Potato Moth

Potato Moth (Phthorimaea operculella) adults are about 12 mm across the outspread wings, and have brownish grey forewings with tiny dark scattered markings. A fringe of fine hairs borders the pale-cream hind-wings. They fly readily, and deposit minute white eggs on the plants or tubers. On leaves, the eggs are usually laid singly on the under surfaces; on tubers, they are laid in groups around the eyes or surface scars. Each moth can lay up to 100 eggs in two weeks. Incubation requires from a week in summer to several weeks in winter. The larvae mine the leaves, stems and fruit. Young plants can suffer tip death from boring larvae. Larvae can enter through the calyx end of the fruit, or where two fruit or a leaf and fruit touch, obscuring damage beneath. Damage is often significant and tends to be more serious if other susceptible crops are grown nearby.