Fd5359df95mannual ENT 4121.Pdf

Phone : 01425-254022, (O) 01425-254022 (Fax) Dr. G.L. Keshwa

February 22, 2010

I am really glad to know that the Practical Mannual for Insect Morphology and Systematic has been prepared for B.S.c. Ag. Hons. Part-I students by Dr. M.C. Bhargava and Dr. Ashok Sharma, Department of Entomology. The practical manual will fulfill the need and necessity of Introductory Entomology and will provide the guidelines for the students. I congratulate the authors in bringing out this publication and wish them all the success in their future eneavour.

PREFECE

The main aim of preparing this practical manual is to provide the undergraduate students of Agriculture, a simple exposition of the subject. It is primarily designed to cover the syllabus of Insect Morphology and Systematics (Ento-

4121). The manual contains details about introductory entomology including external and internal anatomy of grasshopper and classification of orders of agriculture importance up to family level.

We feel immense pleasure in expressing our heartfelt regards with deep sense of gratitude to Dr. G L Keshwa, Dean, SKN College of Agriculture, Jobner for giving inspiration to prepare this manual.

Place Jobner M.C. Bhargava

Date ...... Ashok Sharma

Ento 4121 INSECT MORPHOLOGY AND SYSTEMATICS 3(2+1)

CONTENTS S. No. Exercise Date Remark 1. Observing and sketching of external structure of grasshopper ...... 2. Acquaintance with the insect collection material ...... 3. Pinning of different type of insects and ...... preservation of different stages of insects 4. Preparation of temporary mount of biting and ...... chewing type of mouth parts. 5. Preparation of temporary mount of sponging and ...... chewing and lapping type of mouthparts 6. Preparation of temporary mount of piercing and ...... sucking type of mouthparts 7. Mounting of different types of antennae ...... 8. Mounting of different types of legs ...... 9. Observing different types of wings, modification ...... and wing coupling apparatus 10. Dissection of grasshopper/cockroach to expose ...... digestive and nervous system 11. Dissection of grasshopper/cockroach to expose ...... reproductive organ. 12. Observing the characters of order Orthoptera and ...... Isoptera and its families of Agriculture importance 13. Observing the characters of order Lepidoptera ...... and Thysanoptera and its families of Agriculture importance 14. Hymenoptera and its families of Agriculture ...... importance 15. Observing the characters of order Coleoptera ...... and its families of Agriculture importance 16. Observing the characters of order Diptera and ...... its families of Agriculture importance

Exercise No. - 1 OBSERVING AND SKETCHING OF EXTERNAL STRUCTURE OF GRASSHOPPER

The super class Hexapod has three distinct body divisions viz., head, thorax and abdomens, normally with a pair of antennae, a pair of compound eyes, a pair of mandibles, two pairs of wings and abdomen with no locomotory appendages. They are tracheal arthropods. Body covered with a chitinous exoskeleton. 1. Head Depending on the orientation of the head, insect head are categorized in to three types viz., Prognathous, Hypognathous and opisthognathous. In grasshopper the head is hypognathus since the mouthparts are at right angle to body axis. Sutures and area of head 1. Frons: Is is an area on the anterior face lies below the vertex and extent from frontal suture to clypeus and up to the base of both the mandibles. 2. Clypeus: It is a lip like area frontal suture, which lies above frons. The ocelli and antennae are situated in this region. 3. Vertex: The part above the frontal suture, which lies above frons. The ocelli and antennae are situated in this region. 4. Epicranial suture: The inverted „Y‟ shape structure lies between the eyes. 5. Genae: Lateral walls of the head situated below the eyes. 6. Post genae: The area directly posterior to the eyes. 7. Commound eyes: Paired structure situated dorsoventrally. 8. Ocelli: Located between the compound eyes generally three in number. 9. Tentorium: The endoskeleton of the head. 10. Ocular sclerite: compound eye is surrounded by a narrow ring like structure known as ocular sclerite. 11. Occiput: Hinder part of the head region. Appendages of head Antennae: The paired segmented sensory organs are born one on either side of the head. A typical antenna consists of three regions, the scape, the pedicle and the flagellum. Mouthparts: Typically insect mouthparts consist of the labrum or upper lip, the labium or the lower lip, a pair of mandibles or the upper pair of jaws, a pair of maxillae or the lower pair of jaws and a median fleshy tongue like roof. In grasshopper the mouthparts are of the mandibulate or biting and chewing type. Labrum: The labrum is a flap like structure attached to the clypeus bearing many sensilla and is known as „epipharynx‟. Mandibles: A pair of maxillae is located behind the labrum adapted for cutting or crushing the food. It is movable by mean of two powerful muscles, the adductor and adductor muscles. Maxillae: A pair of maxillae is located behind the mandibles. The maxillae are used for holding the foods. Each maxilla composed of following segments. (a) Cardo: Triangular, basal part. (b) Stipes: Rectangular, central part. (c) Galea: It is the outer lobe. (d) Lacinia: It is the inner lobe. (e) Maxillary palp: Antennae like appendages attached with the both sides of the stipes. Labium : The unpaired labium consists of two plates, the mentum and prementum. The post mentum is divided into sub mentum and mentum, connected to the prementum. Two pairs of lobes, the glossa and paraglossa and a pair of lateral labial palpi with up to three segments are attached to the pre mentum. Hypopharynx: It is a tongue like structure arising from the floor of the mouth cavity. The salivary glands open through it.

2. Thorax It is the second of the insect body bearing three pairs of legs and two pairs of wings, when present. It consists of three segments, the prothorax, the mesothorax and the metathorax. The flexible inter segment region between the head and prothorax is known as the cervix or the neck region. Each thoracic segment of an insect is typically made up of four sides, the dorsal notum, the ventral sternum and the two lateral pleura. Thoracic appendages Legs: Each of the thoracic segment bears a pair of legs located on the ventral surface. Typically each leg consists of six parts, coxa, trochanter, femur, tibia, tarsus and pretarsus. Wings: Typically, adult insect have two pairs of wings. However, there may be reduction in the number of wing to one pair as in Diptera. Primitive insects lack wings. Insect‟s wings are broadly triangular and three sides and three angles could be seen. Three margins: Anterior margin (costal margin), outer or the apical margin and the inner or anal margin. Three angles: Humeral angle, apex angle and anal angle. 3. Abdomen Posterior region of the insect body typically consists of 10-11 segments, but the number varies in different insects. In grasshopper 11 segments are present. In both the sexes a pair of podical plates and a pair of cerci present. In males a pair of style are present along with the cerci. Anal opening is present on the 10th segment. The genitalia opening are ventrally on the 8th in female and between 8th and 9th segments in male. Exercise No. -2

ACQUAINTANCE WITH THE INSECT COLLECTION MATERIAL

The equipments required for collecting insects includes; insect net, killing bottle, collection box, vials for preservation, forceps, aspirator, knife for open galls and bark and insect pins. Insect net An insect net consists of a handled fitted with a wire ring to which a cloth bag is attached. The aerial net is used to collecting insects such as butterflies, dragonflies and wasps, It should be light in weight and provided with mosquito netting bag. The length of the bag should be about twice the diameter of the ring. Care and use Flowers and other parts should be swept with a side vise motion. This will collect more insects then upward and downward sweep. Short stroke are more effective than long stroke. Killing bottle When an insect has been collected, it should be killed as quickly as possible in a killing bottle to avoid damaging the specimen. Any wide mouth bottle be used for preparing a killing bottle. How to prepare a killing bottle Several chemicals are available for use killing agent in the bottle. Ethyl acetate and cyanide are the most satisfactory. Chloroform and carbon tetrachloride may be used as substitute killing agent when the other compounds are not available. The best killing bottle is made by potassium cyanide, sodium cyanide and calcium cyanide. These compounds give a concentration of deadly fumes sufficient to kill most insects in short time. The bottle is charged by filling a small lump of potassium cyanide and then filling the chinks between the lumps with dry plaster of paris is now made up with a minimum of water and poured over the cyanide to form a smooth layer which sets hard and keep it in place. Then it should be covered with a thick layer of white blotting paper. Cyanide is a deadly poison and must be handle with extremely care. Bottle containing cyanide should be labeled with “POISON”. The insects should be removed from the bottle as soon as the insect dies.

