Cotton - Red boll worm
Description
The egg is bluish changing to grey before hatching. The body of a newly batched caterpillar is pale cream or greyish-white. Characteristic red markings appear in the second instar and it is this deep red color which makes them easily distinguishable. Caterpillars grow to a length of 25-30 mm. Pupae are pale yellowish-brown to brown, stout bodied, humped, 14-17 mm long.
Adults have variable color forewings generally with a reddish central area is reddish. The hindwihgs, like the body, are silvery cream.
Damage
Young caterpillars bore into flower buds and eat them, while older caterpillars penetrate bolls and hollow them out. One or more tunnels are often found in older bolls and excrement is usually present in the tunnel or between the boll and the bract.
Life cycle
Adult moths are sexually mature upon emergence, and mating and oviposition may well occur during the first night. Each female can lay up to 500 eggs, placed singly on buds, shoots or leaves. These hatch after 4-10 days, and the emerging larvae immediately start tunneling. After passing through five instars in 2-3 weeks the larvae pupate and after a further 2-3 weeks adults emerge.