DOCSLIB.ORG

Seasonal Distribution of Fall Armyworm (Lepidoptera: Noctuidae) Host Strains in Agricultural and Turf Grass Habitats

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Seasonal Distribution of Fall Armyworm (Lepidoptera: Noctuidae) Host Strains in Agricultural and Turf Grass Habitats Exhibit 8b, #57 POPULATION ECOLOGY Seasonal Distribution of Fall Armyworm (Lepidoptera: Noctuidae) Host Strains in Agricultural and Turf Grass Habitats 1 ROD N. NAGOSHI AND ROBERT L. MEAGHER Center for Medical, Agricultural and Veterinary Entomology, Agricultural Research Service, U.S. Department of Agriculture, Gainesville, FL 32608 Environ. Entomol. 33(4): 881Ð889 (2004) ABSTRACT Male fall armyworm moths[ Spodoptera frugiperda (J. E. Smith)] were captured in pheromone traps over a 16- to 24-mo period in selected sites in southern Florida. Molecular markers were used to determine whether individuals were of one of two host strains (historically designated “rice-strain” and “corn-strain”). Trapsplaced in agricultural areasshoweda population peak in the spring (MarchÐMay) and fall (OctoberÐDecember), with a prolonged decline in numbers in summer (JulyÐOctober) and a smaller reduction in mid-winter (January). The host strain distribution during these periods varied signiÞcantly, suggesting strain-speciÞc and seasonal population patterns. Both strains were captured in substantial numbers during the spring peak, but surprisingly, only the rice-strain showed an increase in capture rates during the fall, despite the presence of sweet corn throughout this period. Trap captures in a sod (turfgrass) farm were composed almost entirely of the rice-strain and showed a bimodal seasonal distribution similar to that seen in the agricultural areas, with peaks in the spring and fall. These results represent the Þrst indication that the two host strains might have substantially different population dynamics in the overwintering agricultural areas of Florida and suggest that the rice-strain is the predominant fall armyworm pest during the fall and winter growing periods. It further indicates that the two strains can display a markedly different response to seasonal environmental cues. The implications of these Þndings on our understanding of fall armyworm migration are discussed. KEY WORDS fall armyworm, Spodoptera frugiperda, host strains, population dynamics FALL ARMYWORM, OR Spodoptera frugiperda (J. E. different plant cultivars, including transgenic Bacillus Smith), is periodically a signiÞcant pest of maize, sor- thuringiensis Berliner plants(Pashleyet al. 1987b, Jam- ghum, forage grasses for livestock, turf grasses, rice, janya et al. 1990, Quisenberry and Whitford 1988, cotton, and peanuts, and whose range extends from Adamczyk et al. 1997). Clearly strain-speciÞc differ- southern Canada to much of South America (Luginbill enceshave important ramiÞcationstoward the devel- 1928, Sparks1979). Complicating our understanding opment of effective control strategies, yet virtually of fall armyworm Þeld behavior isthe existenceof two nothing isknown about the behavior of the two strains sympatric and morphologically identical strains in the Þeld. (Pashley et al. 1985). The strains were identiÞed by Fall armyworms are not known to diapause and so molecular polymorphisms and deÞned by their host cannot survive the winters in temperate climes. This plant preferences, hence their designation as “host meansthat the infestationof much of the United States strains” (Pashley 1986). The rice-strain (R-strain) is originatesentirely from populationsoverwintering in typically found on rice and Bermuda grass, whereas southern Florida, southern Texas, and northern Mex- the corn-strain (C-strain) prefers Þeld and sweet corn. ico (Luginbill 1928, Mitchell 1979, Sparks1979, Pair et The two strains can be distinguished by strain-speciÞc al. 1986, Raulston et al. 1986). Population surveys in allozyme variantsand genetic markers(Pashley1989, southern Florida indicate a rise in the fall armyworm Lu et al. 1992, 1994, Lu and Adang 1996, McMichael population in the spring, followed by a rapid and and Prowell 1999). Host strains differ in larval devel- prolonged decline during the summer months (Pair et opment on host plants (Pashley 1988, Pashley et al. al. 1986, Mitchell et al. 1991). Thisdecline corresponds 1995), mating behaviors(Pashleyand Martin 1987, to, and presumably reßects, the northward migration Whitford et al. 1988, Pashley et al. 1992), use of food of thispopulation into northern Florida and