Exercise No. - 3

PINNING OF DIFFERENT TYPES OF INSECTS AND PRESERVATION OF DIFFERENT STAGES OF INSECTS

After specimen are collected they must be preserved for future study. Larvae and soft- bodied insects may be preserved in 70 percent alcohol or 4 percent formaldehyde solution. Caterpillars, grubs and maggots should first be heated 5 of 10 minutes in water just at boiling point. This treatment sterilized the specimen and prevents discolouration by bacteria in the digestive tract. Most hard bodied insects are mounted on pins. Pinning insects Insect‟s pins are made in various sizes and various materials. They should be made of a hard, non corrosive metal, have sharp point and small heads and suitable length. Generally pure nickel pins sizes 16 and 20, which are 35mm and 15mm long are used for large and small insects. These two sizes of pins are suitable for all general collecting purpose. They can be obtained from any entomological supplier. Insects are pinned vertically through a body place where the pin is inserted depends up on the type of insect. The following rules are followed in pinning the different groups of insects. 1. Orthoptera (grasshopper, crickets, locust etc.) Pin through the back of the promoting, slightly to the right of the middle line. 2. Hemiptera (bugs etc) pin through the scutellum, slightly to the right to the middle line. 3. Coleoptera (beetles) pin through right elytra (wing cover) about mid way of the body. 4. Lepidoptera (butterflies and moths) insert the pin between the bases of the front wing. 5. Diptera (flies) and Hymenoptera (bees and wasps etc.) Pin through the thorax slightly to the right of the middle line. 6. Odonata (dragonflies) pin through the middle of the thorax. A collection should be appearing neat with the specimen uniformly mounted. It is well to have all insects the same distance from the top of the pin should be uniformly arranged. Setting Boards Some insects such as moths and butterflies are usually mounted with their wings spread. To do this well it is necessary to have setting boards that are accurately made. It is usually made of parallel stripes of wood covered with prepared cork sheet and space between to receive the bodies of the insects. The specimen to be set is first pinned through its upper work of the board and in to the cork on the base. Insert the insect body in the groove so that the wing bases are in level with the near edge of the top pieces. Hold the wings at the top level by two narrow strips of paper and put them forward until the hind margin of the front wing is at right angle to the body axis and the front margin of the hind wing is just under the front wing. When wings of the both the sides of the insect are thus adjusted lay strong piece of paper over them and pin them don securely with large pins, inserted close to the wings but not through them. Put the specimen in a dry pest proof container or room 2 or 3 weeks. It will then have set sufficiently to be removed the board. Labeling specimen Unless a specimen in a collection is accompanied by a label bearing certain essential information it is of little scientific value. A label should always give the data and locality of the insect capture. Additional information giving the name or initials of the collection and host or habitat of the insect is desirable. One or two labels may be used. If only one label is used it should bear the locality, date and name or initials of the collector. When two labels are used the first should give information of locality and date, and second the name of collector and hosts and habitat. Name of the specimen can be given if identified. Label should be of uniform size about 3/4 inch long and 1/4 inch wide and made from stuff paper. Lettering may be done by hand or printed. The label should be as small as and should run about half way up to the pin, but not too near the specimen and they should project from the pin in the same direction as the specimen. Insect boxes Boxes are used for the temporary or permanent preservation of pinned specimens. The box should be light and airtight lined with some material, which will hold the pins firmly and convenient size and weight for storage and handling. The most convenient external dimensions 17.5 inch long, 12 inch broad and 4 inch deep. Lined on both sides with cork covered with white paper and provided with a naphthalene cell. Protecting collection from pests One of the worst enemies of the insect collection in India is mould. It is often difficult to avoid mould developing on newly caught and imperfectly dried specimen especially when collecting in damp climate and having to open the collection box constantly to add fresh specimens. Before keeping specimens it is desirable to treat the insect box with a saturated solution of naphthalene in benzene. Then naphthalene tablets should be kept in cells of the boxes to avoid the infection of the pests.

Exercise No. - 4

PREPARATION OF TEMPORARY MOUNT OF BITING AND CHEWING TYPE OF MOUTHPARTS

Mouthparts Typically insect mouthparts consist of the labrum or the upper lip, the labium or the lower lip, a pair of mandibles of the upper pair of jaws, and a median tongue like structure or hypopharynx, which arises from the floor of the mouth. Depending on the shape and function, the mouthparts of insects are classified into several types. In grasshoppers the mouthparts are of mandibulate or the biting and chewing or the orthopteroid type. The labrum of the upper lip: A rectangular plate hinged to clypeus capable of limited up and down movement. It represents the most anterior region of the head. Upper surface of labrum is hard while the surface is soft and is lined with a median lobe having sensilla known as „epipharynx‟. Labrum is articulated by two lateral sclerites, called format to the clypeus. A pair of anterior median muscles keeps away labrum from mandibles and a pair of laterally arising posterior muscles keep labrum intact. The mandibles: A pair of true jaws adopted for cutting or crushing the food. Each is a compact solid cone shaped piece articulating with the head by means of a condyle and ginglymus. It is movable by means of two powerful muscles, the adductor and abductor muscles. A long the biting margin, bluntly toothed molar area or crushing surface and sharp teethed incisor area are present. Location of teeth is asymmetrical. The Maxillae: Each maxilla is composed of the following segments (1) the cardo is the first proximal piece which is directly attached to the head. (2) the stipes articulates with the distal border of the cardo and bears laterally the maxillary palpi, which are 5 segmented in grasshoppers. Distally the stipes bears two lobes, the outer galea and the inner lacinia. The labium : The labium consist of a plate composed of a proximal postentum which is often divided in to submentum, a middle mentum and a distal premmentum bearing two pairs of lobes, the glossa and paraglossa and a pair of labial palpi laterally which are three segmented. Labium appears like fused secondary maxillae. The hyopoharynx or the tongue : A medioventral lobe it occupies the space between the mandibles dorsally, the labium ventrally and the maxillae laterally. In the midline on its ventral side is the aperture of the salivary duct and on dorsal side is the mouth. Tongue is partially sclerotized and remaining is soft, these sclerites which give attachment to muscles called as ligual sclerites. Directions: Hold the head firmly, dorsally, across the axis between the thumb and index finger of your left hand so that the mandibles and labrum are left free for dissection. Locate the labrum and mandibular bases with the help of a needle in right hand. Take fine forceps in right hand and pull out labrum holding firmly at the base and place it in a drop of a glycerin on the slide. In the same manner pull out the mandibles one after another holding firmly at the base and place them in a glycerin drop. Turn the head ventrally and this time holds the head all along the axis in left hand firmly in such a way that you will be able to see the maxilla completely. With the help of a needle in your right hand, locate the base of the cardo. Take forceps in right hand and insert it at the base of the cardo and pull out holding firmly. Place the maxilla on glycerin drop on the slide. Hold the hand firmly along the axis in opposite direction so that you can see other maxilla freely. Locate the base of the cardo of other maxilla again and then with the help of forceps remove the maxilla and place it in the glycerin drop. Hold the ventral aspect of the head between your first three fingers of left hand in such a way that you can see the entire labium. Acquaint with all parts of the labium with the help of needle in your right hand. Insert the tip of the needle in your right hand right at the base of labium and roll the needle towards the anterior side of the head so that hypopharynx (tongue) is separated from the labium. Hold the base of labium firmly with the forceps in your right hand and pull and place it in the glycerin drop on the slide. Remove the hypopharynx left in the head with the help of forceps. Often, when you pull the tongue along with it a part of oesophagus also comes out. Cut the esophagus with the help of scissors. Arrange the parts as instructed by the teacher in the glycerin drop on the slide. Draw a near diagram and label all the parts.

