Insect

Scientific name

Symptoms of damage

Management

Ash weevlis

Mylloecerus undecimpustulatus

· Nicked leaf margins

· Patched leaf wilting

· Weak roots grip

· Destroyed roots

Cultural:

· Eradication and destruction of affected plant parts

Chemical:

· Insecticidal spray (Quinalphos or chlorpyriphos)

Cotton aphid

Aphis gossypii

· Leaf crunkles

· Stunted plant growth

· Leaf blight

· Dark plant appearance due to black mould

· Tender leaves & shoots

Chemical:

· Insecticidal sprays (Methyl demeton, Acetamiprid, Carbosulfan, Fipronil, Imidacloprid or Malathion)

Cotton stem weevil

Pempheres affinis

· Stem swelling

· Young plant death

· Nodal breakage during wind

· Lack of vigor & strength in mature plant

Cultural:

· FYM application

· 10% - 20% Infestation

Chemical:

· Seed treatment (Chlorpyriphos)

· Insecticidal spray (Carbaryl or carbofuran)

Dusky cotton bug

Oxycarenuchyalinipennis

· Sap sucking

· Lint blackening

· Shrunken seeds

· Seeds discoloration

Chemical:

· Insecticidal Phosphamidon spray

Fruit borer

Helicoverpa armigera

· Boll feeding

· Regular circular bore holes

· 30 - 40 bolls damaged by a single larva

· Granular faecal pellets outside bore holes

Cultural:

· Synchronized sowing with short duration varieties

· Avoid continuous cropping

· Avoid monocropping

· Destruction & removal of crop residues

· Water management for larval harborage

· Avoid moth multiplication with optimized use of nitrogenous fertilizers

Biological:

· Nuclear Polyhedrosis virus

· Bacillus thuringiensis

· Beauveriabassina

· Natural predators & parasitoids

· Egg parasitoid, Trichogramma spp.

Chemical:

· At early stage of square formation (Acephate, carbaryl, Diflubenzuron, Lufenuron or Pyridalyl)

· During boll formation and maturity (Quinalphos, Carbaryl or Pyraclofos)

Leaf hopper

Amrasca devastans

· Leaf yellowing

· Leaf curling

· Bronze colored leaf hopper burn

· Crumbled leaf margins

· Leaf shedding

· Complete crop destruction

Chemical:

· Insecticidal spray (Carbofuran, Imidacloprid, Buprofezin, Fipronil, Phosalone or Thiacloprid)

· Neem oil treatment

Leaf roller

Sylepta derogate

· Leaf rolling

· Biten marginal leaf portions

· Crop defoliation

Cultural:

· Picking & destroying of broken & shedded leaves

· Manual picking & destruction of young caterpillers

Chemical:

· Insecticidal sprays (Chlorpyriphos or dichlorovos)

Meally bug

Phenacoccus species

· A mat of mealy bugs under leaf surface

· Thick wax emission

· Honeydew secretion

· Development of black mould

· Black plant appearance

· Diminished fruiting

Cultural:

· Weeds eradication

· Parasitoids

Chemical:

· Spray with Profenophos

· Treatment with neem oil