Cotton leaf roller (Haritalodes (Sylepta) derogata)
The moths are about 15 mm long with a wingspan of 25-30 mm. They are yellowish-white with black and brown spots on the head and thorax and a series of dark-brown wavy lines on the wings. Caterpillars are dirty pale green and semi-translucent and up to 30 mm long when fully grown. Moths lay eggs on the underside of leaves. Young caterpillars feed initially on the underside of leaves, but older caterpillars spin or roll leaves together, and eat the leaf margins, causing the leaves to curl and droop. They pupate in the leaf roll or in debris on the ground.
The leaf roller is a common pest, which may cause considerable local damage. In extreme cases, the cotton plants may be almost completely defoliated, as a result the growth of the plants is stunted, and the bolls ripe prematurely leading to yield reduction.
- The leaf roller is usually controlled by natural enemies, particularly parasitic wasps, spiders and praying mantis.
- Removal and destruction of eggs, caterpillars, pupae and rolled leaves help to reduce damage.