cotton insects a lecture by mr allah dad khan

Cotton Crop Insects A Presentation To IPM

Course/FFS Participants By

Mr. Allah Dad Khan Provincial Coordinator IPM KPK

For MINFAL Pakistan

Cotton Insects Crop: Cotton Scientific

name: Gossypium spp Family: Malvaceae

1.Fruit borer: Helicoverpa armigera

Symptoms of damage

1. Bolls showing regular, circular bore holes

2. Larvae seen feeding on the boll by thrusting their heads alone inside and leaving the rest of the body outside

3. Presence of granular faecal pellets outside the bore hole

4. A single larva can damage 30-40 bolls

Feeding Injury


• Egg- Spherical in shape and creamy white in colour, present singly• Larva- Shows colour variation from greenish to brown. It has dark

brown grey lines on the body with lateral white lines and also has dark and pale bands.

• Pupa- Brown in colour, occurs in soil, leaf, pod and crop debrisAdult :

• Light pale brownish yellow stout moth• Forewings are olive green to pale brown in colour with a dark

brown circular spot in the centre• Hind wings are pale smoky white with a broad blackish outer

margin

• Identification of the pest


Egg/Larva/Pupa/Adult

2.Pink bollworm: Pectinophora gossypiella

Symptom of damage

• Rosetted flowers• Excreta observed at the point of

bore holes by larval feeding. When bolls are opened, damaged seed kernel would be observed.

• They cut window holes (interlocular burrowing) in the two adjoining seeds thereby forming "double seeds"

• The attacked buds and immature bolls drop off

• Discolored lint and burrowed seeds

2.Pink bollworm: Pectinophora gossypiella

Identification of the pest

• Larva• Shows colour variation. Young larva are

white and late instar becomes almost black, brown or green to pale or pink

• Several dark and light alternating bands running the entire length

• Adult• Small moth• Forewings are brown or dull yellow

olive grey with dark spots• Hind wings margins are deeply fringed •

Adult

3.Spotted bollworms: Earias vittella, Spiny bollworm: Earias insulana

Symptom of damage• • Drying and drooping of

terminal shoots during pre-flowering stage

• Shedding of squares and young bolls

• Flaring up of bracts during square and young boll formation stage

• Holes on bolls and rotting of bolls

Drying - terminal shoots

3.Spotted bollworms

Bore holes and rotting Flared square

3.Spotted bollworms

Identification of the pest: • E. vitella• Larva- Brownish with white streaks dorsally and

pale yellow ventrally, Without finger shaped processes

• Adult• Small buff coloured• Forewings are pea green with a wedge shaped

white band running from base to out margin• Identification of the pest: E. insulana• Larva- Brown with dorsum showing a white

median longitudinal streak. The last two thoracic segments and all the abdominal segments have two pairs of fleshy tubercles (finger shaped processes) one dorsal and the other lateral

• Pupa - Brown and boat shaped• Adult - Small buff coloured. Forewings are

uniformly silvery green

E. vitella - Larva

3.Spotted bollworms

E. vitella - Adult

E. insulana - Larva

4.Cotton Stem Weevil: Pempheres (Pempherulus) affinis

Symptoms of damage

• Swellings on the stem just above the ground level

• Young plants are invariably killed

• Older plants that survive lack vigor and strength, breaks at the nodes due to strong wind

Stem Gall

4.Cotton Stem Weevil

Stem Gall Grub

4.Cotton Stem Weevil


• Larva - Grub, white in colour without leg (apodous)

• Adult - Very small weevil, dark in colour with two small white patches on the elytra

5.Shoot weevil: Alcidodes affaber

Symptoms of damage

• Terminal shoots with galls• Bore hole surrounded by

raised margins



• Adult - Weevil dark greyish brown with pale cross bands on the elytra


Symptoms of damage

• Plants with drooping leaves• Wilting in patches

Affected Stem/Infested Plant



• Adult - Dark brown jewel beetle

6.Leaf roller: Sylepta derogata

Symptom of damage• Leaves rolled in the form of

trumpets fastened by silken threads

• Marginal portion of leaves eaten away

• Plants defoliated in severe attack

Rolled Leaves

6.Leaf roller: Sylepta derogata Identification of the pest

• Larva- Bright green (glistening) with dark head and prothoracic shield

• Adult- Moth with yellow wings having brown wavy markings

7.Tobacco Cutworm: Spodoptera litura

Symptoms of damage

• Scrapping the epidermal layer, leaving the skeleton of veins of leaf

• During severe attack, only the stem and side shoots will be standing in the field without any leaf or bolls

