- World wide, potential pest – Highly polyphagous, wider host range
- Nymphs and adults desap on young crop in colonies.
- Tender leaves curl up, reduced in size, gradually fade and dry up.
- Plant growth severely shunted. Leaves show oily appearance
- Sooty mould develops on honey dew on lower leaves
- Ants are seen moving briskly on plants
- Adults and nymphs are yellowish / greenish brown in colour. Alate and apterous forms are seen. Reproduce parthenogenetically and are viviparous.
- Life cycle – 7-9 days
Leaf hopper/ jassid, Amrasca devastans Cicadellidae : Homoptera
- Damage on young seedlings may be 80-100%.
- Hosts: Bhendi, hollyhock, brinjal, potato, mesta, sunflower, cucurbits.
- Dry conditions in early stages favour the pest.
- Adults- greenish / greenish yellow. wedge shaped
- Nymphs- Initially pale yellow turning green slowly. Eleven generations in a year is observed.
- Symptom: Toxemia (by injection of saliva into plant tissues by nymphs and adults) resulting in hopper burn.
- Initially leaf margins turn pale green, yellow and finally brick red or brown.
- Leaves become crinkled and curled resulting in complete drying and dropping of leaves. Plants stunted. Number of flowers, bolls, seed weight, and quality of lint reduced.
- Hosts : Bhendi, Chillies, brinjal, onion, tomato, sunflower, mango, citrus, tea
- T. tabaci – on flower ; S. dorsalis – on leaves
- Nymphs and adults lacerate tissues, desap .
- Leaves shrivel with ragged edges, brittle, fall off mal formed- Silvery metallic sheen on leaf under surface
- Adults, small, yellowish or brown with fringed wings ; Nymphs – minute, slender yellowish. Life cycle: EP: 2-3 d; NP: 5-8 d; PP: 3-5 d.
- Serious pest on cotton whenever synthetic pyrethroids are indiscriminately used. Highly polyphagous
- Hosts: Tobacco, Cassava, bhendi, hollyhock, safflower, sunflower etc.,
- Nymphs found in colonies on leaf under surface and desap.
- Leaves turn chlorotic, drop down, Sooty mould, Reduced vigour, boll-shedding, buds, flowers, improper boll-bursting.
- vector of Cotton leaf curl disease
- Adult- Small, moth like with white hyaline wings dusted with white powdery scales, body yellow. Nymphs : Green-on leaf undersurface.
- 10-12 generations / year
Red Cotton bug / Stainer, Dysdercus civigulatus (Pyrrhocoridae : Hemiptera)
- Nymphs and adults desap on tender unopen bolls
- Tender bolls show microscopic punctures
- Boll opening erratic
- Bacterium, Nematospiora gossypii stains lint Yellow
- Seeds unfit for sowing and oil extraction
- Adult: Medium sized, black markings on hemielytra with a black spot – long antenna. Adults – hibernate in winter
- Life cycle : EP : 4-7 d ; NP : 50-90 d (5 instars)
Dusky cotton bug, Oxycarenus hyalinipennis (Lygacidae : Hemiptera)
- Damage at boll-bursting stage
- Nymphs and adults are dusky brown
- Desap seeds at boll burst in small groups
- Seeds shrivel, shrunken, Lint stained black
- Adult : Small, flat with dark brownish black body and transparent wings
- white eggs – laid in clusters of 2-10 inside half-opened bolls, on the bolls, flowers or buds.
- Nymphs : Five instars. Life cycle 30-40 days
Spotted bollworms: Earias vitella, E. insulana (Noctuidae : Lepidoptera)
- Incidence starts 40-50 DAS. Potential pest of cotton
- Bolls with irregular bore holes smeared with excreta,
- Dropping of bolls, irregularly bored Lint
- Larva bores tender shoot-causing dead hearts drooping and drying of shoot tips
- At square formation, bores squares causing flaring and dropping of squares
- Pupa: Boat shaped leathery cocoon on buds, bolls or debris
- Life cycle: EP: 3-4 d; LP: 10-12 d; PP : 7-10 d.
- E. vitella: Small moth forewings yellow with green band. Hind wings yellow / hyaline
- Larva: brown with white median longi stripe and no finger-like processes
- E. insulans : forewings – totally green
- Larva: more creamy with small finger – shaped processes (on 2, 3 Thorax and abdomen) and orange dots on prothorax
Pink Bollworm – Pectinophora gossypiella (Gelechiidae : Lepidoptera
- Damage: 85-100%
- Premature shedding of buds, bolls
- At flowering – Rosette bloom- Petals are webbed together without opening.
- Inside the Rosetted flowers yellowish white larva devours style, anthers and ovary
- Bore-holes will not be seen outside as the young larva enters the boll through the tip which heals up
- Premature opening of bolls exposing lint to saprophytic fungus – reducing ginning qualities
- Inside the bolls, seeds and locules are damaged
- larva bores adjacent seeds to form double seeds for hibernation
- Lint stained
- Larva: Young ones pale yellow , before pupation attain pink colour
- Pupate in soil among fallen leaves, flowers, clods.
- Moth: Small, active, dark brown, dull yellow or live grey with dark spots on forewing.
- Tender buds, bolls attacked, flaring squares
- Young larvae feed on foliage causing irregular holes
- On bolls, round holes are seen
- Larva cannibalistic
- Green larva thrusts – head alone inside tail outside
Stem weevil: Phempherulus affinis (Curculionidae : Coleoptera)
- Severe pest on summer cotton. Damage in young seedlings 60-80%
- Plants suddenly wilt and dry up.At collar region galls seen
- Plant tend to break at the collar region, Gall – result of phytotoxaemia
- Yellowish white grub / pupa or small brown weevil seen inside tunnels
- Adult, small snouted brown weevil. Grubs fleshy, yellowish white, feeding on tissues. Pupa : inside the chamber on stem
Semi loopers
- Larvae feed on foliage causing irregular feeding holes
- Crop becomes sickly with stunted growth with reduced squares, bolls, flowers
Anomis flava Medium, forewings reddish brown with brown spot and faint cross stripes. Males brighter. Larva: Green with 5 longitudinal stripes red prologs.
Acontia graellsi Medium, forewings lemon yellow with transverse brown streak and Larva: Green with brown horse-shoe shaped markings and black warts
Tarache nitidula Adult: White wings with dark markings. Larva: Dark brown
Leaf Roller : Sylepta derogate (Pyraustidae : Lepidoptera)
- Larva rolls the leaves and feed within leaves dry and drop, trumpet-shaped rolls
- Results in total defoliation
- Moth : Medium, whitish, yellow with brown wary markings
- Larva : Green, glistening, brist-moving scrapping and feeding leaves – sparse hairs. Pupa : Within leaf fold / debris in ground
Tobacco caterpillar: Spodoptera litura (Noctuidae : Lepidoptera)
