Cotton - Pink boll worm
Description
The moth is small (8-15 mm), greyish and inconspicuous. Eggs are laid on fruiting parts if available and the yellowish larvae (brown head) feed in either the flower or young bolls (the entrance hole is often too small to be seen easily). As they grow they become more pinkish (two pink bands on each segment). The light brown pupa is formed in dried bolls, leaf trash or in the soil.
Damage
Early damage is manifested as flower resetting caused by larvae spinning together developing flower petals. Entry holes in the fruits are rarely visible; larvae mine through the seed and the developing lint causing incomplete boll split and rotted lint and seed.
Life cycle
300-500 eggs are laid singly by each female following a 3-4 day pre-oviposition period. The eggs are often laid behind bracts and in sheltered or hidden places on the fruiting body. Eggs hatch 4-8 days later and young larvae must feed immediately in order to survive. After 14-21 days the 4th instar larvae pupate inside bolls or in ground litter, but later in the season frequently spin pairs of damaged seeds together to form a diapause cocoon. Unless entering a state of diapause, pupation lasts for 12-14 days thus the total life cycle may last four to six weeks. There are 4-6 generations a year.