Exercise No. - 5 PREPARATION OF TEMPORARY MOUNT OF SPONGING AND CHEWING AND LAPPING TYPE OF MOUTHPARTS

Sponging type of mouthparts Mandibles are absent; labrum reduced. Mouthparts are of sponging and sucking type. The labium is modified in to a proboscis. The proboscis has two parts. A conceald basal portion or the rostrum and a distal haustellum. The rostrum caries anteriorly the maxillary palp. The haustellum carries the labrum and hypopharynx, and distally it expands to form a pair of fleshy lobes of labella. The membrane investing the oral or distal surface of the labella contains a series of food canals or pseudotracheae, which pass from its outer edges to the inner margins. The proboscis is adopted for sucking by wetting the substance by saliva and than sponging and sucking. Directions: Separate the head from the thorax and remove the antennae. The separated head is boiled with KOH solution in the test tube for 2 minutes. After removing the head from the test tubes and taken out on slide and press gently with the help of another slide to stretched properly on a slide to show the various parts. Sketch and label the parts. Chewing and lapping type of mouthparts Mouthparts are for chewing and lapping. Labrum narrow mandibles space like maxillae are modified. The cardo is stalk like and narrow. At its distal end is the stipes, which forms the chief basal plate of the maxilla. At the apex of the stipes on the outer border is a minute peg like two-segmented maxillary palp. The galea is large blade like lob articulating with distal extremity of the stipes the lacinia are reduced. In the labium, prementum is large and sclerotized. It articulates with a small triangular sclerite on the mentum. A flexible transverse band, one end of which supports the mentum, respresents the sub mentum and the other is attached to the cardo. The labial palpi are conspicuous and 4 segmented. The paraglossae are represented by two small concealed lobes at the distal end of the pre mentum. The elongated glossa is hairy and is a small spoon shaped lobed flabellum. The side wall meet along the mid ventral region to form an imperfect tube. When at rest, the mouthparts are folded down beneath the head against the stipes and mentum are straightened while feeding. Directions: Separate the head from the thorax and remove the antennae and mouthparts. The mouthparts except the labrum and the mandibles need not to separated. After removing the mandibles and the labrum the whole mouthparts may be taken out of the head and stretched properly on a slide to show the various parts. Arrange the labrum and the mandibles in their respective positions along with the rest of the mouthparts on a slide. Sketch and label the parts. Exercise No. - 6

PREPARATION TEMPORARY MOUNT OF PIERCING AND SUCKING TYPE OF MOUTHPARTS

Plant bug In plant bugs the mouthparts are of piercing and sucking type. The mandibles and maxillae are modified in to needle like structures for piercing and sucking. The labrum is narrow triangular and elongated, forming an upper covering of the rostrum. The labium is elongated and four segmented forming a rostrum in which the stylets are lodged. The mandibular stylets are used for piercing and maxillary stylets are used for sucking. Mosquitoes Mouthparts are modified for piercing and sucking. The mandibles and maxillae, the labrum epipharynx and hypopharynx are all modified in to elongated needle like structures of stylates. All the stylates are lodged in a sheath like rostrum, which is the modified labium. A pair of three segmented maxillary palpi is present. Directions: Separated the head from the thorax, remove the antennae, keep the head dorsoventrally on the slide and straighten the rostrum and gently tap t the base of the rostrum with the help of a needle to separate the stylates. The mandibular stylates by the presence of serrated apex. Prepare a temporary mount showing four stylates, the labrum and the rostrum. Sketch and label the parts.

Exercise No. - 7

MOUNTING OF DIFFERENT TYPES OF ANTENNAE

Antennae The antennae of insects are usually located between or below the compound eyes. They are articulate in the antennae socket, which is surround by narrow ring like antennal sclerite. They are sensory in function and act as a organ for feeding, smelling and in some cases hearing. In the more specialized insect antennae is divisible into scape, pedicle and flagellum. 1. Scape: It is the first or basel segment of the antennae and is often conspicuously longer than any of the succeeding segment. 2. Pedicle: It is the segment which immediately follow the scape. It forms a pivot between the scape and flagellum in the geniculate antennae. 3. Flagellum: The flagellum forms the reminder of the antennae. It varies greatly in its form in adoption to the particular surrounding and habit of the species concerned. Study and identify the different types of antennae The antennae of insects vary greatly in size and form and much used in the classification. Depending on the shape, size and length of segments several types of antennae are recognized in insects. In this exercise you sill study the following types. 1. Filiform: Thread like, the segments nearly uniform thickness and imperceptibly reduce towards the distal end and there are no prominent constrictions at the joints. Example order Orthoptera, ground beetle. 2. Moniliform: Necklace form, the segment similar in size and spherical in shape Example: order Isoptera (termite) 3. Setaceous: Bristle like, flagellate segmental antennae. Antennae decrease in size from base towards apex. Example: cockroach, some insects of order Coleoptera and Lepidoptera 4. Serrate: Saw like, the segments are more or less triangular, projecting in one direction lake the teeth of a saw. Example: order Coleoptera 5. Pectinate: Comb like, the segments have long processes only on one side which appear like the teeth of a comb. Example: order Coleoptera 6. Bipectinate: This antenna differ from the pectinate antennae in having the long projections on two side. Example: order Lepidoptera 7. Clavate: Club shaped, the flagella segment gradually increase in size towards apex. Example: order Coleoptera and Lepidoptera (butterflies) 8. Capitate: With a head, the terminal segment becoming suddenly enlarged in size. Example: chalcids, butterflies, meloid beetles etc. 9. Lamellate: Leaf like, the terminal segment expending laterally to form rounded or over leaf like lobes. Example: dung beetle 10. Aristate: The antennae is made up of three segments, bear a heavy bristle known as arista. Example: family Musidae of order Diptera (flowerfly) 11. Stylate: The last segment of the antennae has a bristle, known as style at the end. Example: family Asilidae of order Diptera (robberflies) 12. Geniculate: The antennae bends abruptly at an angle at the distal end of scape like a bent knee. This is always help in this position by the insect. 13. Plummose: The whorl of hairs are coming off from each joint end and thus the antennae appears like plumose. Example: order Diptera 14. Whorled: There is a whorl of bristles at every node. Example: order Hemiptera (male of mango mealy bug) 15. Flabellate: There is a special apparatus known as flabella in which the flagellum seems to be lodged. Example: order Strepsitera

Exercise No. - 8

MOUNTING OF DIFFERENT TYPES OF LEGS

Leg is a characteristic single in insect, which is jointed. It is present in adult and all stages. Three pairs of legs are present on the three thoracic segments respectively, known as prothoracic (fore), mesothoracic (middle) and metathoracic (hind) legs. The legs are primarily organ for running or walking but may undergo some modification according to the use of the insect. Parts of a typical leg Leg has five true independently movable segments: coax, trochanter, femur, tibia and tarsus. The coxa, femur and tibia are always unsegmented; the trochanter is usually one segmented except in parasitic wasp. Tarsus is composed of a number of segments. Coxa: It is a basel segment, which articulates with the body. It fits in cup like depression of the body and is freely movable. Trochanter: It is a small segment following coxa and second segment. It articulates with coxa but fixed with femur. Femur: It is third segment of the leg, cylindrical, strongest part of the limp and moves along with trochanter. Tibia: It is fourth segment, equal or slightly longer but slender than the femur. The distal end bears 1-2 tibial spur. Tarsus: It forms distal part of the leg and made-up of series of small movable segments called tarsomer (2-5 segments). The terminal segment is called pretarsus which bears a pair of claw and pad like structure between or at the base of claw. If the pad is between the claws, it is called Arolium and if it is at the base of claw it is called Pulvilli. When arolium is represented by a slender bristle like structure, it is called Empodium. Modification of legs In genera, insects have simple legs designed for walking and running. However, in some insects the legs are modified for different purposes. The chief modification of the insect legs are described below: 1. Walking or Ambulatorial leg It is the simplest form of the insect leg adopted for walking. All the five parts of leg are normally developed. Example: cockroach 2. Running or Cursorial leg In this tarsus is comparatively longer which touches the ground for its entire length. The trochanter is two segmented. Example: Ichneumon wasp.