southern resources (Veenstra et al. 1995), resistance to certain Georgia in April and May (Snow and Copeland 1969, pesticides (Pashley et al. 1987a), and susceptibility to Greene et al. 1971), which continuesinto the northern states by July and August (Mitchell 1979). It is spec- 1 E-mail: [email protected]ß.edu. ulated that thismigration allowsfall armyworm to 0046-225X/04/0881Ð0889$04.00/0 ᭧ 2004 Entomological Society of America 882 ENVIRONMENTAL ENTOMOLOGY Vol. 33, no. 4 avoid adverseweather conditionsdeleteriousto host Trap-S was place on the west side of a large sod farm plant development and to escape density-dependent (235 ha) in northcentral Collier County (26Њ21.051Ј N, natural enemies(Knipling 1980). However, the envi- 81Њ35.733Ј W). Year-round sod production was com- ronmental factorsthat trigger migratory behavior are posed of primarily St. Augustine grass [Stenotaphrum unknown. secundatum (Walt.) Kuntze], although there were If habitat-speciÞc factors initiate migration, we sections of bahiagrass grown (Paspalum notatum might expect the two host strains to differ in the timing Flugge.). These large turfgrass Þelds were bordered of their northward movement. In particular, the be- by areasof natural vegetation and a nurserycontaining havior of the corn-strain should be inßuenced by the trees and shrubs. planting and harvesting cycle for corn, whereas the Trap-C wasplaced adjacent to a large sweetcorn rice-stain would more likely reßect seasonal changes (Zea mays L.) Þeld in southern Miami-Dade County occurring in grasslands. Some evidence of strain-spe- (25Њ239.524Ј N, 80Њ28.854Ј W). Sweet corn production ciÞc differencesin population dynamicswere ob- in Miami-Dade County averagescloseto 6,000 ha (Li served in Louisiana, with the two strains showing peak et al. 2002a), with a planting season between early pheromone capture ratesat different timesof the year October and late January. Harvest is generally be- (Pashley 1988, Pashley et al. 1992). This could indicate tween January and May, and some growers produce differencesin the timing of the migration of the two two crops per season (OctoberÐDecember and Janu- strains into the tested area. aryÐMay). Planting in thisÞeld occurred in October We are currently studying the distribution of fall and December 2001Ð2003, with harvest in December armyworm strain populations in southern Florida us- and March 2002Ð2004. Many vegetable growersplant ing pheromone traps. Trap captures at three sites were a cover crop of a sorghum ϫ sudangrass hybrid (Sor- examined in particular detail because their respective ghum bicolor L. Moench) from June to September, but plant populationsallowed clear predictionsasto the Þeld adjacent to Trap-C wasallowed to go fallow. which strain should predominate. We found evidence For collectionsin November and December 2003, we for substantial and consistent differences in the sea- wanted to extend the test area and obtain a high sonal population dynamics of the two strains even in number of samples over the sampling period. In ad- collectionsmade from the samelocation. The impli- dition to Trap-C, which waskept in the original loca- cations of these results on our understanding of fall tion, two other trapswere used.Trap-C2 wasplaced armyworm migration and population behavior are dis- within 150 m of Trap-C and adjacent to a sweet corn cussed. Þeld. Trap-C3 (25Њ27.832Ј N, 80Њ29.488Ј W) waslo- cated Ϸ20 km east of Trap-C and adjacent to a sweet corn Þeld. Trap-T waslocated adjacent to a tomato Þeld and Materials and Methods across the road from a sweet corn Þeld in southern Trap Collection and Sites. We used pheromone Miami-Dade County (25Њ35.223Ј N, 80Њ29.488Ј W). trapsin three southernFlorida locationsto estimate Sweet corn was harvested soon after trap placement seasonal changes in population density during an (February 2002), and the land wascleared for a res- 18-mo period from January 2002 to July 2003. Male idential subdivision. Tomato production in Miami- adult mothswere captured in pheromone trapsplaced Dade County rangesbetween 1,500 and 5,500 ha, de- adjacent to a sweet corn Þeld, a mixed agricultural area pending on season and markets, and fruit is harvested with nearby tomato and sweet corn plantings, and a between December and May (Li et al. 2002b). Data sod farm growing turfgrass. We anticipated that the for thistrap wasnot obtained from 1 June 2002 to 1 July corn-strain would predominate during the growing 2002 because of a defective trap and heavy rains. seasons for