• Larvae feed the leaves by making small holes

7.Tobacco Cutworm: Spodoptera litura


• Egg - Laid in masses which appear golden brown

• Larva- Pale greenish with dark markings. Gregarious in the early stages

• Adult: Forewings- brown colour with wavy white marking

• Hindwings- white colour with a brown patch along the margin

8.Ash weevils: Mylloecerus undecimpustulatus maculosus M. subfasciatus

M. viridanus M. discolor

Symptom of damage• • Leaf margins notched• Wilting of plants in patches• Plants come easily when

pulled• Roots eaten away by grubs

8.Ash weevils


• Grub - Small, white apodous grub

• Mylloecerusundecimpustulatus – Greenish elytra having dark lines

• M. subfasciatus - Brownish weevil

• M. viridanus –small light green weevil

• M. discolor- brown weevil

9.Leafhopper: Amrasca (Biguttula biguttula) devastans

Symptoms of damage

• Tender leaves become yellow• The margin of the leaves start curling

downwards and reddening sets in• In the case of severe infestation,

leaves get a bronze or brick red colour which is typical “hopper burn” symptom

• The margin of leaves gets broken and crumbles into pieces when crushed

• The leaves dry, shed and the crop growth gets retarded

8.Ash weevils


• Nymph - Light green, translucent, wingless found between the veins of leaves on the under surface

• Adult - Green, wedge shaped leafhopper.

9.aphid: Aphis gossypii

Symptom of damage

• Infesting tender shoots and under surface of the leaves

• Curling and crinkling of leaves• Stunted growth• Blighted appearance when

infestation is severe• Development of black sooty

mould due to the excretion of honey dew giving the plant a dark appearance

9.aphid: Aphis gossypii


• Nymphs - Yellowish or greenish brown found on the undersurface of leaves

• Adults - Greenish brown, soft bodied and small insects

• Winged forms may be seen under crowded conditions

10.Thrips: Thrips tabaci

Symptom of damage

• Shriveling of leaves due to scrapping of epidermis and de-sapping

• Attacked terminal buds-have ragged edges

• Silvery shine on the undersurface of leaves

10.Thrips: Thrips tabaci


• Nymphs - Very minute, slender, yellowish and microscopicAdult - Small, slender, yellowish to brown with fringed wings

11.Whitefly: Bemisia tabaci

Symptom of damage

• Chlorotic spots on the leaves which latter coalesce forming irregular yellowing of leaf tissue which extends from veins to the outer edges of the leaves

• Severe infestation results in premature defoliation

• Development of sooty mould• Shedding of buds and bolls and

poor boll opening• It also transmits the leaf curl virus

diseases of cotton

11.Whitefly: Bemisia tabaci


• Nymph- Greenish yellow, oval in outlinePupa- Oval in shape, present on the under surface of the leavesAdult- Minute insects with yellow body covered with a white waxy bloom

Nymph/Pupae/Adult

12.Red cotton bug: Dysdercus cingulatusi

Symptom of damage

• Red stained lint and rotting bolls

• Inner boll wall with warty growth or water soaked spots

• Young bolls abort and turn dark brown

• The bacterium Nematosporagossypii enters the site of injury and stains the fibre

12.Red cotton bug: Dysdercus cingulatusi


• Nymphs and Adults - Reddish bugs with white bands on the abdomen and black markings on the wings

13.Dusky cotton bug: Oxycarenushyalinipennis

Symptom of damage

• Sucks the sap from developing seeds in open bolls and stains the lint black

• Seeds discolored and shrunken

13.Dusky cotton bug: Oxycarenushyalinipennis


• Eggs - Cigar shaped, white eggs in clusters of 2-10 within the half opened bolls, on the bolls, flower or buds

• Nymphs and adults - Dusky, greyish brown bug, with pointed head and hyaline wings

14. Mealy bugs: Phenacoccus sp, Ferrisa spand Maconellicoccus

sp Symptom of damage

• Heavy clustering of mealy bugs usually seen under surface of leaves as a thick mat with waxy secretion

• Excrete copious amount of honey dew on which the fungus sooty mould grow

• Affected plants appear sick and black, resulting reduced fruiting capacity

cotton insects a lecture by mr allah dad khan

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