Life Cycle

The time of appearance of this pest and the details of life history varies in different places depending upon the climate and planting time of the sugarcane. It may appear in February but the general time of appearance in Indian conditions is March-May. Female lays 300- 400 eggs. The eggs are laid in the clusters of 10-30 eggs on the under surface of the leaves by the side of the mid rib. The eggs are creamy-white in colour and has scale like appearance. The eggs hatch in about a week time and the larvae at first feed upon the leave epidermis and then with the help of their cutting and chewing mouth parts bores into the stem from near the base of the cane plant.

The larvae are dull white in colour with a number of brownish-red longitudinal stripes on the back. A fully grown larva measures about 2.5 cm in length. The significant characteristic feature of the larvae is that they bore in and bore out a number of times, either in the same stalk or in the neighboring ones. The larval period lasts for about three weeks, after which the larvae pupates in the tunnel within the sugarcane stalk where they had been feeding before. The pupal period lasts a little more than a week after which the moth emerges out from the exit hole prepared by the larva before pupation. Four to five generations are repeated in an year. During winter months the larvae undergoes hibernation.

Nature of Damage

This pest is mainly injurious to the younger plants, before internode formation. The damage is done by the caterpillars which bores into the stem and feed the soft tissues. While feeding the caterpillars moves upward as well as downward and may reach the roots, which eventually dries forming ‘dead heart’. The dead heart can be easily pulled out. It emits an offensive odour. Infestation of internodes makes the matured cane hard, devoid of juice which becomes difficult to mill. Tunnels are also formed within the shoot as a result both quality and quantity of the juice is reduced. Damage done by this pest may be upto 50%.