the Þrst two locations, whereas the rice- Trapping was discontinued after 8 July 2003 because strain would be the primary population in the sod of continued vandalism. farm. Adult maleswere collected usingpheromone DNA Preparation. Individual adult mothswere ho- trapsaspreviouslydescribed(Meagher and Gallo- mogenized in 1 ml of homogenization buffer (0.03 M Meagher 2003). Standard plastic Unitraps were baited Tris-HCl at pH 8.0, 0.1 M NaCl, 0.2 M sucrose, 0.01 M with a commercially available fall armyworm phero- EDTA at pH 8.0, and 0.5% Triton X-100) in a 5-ml mone (3-component lure; Scenturion, Clinton, WA) Dounce homogenizer using either a hand pestle or a and contained insecticide strips (Hercon Environ- motorized mixer (Nagoshi and Meagher 2003). To mental Co., Emigsville, PA). Traps were placed
Load more

Recommended publications
  • Insect Pest Management in Soybeans 12 by G
    Chapter Insect Pest Management in Soybeans 12 by G. Lorenz, D. Johnson, G. Studebaker, C. Allen and S. Young, III he importance of insect pests in Arkansas Finally, it is important to determine what soybeans is extremely variable from year to management tactics are available and whether or year due in large part to environmental not they are economically feasible. T conditions. For example, hot, dry years favor many lepidopterous pests such as the soybean Insect Identification podworm and the beet armyworm; and when drought conditions occur, these pests usually are The three types of insect pests found in soybeans abundant. Many other lepidopterous pests, such as in Arkansas are: the velvetbean caterpillar and the soybean looper, 1. Foliage feeders, which comprise the biggest may cause problems following migrations from group of insect pests, southern areas, particularly in concurrence with winds out of the Gulf region where they are a 2. Pod feeders, which are probably the most common problem. Generally, insect pressure is detrimental to yield, and greater in the southern part of the state compared to 3. Stem, root and seedling feeders, which are northern Arkansas due to warmer temperatures and often the hardest to sample and are not detected closeness to the aforementioned migration sources. until after they have caused damage. Production practices also have an impact on the Some insects, such as the bean leaf beetle, may feed GEMENT occurrence of pest insects in soybeans. For example, on both foliage and pods but are primarily insects such as the Dectes stem borer and grape considered foliage feeders.
    [Show full text]
  • U.S. EPA, Pesticide Product Label, LAMBDA 13% INSECTICIDE, 04/24
    EPA Reg. Number: Date of Issuance: US. ENVIRONMENTAI.PR<lTECTION AGENCY 71532-20 Office of Pesticide Programs APR 2 4 20D7 Registration Division (H7505C) 1200 Pl:nnsylvania Avenue, N.W. Washington, D.c' 20460 NOTICE OF PESTICIDE: L Registration _ Reregistration (Under FrFRA as amended) Name LG Life Sciences, Ltd. c/o Biologic Inc. 115 Obtuse Hill Road and Rodenticide Act. Registration is in no way to bc construed as an endorsement or recommendation of this product by the Agency. In order to prot~t health and the : environment, the Administrator, on his motion, may at any time suspend or cancel the registratIOn of a pesticide in accordance with the Act. The acceptance , of any name in conneCtion with the registration of a product under this Act is not to be construed as giving the registrant a right to exclusive use of the name or to its use if it has been covered by others. This product is conditionally registercd in accordance with PIFRA sec. 3(c)(7)(A), subject to the following provisions: 1. You will submit andlor cite all data required for registration/reregistration of your pmduct under FIFRA sec. 3( c)(5) when the Agency requires all registrants of similar products to submit su;h data; and submit acceptable responses required for reregistration of your product under FIFRA sectior 4. 2. You will make the following label changes before you release the product for shipmmt: a) Revise the EPA Registration Number to read "EPA Reg. No.71532-20." b) Add "Contains petroleum distillates" immediately below the ingredient statement as a footnote below the term "Inert ingredients." c) Under First Aid list the statcments in the following order: "If on skin or clothing, Ifin eyes, If swallowed, If inhaled." d) Revise the 2"d bullet of the "If Swallowed" first aid statements to read "Do not give any liquid to the person." e) Add H(PPE)" after the Personal Protective Equipment headi!lg on page 3.
