The rice weevil (Sitophilus oryzae, S. zeeamais) infests maize, wheat, oats, barley and other grains. It may also infest other hard foodstuffs such as macaroni and spaghetti. Infestation usually occurs after harvesting, but on the north coast maize may be infested in the field. In summer, growers and storers of grain must take steps to prevent an infestation or control it.

The female weevil lays an average of 400 eggs. Eggs are laid singly in excavations made, usually, in the soft starch of the grain. On hatching, (3-4 days in warm, about 9 in cold weather), larvae usually bore to the centre of the grain, but occasionally tunnel near the surface. After about five days in the pupal stage, they become adults, and eat themselves out of the grain. This species can fly.

Development from egg to adult takes about four weeks; from then to laying eggs about one week in summer; in colder conditions, the life cycle may be considerably prolonged. There may be six or seven generations a year.