3. Digging or fossorial leg This leg is modified for digging purposes. It is exceptionally powerful, broad and small in size. The coxa, trochanter and femur are very strong and broad, while tibia is provided with four strong scrapers like prolongations at its broad distal end, which are utilized, for digging the ground or even cutting the roots of the plants. The tarsus is composed of 2-3 segments, each segment projecting like a tooth and helps the tibia in digging. Example: fore of leg of mole cricket. 4. Preying or Grasping or Raptorial leg This leg is highly modified for catching prey. The coxa is elongated and mobile while femur is thickly spinose and grooved along their lower side. The tibia is also spinose and fits in to the groove along the femur. The prey thus firmly help between the grooves and is killed by the spinose femur and tibia. The tarsus is reduced and is composed of five segments. Example: fore legs of preying mantis. 5. Pollen collecting of Foragial leg The posterior pair of legs of honeybee is adopted for pollen collection. The coxa, trochanter and femur are normal. Modification takes place in tibia and tarsus. The posterior tibia is more or less dilated and margined with long hairs thus modified to form pollen basket. The basis tarsus (first tarsus segment) is flattened on it inner aspect and provided with the several rows of short stiff spines which form a brush. This brush helps the bees in gathering the pollen adhering to the hairs of its body. Example : hind leg of worker honeybee. 6. Swimming or Natatorial leg The insects living in water are provided with such legs. The femur, tibia and tarsus are flattened and are provided with long rows of hairs. Such long brushes of hairs help the insect in swimming in the water. Example: hind leg of dytiscus. (Predacious diving beetle) 7. Clinning or Scansorial leg The coxa is widely separated and 1-2 segmented tarsi bear a single claw. This claw along with the tarsus is closely approximated to the tibial end by the muscular action and thus allows the insect to maintain a firm attachment with the hairs of the host. Example: louse, fore leg of bug. 8. Jumping or Saltatorial leg The femur i greatly enlarged and accommodates the accommodates the powerful tibia levator muscles. By contraction of these muscles, the body of insect is thrown in to the air and by repeating this action the insect moves in the desired direction. Example: hind leg of grasshopper. 9. Sound producing or Stridulatorial leg The hind leg of male grasshopper is provided with a row of pegs on the inner side of each femur, which works against the outer surface of each tegmen to produce sound. Example: hind leg of male grasshopper. 10. Sticking leg A pair of pad likes structure known as pulvilli are present at the base of claws provided with numerous hollow and tubular hairs, which exude a sticky substance. A bristle like structure known as empodium is present in between the pulvilli. This modification enables the fly to walk even on a very smooth surface. Example: Housefly 11. Suctorial leg The coxa and trochanter are very small, femur is thick and small, tibia is small and flat. The tarsus is five segmented on which hairs present are used for swimming. The first three segments of tarsus are modified in to a bloom like stricture. On the first segment two vacuum cups, which are used for copulating female at the time of mating and helps in sticking to grasses in opposite direction of flowing water. Example: fore leg of male dytiscus. Prolegs In caterpillars, in addition to the three pairs of jointed legs on the thorax any where from 2-8 abdominal pairs of fleshy unjointed projections of the abdomen which are used as legs and are known as prolegs.

Exercise No. - 9

OBSERVING DIFFERENT TYPES OF WINGS, MODIFICATION AND WING COUPLING APPARATUS

Insects are only the animals possessing true wings, which constitute the characteristics feature of the class Insecta. The power of flight has given them are obvious advantage and has helped them to dominate the animal kingdom. Generally there are two pairs of wings, which are the out growth of the body wall along the lateral margin of the thorax. However, in certain insect orders (Thysanura, Protura, Diplura and Collembola) they are altogether absent which is a primitive character of Apterygota (wingless), while in order Diptera there is only one pair of wing and the hind pair of wing is modified in to halter. In some Pterygote insects like ants, termites, bed bugs and head louse the loss of wings is a secondary acquired character. The name of most of Pterygote orders have also been derive on the basis of nature of wings, for instance, orthoptera (straight+wings), isoptera (equal+wings), lepidoptera (scale+wings), coleoptera (sheath+wings), hymenoptera (membranous+wings) and diptera (twice+wings) etc. Wings margin, angles and their regions A generalized insect wing is more or less triangular membranous flap, strength by number of veins arising from its narrow base and running towards the outer margin. The wings have the three margins the anterior margin or costa, the outer or apical margin and the inner or anal margin. Besides, these well-demarcated angles are also distinguishable, viz., the humeral angle at the base of costa; the apical angle between the costa and outer or apical margin and the anal angle or tormus between the outer and inner margin. A typical wing consists of the following regions. 1. Axillary region: The area is located at the base of the wings. The axillary sclerite is also situated in the same region. 2. Remigium: this is anterior stiff of hard position of the wings, which is separated by the ventral fold from the flexible region of the wings. 3. Vannus: This region lies between the jugal and the venal fold. 4. Jugum: This is a lobular region situated near the jugel and the ventral region. Modifications of the wings The insect wings are highly modified in to various forms. 1. Tegmina: This condition is found in the fore wings of order orhtoptera, dictyoptera and Phasmidia where they harden and leathery in consistency. 2. Elytra: In insects of order coleoptera and dermapters the fore wing yet much harden to form hardy sheath which protect the membranous hind wings. 3. Hemielytra: This is well illustrated in hymenoptera insects where in the fore wing are thickened and their bases like elytra and remaining as soft or membranous, that is why they are frequently termed as hemelytra. 4. Halters: The hind wings of diptera are modified into knobbed thread like balancing agents known as halters of balancers. 5. Pseudohalters: There are the reduced fore wings of strepsiptera. 6. Brachypterous: In certain grasshoppers the wings are short winged condition is known as brachypterous forms. Wing venation:- The complete system of veins of a wing is termed as venation or narration. Generally in all the insects there is some similarity in wing venation and therefore, it is presumed that all type of wing venation has developed from the common base or the same ancestor. By means of an extensive study of wing venation in different groups of insects, Comstock and Needham constructed a hypothetical type of wing venation from which all other types have presumably derived. According to them the primitive wing venation has developed from two tracked which are situated on the anterior and the posterior basal margin of wings and their branches are spread all over the wing. Each main trachea give rise to three principal veins, thereby forming 6 principal veins namely costa, radius, medius, cubitus, penultimate and ultimate. Each principal veins give rise to sub-vein near its base. The principle veins are represented by+sign whereas the sub-vein by-sign. Thus the whole wing venation system is represented by + and - signs in alternate. The branches of principle veins is represented in the following manner- Costa + C Costa C+ Sub costa Sc- Radius R+ Radius R+1

Radius sector Rs. 5 (-R1 to - R5)

Medius M+ Medius anterior MA+4 (+M1 to +M4)

Medium posterior MP-4 (-M1 to -M4)

Cubitus Cu+ Cubitus Cu1+ (Cu1+1 to Cu1+4)

Subcutius Cu2- (Cu2-1 to Cu2-4) Penultimate A1+ Penultimate +1 Sub penultimate-2 Ultimate A2+ Ultimate+1 Sub ultimate-2 Such type of hypothetical wing venation is never met in any insect as one or the other vein in invariably found lacking for example the medius veins is absent in insect order hemipterous and ephemerid and submedius is missing in order odonata. Some of the scientists consider precostal, costa, subcostal, radius, medius, cubitus and anal as the principle vein of the insect wing. Cross vein:- The veins joining the two longitudinal veins are known as cross veins. The important cross veins along their symbols are as follows- 1. Humeral cross vein (h):- It extends from costa to sub costa near the humeral angle of the vein. 2. Radio-medial cross vein (rm):- It joins the sub radius and the medius veins.