    [Show full text]
  • The Fall Armyworm – a Pest of Pasture and Hay
    The Fall Armyworm – A Pest of Pasture and Hay. Allen Knutson Extension Entomologist, Texas A&M AgriLife Extension Texas A&M AgriLife Research and Extension Center, Dallas, 2019 revision The fall armyworm, Spodoptera frugiperda, is a common pest of bermudagrass, sorghum, corn, wheat and rye grass and many other crops in north and central Texas. Larvae of fall armyworms are green, brown or black with white to yellowish lines running from head to tail. A distinct white line between the eyes forms an inverted “Y” pattern on the face. Four black spots aligned in a square on the top of the segment near the back end of the caterpillar are also characteristic. Armyworms are very small (less than 1/8 inch) at first, cause little plant damage and as a result often go unnoticed. Larvae feed for 2-3 weeks and full grown larvae are about 1 to 1 1/2 inches long. Given their immense appetite, great numbers, and marching ability, fall armyworms can damage entire fields or pastures in a few days. Once the armyworm larva completes feeding, it tunnels into the soil to a depth of about an inch and enters the pupal stage. The armyworm moth emerges from the pupa in about ten days and repeats the life cycle. The fall armyworm moth has a wingspan of about 1 1/2 inches. The front pair of wings is dark gray with an irregular pattern of light and dark areas. Moths are active at night when they feed on nectar and deposit egg masses. A single female can deposit up to 2000 eggs and there are four to five generations per year.
    [Show full text]
  • Fall Armyworm
    How to identify... Fall armyworm Fall armyworm or ‘American armyworm’ is a new pest in Africa that is currently attacking maize. This pest originates from the Americas, but it has recently been found in several countries in West and Southern Africa. This guide will help you to recognize fall armyworm and tell it apart from similar caterpillars such as other armyworms, stalk borers and cut worms. IDENTIFICATION Half-grown or fully grown caterpillars are the easiest to identify. Fall armyworm caterpillars have a characteristic pattern of dark pimples (spots) on their backs, each spot has a short bristle (hair). Although the skin looks rough it is smooth to the touch. Look out for four dark spots forming a square on the second to last segment (red circle). Each of the other body segments also has four spots, but they do not from a square pattern (yellow circle). The head is dark and shows a characteristic upside down Y-shaped pale marking on the front (blue circle). ©Russ Ottens, Bugwood.org ✔ ©Russ Ottens, Bugwood.org ✔ ©Russ Ottens, Bugwood.org ✔ Other armyworms, maize stem borer and cotton bollworm ©Donald Hobern, Denmark Hobern, ©Donald ✘ Denmark Hobern, ©Donald ✘ The cotton bollworm (Helicoverpa armigera) often shows a similar pattern of dots on its back, but its head is usually paler, and although they can also show an inverted Y this is usually a similar colour to the rest of the head. Unlike the fall armyworm they feel rough to the touch due to tiny spines. us Kloppers/PANNAR us ©Rik ✘ Bugwood.org Cranshaw, ©Whitney ✘ Flickr Reyes, Marquina ©David ✘ African armyworm Beet armyworm African cotton leafworm Spodoptera exempta Spodoptera exigua Spodoptera littoralis ©NBAIR ✘ CABI ©R.Reeder, ✘ Spotted stem borer African maize stalk borer Chilo partellus Busseola fusca Damage caused by Fall armyworm (Spodoptera frugiperda) ©J.
