Life Cycle

Oviposition takes place in the night, female deposits 2-3 eggs on leaf bract, flower bud or tender leaf, usually on the under surface. Fecundity is 200-400 eggs per female. Eggs are deep sky blue or greenish crowned and sculpted on the surface. Incubation period is 3-5 days. Full grown larva is about 2 cm long, brownish with white patches on the dorsal side of the body. There are 6 larval instars and the total larval development takes 12-18 days. Pupation takes place on the plant or rarely in the soil among fallen leaves. A boat-shaped grayish silken cocoon is constructed for pupa formation.

Nature of Damage

Young larvae attack growing shoots leading to drooping and withering of the top shoot. In later stages buds, flowers and bolls are also damaged. Flower buds open up prematurely causing “flared squares”. In damaged bolls pulp is eaten up and lint is stained.

The attack of okra follows a similar pattern to that of cotton. Terminal shoots are bored initially, with attack moving to flower buds and fruit as they appear. In severe tunneling the top leaves wilt and the whole apex of the plant droops, hampering further growth. Secondary branching may occasionally occur. When fruiting starts, larvae move to flower buds, tiny fruits, and eventually the mature pods. Severe attack causes the shedding of flower buds and reduced yield. When attacking the fruit, the larvae feed on the milky seeds and other contents of the pod, leaving excrement-filled tunnels.