3. Medial cross vein (m):- The vein joining the m2 and m3 branches of medius. 4. Medical-cubital cross vein (m-cu):- It joins the medius and the cubitus longitudinal veins.

5. Radial cross vein (r):- It extends from R1 to R2. The wing coupling apparatus in insects The development of the wing couplings insect is deriving through which they have evolved a better method of using their wings during flight. Among the more primitive insects the two pairs of wings more independently of each other but in other, there appears to be a tendency for using them as a single function unit. This is achieved either by reducing one pair of wings as in diptera or by devising a wing coupling apparatus. 1. Jugal and humeral lobe: This coupling device is commonly found in lepidoptera, trichopteran and mecopterous wherein the wing bases are highly modified. The posterior end of the fore wing is modified into slender finger like organ which is stiffened by a branch of III anal vein is known as the jugal lobe, whereas the anterior margin of hind wing is modified in to a small humeral lobe. The lobe of fore and hind wings are coupled with each other during flight. 2. Frenulum and retinaculum: This type of coupling apparatus is well illustrated in higher lepidoptera wherein its jugum is lost and the frenulum assumed more important. In female butterflies a number of stout bristle beneath the extended fore wing known as frenulum which engages a retinaculum form a patch and fused into a single stout structure and is help by a curved process from the sub costal vein of the fore wing. 3. Hamuli: In this modification the costal margin of the hind wing bears a row of small hooks known as hamuli. These hoks get attached into a fold on the inner margin of the fore wings. Such coupling apparatus is generally met in hymenoptera. 4. Amplexiform: This example is commonly met in the insect belonging to family papilionidae and bombastically of order lepidoptera. In this case the wings are coupled simply by overlapping basically to each other.

Exercise No. - 10

DISSECTION OF GRASSHOPPER/COCKROACH TO EXPOSE DIGESTIVE AND NERVOUS SYSTEM

Dissect to expose In this exercise you are going to study the internal organs of the grasshopper/cockroach. The internal organs include the digestive, nervous and reproductive systems. Directors: Remove the antennae, legs, wings and pronotum with scissors. Hold the specimen with the left hand, keeping the dorsal side of the specimen up, cut off both the lateral margins or the pleural region, (posterior to anterior) and place the insect in the dissecting tray keeping dorsal side up; insert a pin in a slanting position on the head at the region of clypeus to fix the insect on the trey. Holding the tip of the abdomen with the forceps, stretch the insect to its natural position and insect another pin at the tip of the abdomen, slanting backwards. Insert a few more pins in a slanting manner from the body on either side in the thoracic and abdominal region to the specimen in Perfect position. Pour the sufficient water to cover the specimen. Gently lift the abdominal terga with the forceps, insert the dissecting needle below the tergal plate, and work foreword, carefully from posterior to anterior and remove only the tergal plates of the abdomen. Similarly remove the tergal plates of the thoracic region with the help of scissors. Now carefully trace the different systems mentioned above one by one. Digestive system Since the alimentary canal beings at the mouth and ends at the anus it is necessary to expose the epicranium to study the entire length of the alimentary canal. With the help of a fine scissors inside the cervix. Hold the head with the forceps in the left hand and using another forceps gently peals off the epicranium. This should be done with care to retain the brain, which is in between the compound eyes, and the connective intact. After removing the epicranium drain the water, put a drop of Bouvin‟s fluid over the head region leave it for a few seconds and once again add required quantity of water. In grasshopper the alimentary canal is about twice the length of the body. Lift the middle portion of the alimentary canal with a forceps and gently pin out to right side, by separating the tracheae adhering to the gut. Expose the entire length of the alimentary canal and pin to a side of the dissecting tray to study its various regions. The alimentary canal is divisible in to three primary regions (i) the fore gut, Stomodium (ii) the mid gut, Mesontron and (iii) the hind gut, Proctodium. The fore gut leads from the mouth or the preoral food cavity, which opens in to the pharynx. The pharynx is the region between the mouth and the oesophagous. The oesophagous is a simple straight tube running from the hinder region of the head and extends as far back as the posterior parts of the prothorax where it leads in to the crop. The crop is the dilation of the hind portions the oesophagus and the functions as food reservoir and leads to the gizzard or the proventriculus. The gizzard is conical and masticatory in function. Thus the fore gut includes the pharynx, the crop and the gizzard. At the junction of the fore gut and mid gut there are 8 finger shaped tubular structures known as the enteric or hepatic caeca. The mid gut is a narrow short tube that connects the fore gut and the hindgut. At the junction of the mid gut and hind gut there are 8-100 long yellowish hair like structures called the Malpighian tubules which are excretory in function. The hindgut is long and coiled. It has three regions, the anterior ileum; the middle colon and the posterior rectum. The rectum is slightly enlarged and opens out through the anus. Directions: Locate the various regions of the alimentary canal, draw a sketch with an out line of the insect body as seen in your dissection and label all the parts. Salivary glands or the labial glands These are the paired structures situated in the thorax on either side of the fore gut. Their ducts combined to form a median salivar duct, which opens on the labium near the base of hypopharynx. The salivary glands are composed of number of lobes. There are two sac-like salivary reservoirs one on either side associated with salivary glands. The ducts of the reservoirs open in to the median salivary duct. Directions: Locate the salivary glands and the resrvoirs on either side of the oesophagous. Trace the salivary ducts leading to the common duct, which opens below the hypopharynx, at the base of the labium. Take out the entire salivary glands along with the ducts and reservoirs. Keep it on a side with one or two drops of water. Draw and label the parts. THE NERVOUS SYSTEM The insect nervous system could be studied under 3 heads. (a) The central nervous system (b) The visceral nerous system and (c) The peripheral nervous system In grasshopper the central nervous system consist of the brain of the superaoesophaheal ganglion, a suboesophageal ganglion and the ventral nerve cord. The ventral nerve cord bears three thoracic and six abdominal ganglia. The suprraoesophageal and the suboesophageal ganglia lie in the head above and below the oesophagous respectively and these two are connected by lateral connective or circumoesohageal connectively. There are three thoracic ganglia, one in each thoracic segment along the midventral line. The six abdominal ganglia lie in the first six abdominal segments. The last abdominal ganglion is bigger than the rest due to fusion of the posterior ganglion.

The ventral nerve cord All the ganglionic centers are connected to one another by means of longitudinal cords or connective. Each ganglionic center supplies nerves to the respective segment and its appendages. Directions: Proceed dissection as instructed in page and open the viscera. Cut the alimentary canal near the posterior end and pin it out side the body. Open the neck and peel off the epicranium to expose the brain. Drain out the water, put a drop of Bouin‟s fluid, leave for a few second and add required quantity of water gently. Remove the tissues surrounding the brain and the lateral connectivity connecting the brain and suboesophageal ganglia. To ascertain whether the lateral connective sideways, the oesophagus runs between the lateral connectives; the supra and suboesophageal ganglia lying above and below it respectively. Cut the oesophagus close to the brain and pull out the pharynx holding it from anterior end. Now you can see the space between the two ganglia and connectives. Trace further the connectives connecting the suboesophageal ganglion and the prothoracic ganglion. Take care to see that the delicate neck region intact to see these connectives. Clear the tissues of the thorax to expose the deeply embedded thoracic ganglia. The abdominal ganglia are clear except the last one, which lies below the reproductive organs. Now remove the reproductive organs and fat bodies to expose the abdominal ganglia. If necessary apply Bouin‟s fluid again as described earlier. Bouin‟s fluid hardens the nerve tissues and should not be applied to other organs. Make a neat-labeled diagram of the central nervous system and label the parts.