    [Show full text]
  • Overwintering Distribution of Fall Armyworm (Spodoptera Frugiperda) in Yunnan, China, and Influencing Environmental Factors
    insects Article Overwintering Distribution of Fall Armyworm (Spodoptera frugiperda) in Yunnan, China, and Influencing Environmental Factors Yanru Huang 1,2, Yingying Dong 1,2,*, Wenjiang Huang 1,2,* , Binyuan Ren 3, Qiaoyu Deng 4,5, Yue Shi 6, Jie Bai 2,7, Yu Ren 1,2 , Yun Geng 1,2 and Huiqin Ma 1 1 Key Laboratory of Digital Earth Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100094, China; [email protected] (Y.H.); [email protected] (Y.R.); [email protected] (Y.G.); [email protected] (H.M.) 2 University of Chinese Academy of Sciences, Beijing 100049, China; [email protected] 3 National Agricultural Technology Extension and Service Center, Beijing 100125, China; [email protected] 4 School of Geographic Sciences, East China Normal University, Shanghai 200241, China; [email protected] 5 Key Lab. of Geographic Information Science (Ministry of Education), School of Geographic Sciences, East China Normal University, Shanghai 200241, China 6 Department of Computing and Mathematics, Manchester Metropolitan University, Manchester M1 5GD, UK; [email protected] 7 State Key Laboratory of Remote Sensing Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100101, China * Correspondence: [email protected] (Y.D.); [email protected] (W.H.) Received: 8 October 2020; Accepted: 13 November 2020; Published: 15 November 2020 Simple Summary: The fall armyworm (Spodoptera frugiperda) is a nondiapausing insect pest capable of causing large reductions in the yield of crops, especially maize. Every year, the new generation of fall armyworms from Southeast Asia flies to East Asia via Yunnan, and some of them will grow, develop and reproduce in Yunnan since the geographical location and environmental conditions of Yunnan are very beneficial for the colonization of fall armyworms.
    [Show full text]
  • The Armyworm in New Brunswick
    ISBN 978-1-4605-1679-9 The Armyworm in New Brunswick Mythimna unipuncta (Haworth) Synonym: Pseudaletia unipuncta (Haworth) Family: Noctuidae - Owlet moths and underwings Importance The armyworm attacks mainly grasses. Crops attacked include: corn, forage grasses (timothy, fescues, etc.) and small grains such as oat, wheat, barley, rye and other small grains. Infestations in New Brunswick may be local or widespread and occur on irregular intervals, anywhere from 12 to 20 years. An outbreak occurs when local infestations become widespread. There have been a few reports when infestations have reoccurred at the same locations for a few years in a row in southern NB. Periodic outbreaks have caused widespread damage in southern and southwestern parts of the province. Life History In the spring, storm fronts carry these moths northward from the southern United States, or some moths may emerge locally in some areas of Canada. However, moths are seldom seen since they are active at night. Female moths lay eggs after 7 days and may lay up to 2000 eggs. Eggs are laid in clusters of 25 to 134 on grass or small grain leaves. Females live up to 17 days. Eggs are laid in folded leaves or leaf sheaths in early to late June and hatch in three weeks. In NB larvae appear from mid-June to the end of July. Larvae pass through 6 instars (the stage of development between successive moults) which takes 3 to 4 weeks. (A small percentage will develop to a 7th instar at low temperatures.) Larvae reach a length of 35 mm long when mature.
    [Show full text]
  • Spined Soldier Bug
    Beneficial Species Profile Photo credit: Russ Ottens, University of Georgia, Bugwood.org; Gerald J. Lenhard, Louisiana State University, Bugwood.org Common Name: Spined soldier bug Scientific Name: Podisus maculiventris Order and Family: Hemiptera; Pentatomidae Size and Appearance: Length (mm) Appearance Egg 1 mm Around the operculum (lid/covering) on the egg there are long projections; eggs laid in numbers of 17 -70 in oval masses; cream to black in color. Larva/Nymph 1.3 – 10 mm 1st and 2nd instars: black head and thorax; reddish abdomen; black dorsal and lateral plates. Younger instars are gregarious; cannibalistic. 3rd instar: black head and thorax; reddish abdomen with black, orange, and white bar-shaped and lateral markings 4th instar: similar to 3rd instar; wing pads noticeable 5th instar: prominent wing pads; mottled brown head and thorax; white or tan and black markings on abdomen. Adult 11 mm Spine on each shoulder; mottled brown body color; females larger than males; 2 blackish dots at the 3rd apical (tip) of each hind femur; 1-3 generations a year. Pupa (if applicable) Type of feeder (Chewing, sucking, etc.): Nymph and adult: Piercing-sucking Host/s: Spined soldier bugs are predators and feed on many species of insects including the larval stage of beetles and moths. These insects are found on many different crops including alfalfa, soybeans, and fruit. Some important pest insect larvae prey include Mexican bean beetle larvae, European corn borer, imported cabbageworm, fall armyworm, corn earworm, and Colorado potato beetle larvae. If there is not enough prey, the spined soldier bug may feed on plant juices, but this does not damage the plant.
