Cotton - Leaf worm
Description
Leaf worm is a polyphagous species. The adult lays clusters of several dozen eggs under the leaves. The neonatal caterpillars remain grouped together and feed on epidermis for several days before dispersing and spreading to other parts of the foliage. At the end of the larval period, they spend the day in the soil, and are mainly active at night. Caterpillars are pale green when young but become brown to black.
Damage
Newly hatched larvae produce many small "windows" near their site of hatching, later causing a "shot hole" effect and eventually leaf skeletonization.
Life cycle
Eggs are laid in masses at night, one female producing up to 2000 eggs in her life. Under optimum conditions, the eggs hatch in 2-6 days to produce gregarious larvae. These pass through six larval instars in 2-4 weeks during which time they disperse. Pupation takes place in an earthen cell just below the soil surface and after 6-11 days, adults emerge.