Exrcise No. - 11

DISSECTION OF GRASSHOPPER/COCKROACH TO EXPOSE REPRODUCTIVE SYSTEM

Female Reproductive system It consists of paired ovaries composed of ovarioles; paired oviducts, common oviduct, colleterial gland and spermatheca. The ovaries are compact bodies lying in the body cavity of the abdomen on either side of the alimentary canal. Each ovary is composed of 8 separate egg tubes or ovarioles with long filaments at the apex. Each ovary leads into the oviduct. The long, slender thread like filaments unite to form a common thread called ligament, which holds the oviducts open to the common oviduct or the vagina. A sac like spermathecae with a duct which stores the spermatozoa, opens into the genital chamber the female accessory or colleterial glands also open separately into the genital chamber. Directions: Observe the reproductive organs, make sketch and label the parts. (The sketch should be proportionate to the respective organs mentioned above).

Exercise No. - 12

OBSERVING THE CHARACTERS OF ORDER ORTHOPTERA AND ISOPTERA AND ITS FAMILIES OF AGRICULTURE IMPORTANCE

Orthoptera (Ortho: straight, Pterion: wing) 1. Mouthparts-biting and chewing type 2. Medium or large sized insects 3. The majority of insects have well-developed prothorax and two pairs of wings. The fore wings being thickened nd leathery in texture to form tegmina. The hind wings are membranes, larger than the front pair and folded fan like under fore wings. 4. In some groups the wings are small and half grown or lacking altogether, this condition is known as brachypterous form. 5. The antennae are generally elongated and filiform or setaceous type 6. Metamorphosis incomplete (Hemimetabolous) 7. A pair of compound eyes and three ocelli present 8. Hind legs are modified for jumping, the coxa is small and widely separated, tarsi generally three or four segmented 9. Cerci are present and usually short 10. A thin cuticular membrane or tympanum is present on each side of the first abdominal segment or near the proximal end of each fore tibia Family: Acrididae (Short horned grasshoppers, Locust) 1. The antennae are small than body length 2. Hind legs are well developed with enlarged femora, which are adopted for jumping. There are row of peg like files on the femur used for sound production. 3. The tarsi are 3 segmented 4. Tympanum is located on each side of the first abdominal segment 5. The ovipositor is small and made of 2 pairs of value Insect of this family are often destructive and especially the locust are very destructive to crops and vegetation. Eggs are laid in groups of 30 to 100 or more and the fluid secreted around the egg form a hard covering or „pod‟ which affords water proof protection. Hieroglyphus banian (Rice grasshopper) Chrotogonus spp. (Surface grasshopper) Schistocerca gregaria (Louse)

Family: Tettigonidae (Long horned grasshopper) 1. Antennae are long setaceous type 2. Tympanum organs present on fore tibia 3. Wingless forms are common and mostly live nearer the ground 4. Winged form are mostly green 5. Ovipositor is sword shaped 6. The eggs are thrust into plant tissue in longitudinal rows and some laid in the soil Example: Tetigonia viridissima Phoidoptera griseoaptera

Isoptera (Iso: equal, Pteron: Wings) 1. Soft bodied, creamy white insect 2. Mouthparts are of chewing and biting type 3. These are social insects of different castes live together in colonies (queen, king, complimentary form) and sterile and solders. 4. Wings-apterous, branchypterous or winged forms the wings, individual possess two pairs of long narrow wings, similar in size, shape and venation. 5. Metamorphosis incomplete 6. Tarsi 4 segmented 7. Antennae moniliform, short or long, many segmented 8. Cerci is small and some time rudimentary 9. Genital always wanting or rudimentary in both sexes

Family: Kalotermitidae (Wood dwelling termites) 1. Workers caste is absent 2. Ocelli are usually present 3. Tarsi 4 segmented 4. Anterior wing scale long Example: Kalotermes indicus Cryptotermes domesticus

Family: Termitidae (Ground dwelling termites) 1. The worker caste well developed 2. Compound eyes are present 3. The wings are very slightly reticulate and anterior wing scale short Example: Macrotermes serrulatus Odontotermes obesus Family: Rhinotermitidae (Subterranean termites) 1. Worker caste present 2. Anterior wing scale are usually long 3. Compound eyes are present Example: Coptotermes ceylonicus Rhinotermes spp.

Exercise No. - 13

OBSERVING THE CHARACTERS OF ORDER LEPIDOPTERA AND THYSANOPTERA AND ITS FAMILIES OF AGRICULURE IMPORTANCE

Lepidoptera (Lepidos : scales, Pteron: wings)

1. It includes insects of small to large sized having wing span upto 30 cm 2. Mouthparts-chewing and biting type in caterpillars and siphoning type in adults 3. Wings-two pairs of membranous wings covered with a layer of beautiful scales. Cross veins few in number 4. The head is small, hypognathus type 5. Compound eyes are comparatively large and the ocelli are generally present 6. Metamorphosis complete 7. Larvae feed on foliage, roots and fruits and grains whereas adults feed on nectars of flowers 8. Legs relatively small, tarsi 5 segmented 9. Larvae with 3 pairs of thoracic legs and 5 pairs of abdominal legs 10. Pupa enclosed in a cocoon or an earthen cell 11. Tarsi 5 segmented The order is generally divided into Heterocera (moths) and Rhopalocera (butterflies) simply because of the difference in general appearance of two groups. Some have divided the order into Macro and Micro lepidoptera simply on the basis of size. According to Imms (1961) the order may be divided into three sub orders. His classification was based on works of several authorities and hence most accepted ones. Sub order: Zeugloptera 1. Adults with functional mandibles 2. Lacinia is nor well developed and galea is not forming proboscis 3. The female genital chamber opens in the main oviduct Sub order: Monotrysia 1. Mandibles are vestigial 2. Lacinia is absent 3. Females with one or two genital opening behind the 9th abdominal sclerite

Sub order: Ditrysia Largest sub orders having families of Agricultural impotence 1. The female has a copulatory pore on 8th sclerite and egg pod on 9th 2. The fore wing are without jugam lobe 3. The hind wings are often without frenulum and reduced venation Family: Gelechidae 1. Small to medium sized moths of dull color 2. The fore wings are narrow than the hind wings 3. Maxillary pulp are either absent or rudimentary 4. Labial pulp one three segmented and directed arterially 5. Hind tibia possess hard hairs Example: Cotton boll worm Pectinophara gossypiella Potato tuber moth Gnorimoschema operaculella Family: Noctuidae (Largest family of Lepidoptera) 1. Medium to large insects and generally of brown colour 2. These are nocturnal in habit and light lover 3. The caterpillars usually leaf feeder or stem or root-borers 4. The antennae are filiform in female and pectinate in male 5. The fore wings are rather narrow and somewhat elongate 6. A frenulum is present 7. Pupation takes place in an earthen cell in the soil 8. In adults stage few noctuids pierce the fruits and feedings causes rotting and premature fall of attack fruits Example: Castor semilooper Acheae janata Gram pod borer Helicoverpa armigera Fruit sucking moth Othreis materna Pink borer Sesamia inferens Tobacco caterpillar Spodoptera litura Family: Pyralidae 1. Small to moderate sized moth with labial pulp projecting snout like 2. Compound eyes and ocelli are present 3. Fore wings are narrow while hind wing are board 4. The larvae feed on leaves, fruits, flowers and stems and most of them are border Example: Cotton leaf roller Sylepta derogata Maize stem borer Chilo partellum Sugarcane short borer C. infuscatelus Family: Bombycidae 1. The antennae are pectinate in both the sexes 2. The larvae glabrous and elongated having anal horn on the 8th abdominal segment 3. The larvae form dense silken cocoon Example: Silk worm, Bombyx mori Family: Saturnidae 1. These are stout and broad winged insects 2. Antennae are bipectinate in both the sexes 3. The labial palpi are minute 4. Caterpillar feed on leave and large cocoon 5. The caterpillar are bodied with spiny or tufts of hairs and may attain the length of 7-8 cm Example : Eri silkworm Philosamia ricini Munga silkworm Antheraea paphia Tasar silkworm Antheraea paphia Family: Pieridae 1. These are generally medium sized butterfly 2. The colour of wings are almost yellow, orange or while usually marked with black 3. The claws of legs are tooted 4. The larvae are green and covered with five and short hairs 5. There is a cephalic spines on the head of the pupa Example: Cabbage butterfly, Pieris brasscea Family: Papillionidae 1. Generally large butterflies of bright colour 2. The wings are black and are generally marked with yellow and frequently with green and blue 3. The hind wings possess tail like prolongation 4. The caterpillars are naked or sometimes covered with five hairs Example : Lemon butterfly, Papilio demoleus Order: Thysanoptera (Thysano: fringe, Pteron: wings) 1. Insects are action, small in size 0.5 mm in length and found feeding on flower and foliage. They are yellow, yellowish brown or black in colour 2. Mouth part is rasping and sucking type 3. Wings to pairs, similar in form, long, linear with few veins, membranous and fringed with hairs, some time apterous 4. Metamorphosis intermediate between single and complete, there is a pupal instar preceding the adults (egg-nymph-pupa-adult) 5. Antennae short and 6-10 segmented 6. Tarsi 1-2 segmented 7. Carci absent 8. Prothorax well developed 9. Body is covered with a sclerotized cuticle and the integument often shows characteristic sculpture patterns Family: Thripidae 1. Antennae 6-9 segmented 2. Fore tarsus never with claw like appendage at base of 2nd segment Example: Thrips tabci Scirtothrips dosalis