    [Show full text]
  • Fall Armyworm Field Handbook Identification and Management FAO and CABI (2019) Fall Armyworm Field Handbook: Identification and Management, First Edition
    Fall Armyworm Field Handbook Identification and Management FAO and CABI (2019) Fall Armyworm Field Handbook: Identification and Management, First Edition. Cover Photo: Fall armyworm larva ©Georg Goergen, IITA This field handbook is an adapted version of FAO and CABI (2019) Community-Based Fall Armyworm (Spodoptera frugiperda) Monitoring, Early warning and Management, Training of Trainers Manual, First Edition. Licence: CC BY-NC-SA 3.0 IGO. It is intended to help extension workers and farmers in the field to identify fall armyworm and know how to manage it. The Training of Trainers Manual was funded by US Foreign Disaster Assistance, Bureau for Democracy, Conflict and Humanitarian Assistance, US Agency for International Development (USAID). The editing and printing of this handbook was made possible with the kind financial support of the Netherlands Directorate General for International Cooperation (DGIS). The author’s views expressed in this publication do not necessarily reflect the views and policies of FAO, CABI, USAID, UKAID or DGIS. © FAO and CABI, 2019 Further information Fall armyworm portal: www.cabi.org/fallarmyworm Fall armyworm FAO: www.fao.org/fall-armyworm/en Contents How to identify fall armyworm ........................................... 4 How to monitor fall armyworm in the field ....................... 19 How to manage fall armyworm ....................................... 25 Find out more................................................................... 36 4 FALL ARMYWORM FIELD HANDBOOK IDENTIFICATION AND MANAGEMENT How to identify fall armyworm Fall armyworm larvae (or caterpillars) are similar to caterpillars of other related pests (Figure 1). Look for the following features to determine if the caterpillar you have found in your maize is fall armyworm or belongs to another species. • A dark head with a pale, upside-down Y-shaped marking (Figure 2, black circle).
    [Show full text]
  • E0020 Common Beneficial Arthropods Found in Field Crops
    Common Beneficial Arthropods Found in Field Crops There are hundreds of species of insects and spi- mon in fields that have not been sprayed for ders that attack arthropod pests found in cotton, pests. When scouting, be aware that assassin bugs corn, soybeans, and other field crops. This publi- can deliver a painful bite. cation presents a few common and representative examples. With few exceptions, these beneficial Description and Biology arthropods are native and common in the south- The most common species of assassin bugs ern United States. The cumulative value of insect found in row crops (e.g., Zelus species) are one- predators and parasitoids should not be underes- half to three-fourths of an inch long and have an timated, and this publication does not address elongate head that is often cocked slightly important diseases that also attack insect and upward. A long beak originates from the front of mite pests. Without biological control, many pest the head and curves under the body. Most range populations would routinely reach epidemic lev- in color from light brownish-green to dark els in field crops. Insecticide applications typical- brown. Periodically, the adult female lays cylin- ly reduce populations of beneficial insects, often drical brown eggs in clusters. Nymphs are wing- resulting in secondary pest outbreaks. For this less and smaller than adults but otherwise simi- reason, you should use insecticides only when lar in appearance. Assassin bugs can easily be pest populations cannot be controlled with natu- confused with damsel bugs, but damsel bugs are ral and biological control agents.
