moniliform Fringed wings are present Prothorax is free and well develops. Abdomen is elongate with 10-11 segments, usually tapering posteriorly Cerci absent Metamorphosis is incomplete with inactive pupa like instars (Aberrant hemimetabola) Parthenogenetic type of reproduction is very common and in many species males are rarely seen. This order is subdivided into two suborders. 1. Terebrantia: Important family is Thripidae, e.g Onion Thrips 2. Tubulifera: Important family is Phaleothripidae e.g Olive Thrips
6. ORDER: HEMIPTERA (Hemi - half; Ptera – wing) E.g. Bugs, Aphids, Whiteflies, Mealy bugs, Scales etc
Characters: Head is opisthognathous. Mouthparts are piercing and sucking type. Forewings (Hemielytra) are either uniformly thickened throughout distally membranous. Cerci are always absent. Metamorphosis usually incomplete. Alimentary canal is suitably modified (filter chamber) to handle liquid food. There are two suboders viz., Heteroptera and Homoptera
Differences between Heteroptera and Homoptera
Sr. Heteroptera Homoptera No. (Hetero-different; Ptera-wing) (Homo-uniform; Ptera-wing) 1 Head is porrect or horizontal Head is deflexed 2 Pronotum usually large Pronotum small and collar like 3 Forewings hemelytra Forewings uniform in consistency 4 Wings fold flat over the body atrest Wings held roof like over the body 5 Tarsi – 3 segmented antennae 4-5segmented Tarsi 1-3 segmented antenna 3-
85 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
10segmented 6 odoriferous glands arepresent wax glands are present 7 Herbivorous, predaceous orblood sucking. Herbivorous 8 Both terrestrial and aquatic Terrestrial 9 Honey dew secretion uncommon Honey dew secretion common 10 Important families of heteroptera Important families of homoptera 1. Cimicidae: (Bed bugs) 1.Cicadellidae: (Leaf hoppers or 2. Tingidae: (Lacewing bugs or Tingid bug) Jassids) 3. Miridae: (Plant bugs or Leaf bugs) 2. Delphacidae : (Delphacids) 4. Lygaeidae: Dusky cotton bug 3. Aleyrodidae: (Whiteflies) 5. Pyrrhocoridae: Red cotton bug 4. Aphididae: (Aphids) 6. Coreidae: Rice earhead bug,Tur pod bug, 5. Coccidae: (Scale insects) 7. Pentatomidae: (Stink bugs, Painted bug) 6. Kerridae: (Lac insect) 8. Belostomatidae: (electric light bugs) 7. Pseudococcidae: (Mealy bugs)
7. ORDER: NEUROPTERA(Neuron-nerve; Ptera - wings), E. g. Green lace wings, Ant lions, Alder fly, Snake fly Economic Importance: Insects are predacious (on aphids, White flies, thrips) – beneficial, Dobson flies called hellgrammites use for fish baiting. Characters: They are soft bodied insects Antenna is filiform Mouthparts are chewing type in adults. Two pairs of similar membranous wings in rest form roof on abdomen Circi absent Larva is carnivorous, campodeiform Pupa is Exarate, decticous. Pupation takes place in a silken cocoon. Malpighian tubules are modified as silk glands. Abdomen without cerci. Metamorphosis complete type (Egg – Larva – Pupa - Adult) Classification: This order is subdivided into two suborders viz., Megaloptera and Planipennia.
Sub order: Planipennia: 1. Chrysopidae: (Green lacewings, Goldeneyes, Stink flies, Aphid lions) 2. Mantispidae: (Mantispidflies). 3. Myrmeleontidae: (Ant lions) 4. Ascalaphidae: (Owlflies)
86 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
8. ORDER: LEPIDOPTERA (Lepidos - scales; Ptera – wings)
E. g. Moths, Butterflies, Skippers
Characters: Head relatively small free with small neck. Compound eyes are relatively large; two ocelli present one on each side close to the margins of compound eyes. Mouthparts in adults are of siphoning type. Mandibles are absent. Antennae are clubbed in buterflies and filamentous in moths Wings are membranous and scaly. Wings are coupled by either frenate or amplexiform type of wing coupling. Larvae are called caterpillars usually polypod-eruciform type. Two to five pairs of fleshy unsegmented prolegs are found in the abdomen. At the bottom of the proleg, crochets are present. Pupa is generally adecticous and obtect Adults are harmless except fruit sucking moths. Undergo complete metamorphosis.
