Their wings are uniformly gray. Egg-laying females infested seeds either while crops are in the field or in storage. Larvae tunnel into seeds, feeding on the germ and endosperm, and form silk tubes in which they pupate. Their life cycle is completed in about 5 weeks and up to six generations can occur annually. Night-active female moths lay eggs, singly or in clusters, on suitable larval food.
Caterpillars hatch from eggs and produce silken tunnels for protection while feeding.
Larval development varies in length with temperature and type of food material. Just before pupating, larvae leave the food source. Caterpillars can be found crawling on walls and ceilings searching for a place to spin a cocoon. Development from egg to adult takes from 27 to 305 days, and 7 or 8 generations can occur in a year. Caterpillars have chewing mouthparts.