    [Show full text]
  • Fall Armyworm: Impacts and Implications for Africa Evidence Note Update, October 2018
    Fall armyworm: impacts and implications for Africa Evidence Note Update, October 2018 Rwomushana, I., Bateman, M., Beale, T., Beseh, P., Cameron, K., Chiluba, M., Clottey, V., Davis, T., Day, R., Early, R., Godwin, J., Gonzalez-Moreno, P., Kansiime, M., Kenis, M., Makale, F., Mugambi, I., Murphy, S., Nunda. W., Phiri, N., Pratt, C., Tambo, J. KNOWLEDGE FOR LIFE Executive Summary This Evidence Note provides new evidence on the distribution and impact of FAW in Africa, summarises research and development on control methods, and makes recommendations for sustainable management of the pest. FAW biology FAW populations in Africa include both the ‘corn strain’ and the ‘rice strain’. In Africa almost all major damage has been recorded on maize. FAW has been reported from numerous other crops in Africa but usually there is little or no damage. At the moment managing the pest in maize remains the overriding priority. In Africa FAW breeds continuously where host plants are available throughout the year, but is capable of migrating long distances so also causes damage in seasonally suitable environments. There is little evidence on the relative frequency of these two scenarios. Studies show that natural enemies (predators and parasitoids) in Africa have “discovered” FAW, and in some places high levels of parasitism have already been found. Distribution and Spread FAW in Africa Rapid spread has continued and now 44 countries in Africa are affected. There are no reports from North Africa, but FAW has reached the Indian Ocean islands including Madagascar. Environmental suitability modelling suggests almost all areas suitable for FAW in sub-Saharan Africa are now infested.
    [Show full text]
  • Corn Earworm, Helicoverpa Zea (Boddie) (Lepidoptera: Noctuidae)1 John L
    EENY-145 Corn Earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae)1 John L. Capinera2 Distribution California; and perhaps seven in southern Florida and southern Texas. The life cycle can be completed in about 30 Corn earworm is found throughout North America except days. for northern Canada and Alaska. In the eastern United States, corn earworm does not normally overwinter suc- Egg cessfully in the northern states. It is known to survive as far north as about 40 degrees north latitude, or about Kansas, Eggs are deposited singly, usually on leaf hairs and corn Ohio, Virginia, and southern New Jersey, depending on the silk. The egg is pale green when first deposited, becoming severity of winter weather. However, it is highly dispersive, yellowish and then gray with time. The shape varies from and routinely spreads from southern states into northern slightly dome-shaped to a flattened sphere, and measures states and Canada. Thus, areas have overwintering, both about 0.5 to 0.6 mm in diameter and 0.5 mm in height. overwintering and immigrant, or immigrant populations, Fecundity ranges from 500 to 3000 eggs per female. The depending on location and weather. In the relatively mild eggs hatch in about three to four days. Pacific Northwest, corn earworm can overwinter at least as far north as southern Washington. Larva Upon hatching, larvae wander about the plant until they Life Cycle and Description encounter a suitable feeding site, normally the reproductive structure of the plant. Young larvae are not cannibalistic, so This species is active throughout the year in tropical and several larvae may feed together initially.
    [Show full text]
  • The Physiology of Cold Hardiness in Terrestrial Arthropods*
    REVIEW Eur. J. Entomol. 96: 1-10, 1999 ISSN 1210-5759 The physiology of cold hardiness in terrestrial arthropods* L auritz S0MME University of Oslo, Department of Biology, P.O. Box 1050 Blindern, N-0316 Oslo, Norway; e-mail: [email protected] Key words. Terrestrial arthropods, cold hardiness, ice nucleating agents, cryoprotectant substances, thermal hysteresis proteins, desiccation, anaerobiosis Abstract. Insects and other terrestrial arthropods are widely distributed in temperate and polar regions and overwinter in a variety of habitats. Some species are exposed to very low ambient temperatures, while others are protected by plant litter and snow. As may be expected from the enormous diversity of terrestrial arthropods, many different overwintering strategies have evolved. Time is an im­ portant factor. Temperate and polar species are able to survive extended periods at freezing temperatures, while summer adapted species and tropical species may be killed by short periods even above the freezing point. Some insects survive extracellular ice formation, while most species, as well as all spiders, mites and springtails are freeze intoler­ ant and depend on supercooling to survive. Both the degree of freeze tolerance and supercooling increase by the accumulation of low molecular weight cryoprotectant substances, e.g. glycerol. Thermal hysteresis proteins (antifreeze proteins) stabilise the supercooled state of insects and may prevent the inoculation of ice from outside through the cuticle. Recently, the amino acid sequences of these proteins have been revealed. Due to potent ice nucleating agents in the haemolymph most freeze tolerant insects freeze at relatively high temperatures, thus preventing harmful effects of intracellular freezing.
    [Show full text]