Exercise No. - 14

OBSERVING THE CHARACTERS OF ORDER HEMIPTERA AND HYMENOPTERA AND ITS FAMILIES OF AGRICULTURE IMPORTANCE

Hemiptera (Hemi: half, Pteron: wings, means partly thickened and partly membranous wings)

1. Mouthparts are piercing and sucking type in which labiumis adapted in the form of a beak or rostrum with 4 piercing stylate (2 mandibles and 2 maxillae) 2. Wings two pairs of wings present, forewings are harden in consistency than the hind wings whichare membranous 3. Minute to medium sized, soft bodied, elongated oval insects 4. The carci are absent 5. Head free (movable) opisthognathous the long axis of head is vertical and mouthparts are directed downward and backward in between first pair of thoracic legs. 6. The antennae are 4-10 segmented 7. Tarsi are 1-3 segmented Sub order Homoptera (Hopper, whiteflies, aphids, scale insects, cicads) Heteroptera (Bugs) Sub order : Homoptera 1. Pronotum is small 2. The rostrum arises from the back of the head 3. The forewings are uniform in texture (Apterous forms are frequent in one or both sexes. Both winged and wingless individuals occur in same sex). 4. Metamorphosis is usually incomplete 5. Head more or less deflexed (downward) 6. Sexual reproduction is common but parthenogenesis and viviparity is also found 7. Tarsi 1-3 segmented Family: Fulgoridae 1. The family is chiefly characteristic by reticulate anal area of the hind wings and elongated beak or rostrum 2. The antennae are 3 segmented 3. Generally 2 ocelli are present 4. The wings are membranous, small and not fully covering the abdomen 5. Tarsi 5 segmented 6. They are mostly gray insect and female is provided with anal taft Example: Sugarcane leaf hopper, Pyrilla perpusilla Family: Aleurodidae (whiteflies) 1. Consists of small insects and restricted to tropics and sub tropics but few are found in cooler regions 2. All species live on the leaves of plants and mostly on under surface 3. Insects have 7 segmented antennae, two ocelli and pairs of reniform (kidney shaped) compound eyes 4. The body is generally covered with white waxy powder 5. The vasiform orifice opens on the dorsal surface of the last abdominal segment. The opening is covered with an operculum under which there is a tongue like organ termed lignla 6. The anus opens at the base of the ligula and secretes honey dew on which a shooty mould developed and gives a black appearance to the leaves 7. Metamorphosis approach the holometabolous type which is an exception in this family. The egg hatch into larvae, with the first moult they lose their legs, antennae following the additional moulds, the insect enter pupal stage from which winged adult emerged 8. Reproduction by parthenogenesis Example : Sugar white fly Aleurolobus barodensis Cotton white fly Bemisia tabaci Citrus white fly Dialeurodes citri Family: Aphidiae 1. Small soft bodied, delicate, pear shaped insect that sucking the sap of leaves and inflorescence of plants causing serious damage 2. Both winged and wingless forms are found 3. The head hypognathous, small and fused with thorax 4. The antennae are 3-6 segmented the compound eyes and 3 ocelli are present 5. The tarsi are 2 segmented with paired claws 6. The cornicles or honey tubes are most characteristic organs (absent only in few species) located on the 5th abdominal segment it secrete a waxy fluid, which provide protection from predaceous insects. 7. In the 9th tergum of abdomen, anus is situated which secrete honey dew 8. Aphid reproduced by parthenogenesis, viviparity or ovoviviparity Example : Cotton aphid Aphis gossypii Mustard aphid Lipaphis erysimi Paddy aphid Rhopalosiphum maidis Family: Jassidae or Cicadellidae (Jassid) 1. Generally small, elongate, cylindrical insects having eight segmented setaceous type antennae 2. The double row of spines are present on the hind tibia 3. The compound eyes are large situated on the lateral surfaces of the head and two ocelli are also presented 4. Thorax is narrow than head and attached with the abdomen without any prominent division 5. Tarsi 3 segmented 6. Mostly rest on the lower surface of leaves and when disturbed they leap often several feet and fly 7. The leaf hopper are usually about 1/4 inch in length and usually tapering posteriorly Example : Mango hopper Amritodus (Idiocerous) atkinsoni Pappy leafhopper Nephotettix spp. Cotton jassid Amrasca bigutella bigutella Family: Coccidae (mealy bugs) 1. The insects are quite small, body is compressed and covered with whitish meal 2. The males are generally winged and the fore wings are only well developed 3. The female is wingless and round in structure 4. The legs are highly reduced and tarsi one segmented 5. The metamorphosis is complete in male and incomplete in female 6. The mouthparts are absent in male adult hence they do not feed in the adult stage Example : Mango mealy bug Drosicha mangiferae Family: Laceiferidae (lac Insect) 1. Small insect with irregular globular body 2. Legs and abdominal spiracles are absent 3. Both winged and wingless males are found having 4 ocelli 4. Antennae 3 or 4 segmented Example : Laceifer lacca

Sub order: Heteroptera (Hetero: different, Pteron: wings) 1. The rostrum arise from the front part of the head 2. Two pairs of wings are always found in which forewing is thickened at the base and membranous at apical portion these are called hemelytra 3. Metamorphosis is incomplete 4. Antennae 5 or few segmented 5. Body usually broad and flattened dorsoventrally 6. Pronotum large and distinct. A plate usually triangular in shape called scutellum located between the base of the wings Family: Pentatomidae 1. The head is small, triangularly 2. Medium to large sized bugs 3. A pairs of compound eye and two ocelli are present 4. Scutellum is very large, reaching about one half or more distance from posterior margin of pronotum to the end of folded wings 5. Antennae 5 segmented 6. Tarsi 2 or 3 segmented Example : Painted bug, Bargada cruciferanum Family: Coreidae 1. Minute to medium size bugs 2. Both rostrum and antennae 4 segmented 3. A pair of compound eyes and two ocelli are present 4. Metathorax possesses a pairs of odour glands which are capable of producing disagreeable odour Example : Rice gundhi bug (Leptocorisa varicornis) Family: Pyrrhocoridae 1. Medium to large sized insects 2. Both antennae and rostrum 4 segmented 3. Ocelli absent 4. Tarsi 3 segmented 5. The prothorax is large and its distal ends are broader than the mesothorax Example : Red cotton bug, Dysdercus cingulatus Other families 1. Cimicidae : Bed bug Cimed lectularius 2. Tingidae : Bringal bug Ulrentius echinus 3. Lygacidae : Dusky cotton bug Oxycarenus latus