There are three sub-orders. Zeugloptera, Ditrysia, Monotrysia.
Sr. Zeugloptera Monotrysia Ditrysia No. 1 Adults with functional Adults without functional Adults without functional mandibles sometimes with vestigial mandibles mandibles 2 Female bursa copulatrix Female with 1 or 2 genital Female with opening bursa opening into common opening behind sternite copulatrix on sternite oviduct 3 Female insects have one Female insects have two pore. pores.
Important familyof suborder Ditrysia:- Family: Noctuidae - This is the largest family in this order. E. g. Army worms, cutworms, Spodoptera, Helicoverpa, Fruit sucking moth, Castor semilooper. Family: Gelechidae– E. g. Potato tuber moth, Pink bollworm, Groundnut leaf miner, Angoumois grain moth. Family: Pyralidae–E. g. Cotton leaf roller, Jowar stem borer, Wax moth Family: Pterophoridae–E. g. Tur plume moth Family: Arctiidae–E. g. Hairy caterpillar
87 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Family: Hesperiidae–E. g.Rice skipper Family: Shingidae–E. g. Sesamum and Sweet potato leaf eating caterpillar Family: Papilionidae–E. g. Lemon butterfly Family: Lycanidae–E. g. Anar caterpillar Family: Pieridae–E. g. Cabbage butterfly Family: Bombycidae–E. g. Mulberry silk worm Family: Saturnidae–E. g. Tasar and Erri silk worm Differences between moths and butterflies
Sr. Moths Butterflies No. 1 Nocturnal in habit Diurnal in habit 2 Antennae either Pectinate or bi Pectinate Antennae Clavate type plumose type 3 Ocelli Present Ocelli Absent 4 Mandibles Present Mandibles Absent 5 Wing coupling Frenate type Wing coupling amplexiform type 6 Abdomen Large and stout Abdomen Comparatively small and slender 7 Obtect pupa within a cocoon Obtect pupa without cocoon. 8 At rest, wings held roof like on body At rest, wings held erect straight upward.
9. ORDER: HYMENOPTERA (Hymen - membrane; Ptera - wings.) E. g. Wasps, bees, ants, sawflies, Parasitoids etc Economic Importance: Red ant, mustard saw fly are crop pest. Many insects are beneficial parasitoids or pollinators Characters:
This is the most beneficial order in the class insecta comprising of parasites, predators and bees involved in poliination and honey production. Most of them are social living Mouth parts are biting type modified for lapping or sucking Wings are membranous Wing venation ishamuli type. Abdomen is basally constricted. The first abdominal segment is called propodeum. It is fused with metathorax.The second segment is known as pedicel which connects the thorax and abdomen. Abdomen beyond the pedicel is called gaster or metasoma Larvae are known as grubs with well developed head and usually apodous and eucephalous Pupa exarate and a cocoon is generally present Metamorphosis complete and complex also. Fertilized eggs develop into females and males are produced from unfertilized eggs. Males are haploid and females diploid.
88 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
This order is subdivided into two suborders; Symphyta andApocrita Differences between Symphyta and Apocrita
Sr. Symphyta Apocrita No. 1 Abdomen is broadly joined to the thorax Abdomen is petiolated 2 Larva is a caterpillar and it belongs Larva is a grub and it belongs apodous eruciform type eucephalous type 3 Stemmata are present Stemmata are absent. 4 Both thoracic and abdominal legs are Legs are absent present 5 Ovipositor is saw like andsuited for Ovipositor is not saw like and is suited for piercing the plant tissues piercing in parasitic groups or for stingingin other groups. 6 Behavioural sophistication is less. Behavioural sophistication is more 7 They are phytophagous They are generallyparasitic 8 Important families: Important families: Tenthredinidae : (Sawflies) Apidae : (Honey bees) Vespidae: Wasps Megachilidae: (Leaf cutter bees) Formicidae: (Ants) Braconidae : (Braconid wasps) Trichogrammatidae: (Egg parasitoids)
10. ORDER: COLEOPTERA (Coleos - Sheath ; Ptera-wing), E. g. Beetles, Weevils
Economic Importance: It is the largest order. It includes predators, scavengers and many crop pests. They also damage stored products. Characters: They are minute to large sized insects. This is the largest order in class insecta comprising about 1/3rd or 40% of the known insect species. Mouthparts are chewing & biting type. Head position is prognathous type Antenna is usualy 11 segmented. Prothorax is large, distinct and mobile. Mesothorax and metathorax are fused with the first abdominal segment. Forewings are horny or leathery known as elytrait is not used for flight. Hind wings are membranous with few veins and are useful in flight. Legs well developed for walking, running. Cerci and a distinct ovipositor are absent. Metamorphosis is complete. Larvae are often called grubsit is campodeiform or eruciform. Pupae adecticous and Exarate.
