PESTS OF COTTON

We can observe number of pests in cotton. They cause severe damage in plants hence destroy the crop and finally decrease the yield.

Cotton Aphids

Causal organism : Aphis gossypii

Symptom of damage

• They are mainly found on tender shoots and under surface of the leaves

• They causes curling in leaves

• Stunted growth can be observed in severe infestation

• Blighted appearance when infestation is severe

• Development of black sooty mould due to the excretion of honey dew giving the plant a dark appearance which leads to decreased yield.

Identification

• Eggs

          Are yellowish in colour and are found on under surface of leaves

• Nymphs

These areYellowish or greenish brown in colour and mainly found on the undersurface of leaves

• Adults

 Are Greenish brown in colour and soft bodied small insects

Management

1. Use Bio r 303 1.5ml/lit

• Acetamaprid 50g/ha

• Thiomethaxam+Lamdacyalothrin 5ml/lit

• Fipronil 5%+Acetamaprid at 600-800ml/ac

Thrips

Causal organism: Thrips tabaci

Symptom of damage

• These suck the cell sap from the leaves and scrapping leads to shriveling of young leaves

• They attacks terminal buds

• Silvery shining appearance can be seen on the undersurface of leaves

Identification

• Eggs

  Are ablong and are pale yello in colour laid singly

• Nymphs

These are very minute, slender, yellowish and microscopic in nature.

• Adult 

Small, slender, yellowish to brown with fringed wings

Management

1. Use Bio R 303 1.5ml/lit

• Acetamaprid+damman plus at 5ml/15 lit of water

• Shine 50ml/20l of water+Brand liquid

• Apply Willoprid at 40g/acre

Mealy Bugs

Causal organism: Maconellicoccus spp.

Symptom of damage

• Mealy bugs are usually found in the group on under surface of the leaves as a thick mat with waxy secretion

• They excretes honey dew on which the fungus sooty mould grow( Black powder like structure).

• Affected plants appear sick and black, resulting in reduced fruiting capacity and finally yield.

Identification

• Eggs

Are laid in groups (100-200)

• Nymphs

Nymphs are light pale in colour

• Adults

Management

1. Apply melathion at 2-2.5ml/lit

• Sparay with dimethoate at 1ml/lit

Pink Bollworm

Causal organism: Pectinophoragossypiella

Symptoms of damage

• Rosetted flowers can be seen.

• Excreta can be 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 will drop down.

• Discolored lint and burrowed seeds can be seen.

Identification

Larva

• They shows variation incolour. Young larva are white and late instar becomes almost black, brown or green to pale/pink
• Several dark and light alternating bands run the entire length of the body

Adult

• These are small moths
• Forewings are brown or dull yellow olive grey with dark spots
• Hind wings margins are deeply fringed 

Management

1. Use Profinophos at 2-2.5 ml/acre

• Emamectin benzoate at 4g/10lit

White fly

Causal organism: Bemisiatabaci

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

Identification of the pest

• Eggs

Are spirally laid on undersurface of leaves

Nymph

These are greenish yellow in colour and oval in shape

Pupa

These are Oval(black or white) in shape and present on the under surface of the leaves

Adult

 AreMinute insects with yellow body covered with a white waxy bloom

Management

1. Use Dicentrionwillqueen at

• Diata at 500ml/ha

• Takaf at 250ml/acre

• Acetamaprid 200g/ha

Tobacco cutworm

Causal organism: Spodopteralitura

Symptoms of damage

• It scrapes the epidermal layer, leaving the skeleton of veins of leaf

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

• Larva feeds the leaves by making small holes and hence the cotton crop will be destroyed.

Identification of the pest

• Egg

Arelaid in masses which appear golden brown

• Larva

Are 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

Management

1. Use Chlorpyriphos EC @ 2.5ml/lit

• Emamectin benzoate SG at 5g/20 lit of water