Damage caused by cotton bollworms
Larvae of cotton bollworm generally bore at the base of the flower buds and feed on the content of developing buds. These larvae also feed on the leaves and young shoots of cotton. Mature larvae then bore into both young and maturing cotton bolls. Only 2- 3 larvae of cotton bollworm are enough to destroy all the cotton bolls on the infested plant within a few days. These severely damaged cotton bolls fall off the plants that leads into the serious losses of cotton crops.
Facts (show all)
- +Common names
- Cotton bollworm
- +Scientific name
- Helicoverpa armigera
Adults: Adult moths of cotton bollworm are yellowish brown to orange brown in color with a black spot on each forewing. Handwings creamy white with dark brown bands on the outer margin. Each forewing has a black spot on their tips with silver scales near wng fringes.
Eggs: Eggs of cotton bollworm are yellowish white to brown in color.
Larvae: Mature larvae of cotton bollworm are greenish blue to dark brownish red with brown lateral and distinct dorsal stripes.
Pupae: Pupae of cotton bollworm are dark brown in color.
Cotton bollworm develop through four life stages including eggs, larvae, pupae and adults (moths). Cotton bollworms overwinter as pupae in the soil. Adult moths emerge from pupae in late May through early June. After mating, female moths lay eggs singly on the leaves and near the flower buds of cotton. For egg laying, females generally prefer hairy leaf surfaces than the smooth leaf surfaces. The eggs hatch within 3 days into small larvae that feed on the cotton leaves, shoots and bolls. Under favourable conditions, the cotton bollworms complete their life cycle within a month and 2-5 generations in a year.+ Organic Control of cotton bollworms
- Following beneficial wasps are used for organic control of cotton bollworms
- Trichogramma brassicae
- Trichogramma pretiosum
- Trichogramma minutum
- Trichogramma platneri