89 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
This order is divided into four suborders, viz., Adephaga (devourers) and Polyphaga (eaters of many things), Archostemata (wood feeders) and Myxophaga (Found in wet places Difference between Adephaga and Polyphaga
Sr. Adephaga Polyphaga No. 1 Cicindelidae: (Tiger beetles) Meloidae: (Blister beetles, Oil beetles) 2 Dytiscidae: (True water beetles) Coccinellidae: (Lady bird beetles, Epilachna beetle) 3 Carabidae: (Ground beetles) Scarabaeidae: (white grub, Dung beetles) 4 Cerambycidae: (Mango stem borer, Grape stem girdler) 5 Bruchidae: (Pulse beetles, Seed beetles) 6 Tenebrionidae: (Rust red flour beetle) 7 Bostrychidae: (Lesser Grain borers) 8 Melolonthidae: (Chafer beetles, June beetles) 9 Dynastidae: (Rhinoceros beetles) 10 Curculionidae: (Weevils, snout beetles) 11 Chrysomelidae : eg. Red pumpkin beetle
Differences between Beetle and Weevil
Sr. Beetle Weevil No. 1 Mouthparts typically chewing type Mouthparts chewing type but modified into snout like structure. 2 Both pairs of wings present. Hind wing absent. 3 Antennae capitates/ serrate/ Lamellate Antennae clavate 4 Tarsi 3 to 5 segmented Tarsi 4 segmented 5 Larvae oligopod Larvae apodous
11. ORDER: DIPTERA(Di-two; Ptera-wing) E. g. Housefly, Fruit fly, Horse fly, Pod fly, Stem fly, Mosquito, Midges.Midge fly, shoot fly, gall fly Economic Importance: Considerable number of flies is predacious. some are act as a vectors for transmission of disease, fruit flies, leaf miners, stem fly and root maggots are crop pest Characters: They are small to medium sized, soft bodied insects.
90 Theory Notes on Fundamentals of Entomology Prof. Mochi A. S. (K. K. Wagh College of Agriculture, Nashik)
Mouth parts sucking type usually forming a proboscis. In many they are piercing and sucking and in others they are sponging type Antennae mostly 3 segmented and Aristate type Forewings are larger, membranous and used for flight. Hind wings are highly reduced, knobbed at the end and are called halters. Prothorax and metathorax are small and fused with large mesothorax Metamorphosis is complete Larvae of more common forms are known as maggots. They are apodous and acephalous (eruciform). Maggots mostly amphipneustic Pupa is generally with free appendages, often enclosed in the hardened last larval skin called puparium. Pupa belongs to the coarctate type. Legs well developed, tarsus usually 5 segmented pulvilli and an empodium usuallypresent This order is sub divided in to three suborders; Nematocera (Thread-horn), Brachycera (Short-horn ), Cyclorrhapha (Circular-crack
Comparative characters of these sub-orders
Sr. Nematocera Brachycera Cyclorrhapha No. 1 Antenna is long and many Antenna is short and Antenna is aristate in adult segmented in adult. few segmented in adult. 2 Larval head is well Larval head is retractile Larval head is vestigial with developed. into the thorax. mouth hooks. 3 Larval mandibles act Larval mandibles act Larval mouth hooks act horizontally. vertically vertically. 4 Pupa is weakly obtect. Pupa is exarate. Pupa is coarctate. 5 Adult emergence is through a Adult emergence is The split results due to the straight split in the thoracic through a straight split pressure applied by an region in the thoracic region. eversible bladder ptilinum in the head. 6 Pseudotrachae absent Pseudotrachae present Pseudotrachae present 7 Important families: Important families: Important families: Culicidae: Mosquitoes Asilidae: Robber flies Syrphidae; Syrphid fly Cecidomyiidae :Pady gall Tabanidae: Horse flies Tachinidae: Tachinid flies fly Trypetidae: Fruit flies Muscidae: House fly Agromyzidae: Tur pod fly, Leaf miner
91 Theory Notes on Fundamentals of Entomology