Hymenoptera (Hymen: Membrane, Pteron: wings) 1. Mouthparts are chewing and biting type in larvae and chewing and lapping type in adults 2. Two pairs of membranous wings, hind wings are smaller than fore wing and interlocked by means of hooks 3. Metamorphosis complete 4. Antennae ranged from 3-60 segments and are filiform, geniculate or pectinate 5. Compound eyes are well developed and generally three ocelli are present 6. Abdomen of female is generally provided with a saw, piercing organ or sting 7. Tarsi 5 segmented Example : Bees, Wasps and Ants Suborder: Symphyta 1. The abdomen broadly joined to the thorax. No marked constriction between 1st and 2nd abdominal segment 2. Trochanter 2 segmented 3. The larvae feed on or in plant and caterpillar like in appearance. They have well developed thoracic and abdominal legs Family: Tenthredinidae 1. Small to minute sized saw flies 2. Insects are found on flower or foliage and some are carnivorous feeding on small insects 3. The ovipositor consists of plates 4. The claws are toothed 5. The larvae pupate in an elongate oval silken cocoon on earthen cell Example: Mustard saw fly, Athalia proxima Suborder: Apocrita (wasps and bees) 1. The first segment of the abdomen fused with thorax, abdomen deeply constricted at the basal joint 2. Larvae are apodous 3. The adults feed on sap, flower and plant material Family: Ichnenmonidar (Ichnenomous parasites) Example : Isotima javensis, larval parasite of sugarcane top borer Xanthopimple punctata, parasite of Chilo partellus larvae Family: Braconidae (Braconid parasite) Example : Bracon brevicornis, parasite of coconut caterpillar Apanteles flavipes, parasite of Chilo partellus and Amsacta sp. Family: Trichogrammatidae (Egg parasite) Example : Trichogramma spp., egg parasite of Chilo partellus Family: Aphelinidae Example : Aphelinus mali, parasite of wooly apple aphid Family: Chalcididae Example : Meyeriella indica, larval parasite of coconut caterpillar Family: Apidae Example : Apis dorsata, A. florae, A. indica, A. mellifera Family: Forrmicidae Example : Red ant, Formica fusca, F. sangninea

Exercise No. - 15

OBSERVING TE CHARACTERS OF ORDER COLEOPTERA AND ITS FAMILIES OF AGRICULTURE IMPORTANCE

Coleoptera : (Coles: Sheath Pteron: wings) Largest order of class Insecta (220,000)

1. Mothparts - chewing and biting type 2. Stout body, minuted large insect 3. Wings-two pairs, forewings are modified into horny (hard) or leathery- protective sheath called elytra hind wings membranous 4. Metamorphosis complete 5. Prothorax large and mobile, mosothorax much reduced 6. Tarsi 4-5 segmented 7. Cerci and ocelli absent 8. Larva Called grub having 3 pairs of thoracic legs

Sub order Adephaga Polyphaga Sub order: Adephaga : 1. Insect feeds on other insects 2. Tarsi 5 segmented 3. Antennae filiform Family : Carebidae (Predaceous ground beetle) Example : Anthia seggutala (feeds on whitegrup)

Sub order: Polyphaga 1. Insects feed on grain, leaves and on other insects 2. Tarsi 5 segmented and single claw is present Family : Curculionidae (weevil) 1. The adults are specified by the prolongationof the head into distinct snout 2. The mouthparts are located at the tip of the snout 3. Antennae are genicuate, clubbed or clavate type 4. The larvae are legless grub, generally having dark head and white bodies Example : Rice weevil, Sitophilus oryzae Family : Chrysomelidae (leaf beetle) 1. Small to moderate sized insects 2. Antennae long filiform 3. Tarsi 4 segmented 4. Most of grubs are stout with short legs and antennae 5. Abdomen is short and five segmented 6. Wings are simple and completely cover the abdomen Example : Red pumpkin beetle, Raphidopalpa foveicollis Family: Dermestidae 1. The head is hypognathus and antennae are small clavate type 2. The wings are simple and completely cover the abdomen 3. The larvae remain covered with dense hairs 4. Compound eyes large large and one ocellus is present Example : Khapra beetle, Trogoderma granarium Family: Tenebrionidae 1. The body is hard, often flattened, globular beetle 2. Antennae are short under the projection of the sides of the head 3. Some species are apterous with vestigial or no wings 4. The elytra fit closely to abdomen Example : Rust red flour beetle, Tribolium castaneum Meal worm, Tenebrio molitor Family: Bruchidae or Lariidae 1. Adults are small, short, stout bodied covered with setae or scales. The elytra are short and do not cover the tip of abdomen 2. Head is hypognathus type 3. Antennae clavate or serrate or pectinate type 4. The larvae feed extensively on seeds of legumes Example : Pulse beetle, Callosobruchus chinensis, C. maculatus, C. analis Family: Bostrychidae 1. Beetles are small or large, black or reddish brown, elongated, cylindrical with hood like pronotum concealing the hypognathus head 2. Clubbed antennae 3. Larvae is characteristi with redued head 4. These insects makes cylindrical burrow Example : Lesser grain borer, Rhizopertha dominica

Family: Coccinellidae (lady bird beetle) Example : Coccinella septempuntata Menochilus sexmaculatus Family: Scarabidae (Melolonthedae) 1. The beetles are variously coloured, black, brown, green or blue 2. Beetles are commonly attracted to light 3. Antennae 811 segmented 4. Elytra are short and do not cover the abdomen completely 5. The grubs are fleshy, white with brown head curved („C‟ shaped) body Example : White grub, Holotrichia consanguinea, H. serrata Family: Rutelidae (shinning leaf chafers) Example : Anomala bengalensis

Exercise No. - 16

OBSERVING THE CHARACTERS OF ORDER DIPTERA AND ITS FAMILIES OF AGRICULTURE IMPORTANCE

Diptera (Di: two, Pteron: wings) 1. Mouthparts: piercing and sucking type and sponging type 2. Minute to medium sized insects 3. Wings: single pair of membranous wing, hind pair of wings reduced to small knob called halters, forewing used for flight 4. Metamorphosis complete 5. Pro and mesothorax are comparatively small while the metathorax is large 6. Tarsi 5 segmented 7. Larvae (maggot) apodous (without legs) 8. Pupa either free or enclosed in the harden larval cuticle or puparium 9. Adult feed on nectar of the flowers, decaying organic matter, dung, excreta. Some are predaceouson other insects while other suck blood of man and cattle Example : Flies and mosquitoes Suborder: Nematocera 1. Antennae are long, many segmented, larger than the head and thorax 2. Palpi usually 4 or 5 segmented, pendulous 3. Pupa free Family: Cecidomydae (gall midge) 1. Minute delicate flies with long moniliform antennae 2. Ocelli present or absent 3. Wings with few longitudinal veins 4. Coxa not elongated, tibia devoid of spurs 5. Larvae peripneustic (nine spiracles are open, meta thoracic spiracles closed) Example : Sorghum midge, Contarinia sorghicola Rice gall midge, Pachydiplosis oryzae Family: Culicidae (mosquito) 1. Mouthparts piercing and sucking type 2. No ocelli 3. Larvae and pupae are aquatic Suborder: Brachycera 1. Antennae shorter than the thorax, generally three segmentd 2. Palpi 1-2 segmented 3. Larvae have hooked or blade shape mandibles 4. Pupa free