Maize weevils

Family of Curculionidae, maize weevil (Sitophilus zeamais) is a small weevil about 2.4 – 4.5 mm in length with its head protruded into a snout or a distinct beak or proboscis. It is a major pest of stored maize in the tropics.

Pesticides for control of weevils are available, but the resource poor farmers of the developing world often cannot afford them. Sitophilus zeamais Motsch is virtually cosmopolitan throughout the warmer parts of the world, extending as far north as Joan and southern Europe.

Maize weevils are capable of flight, and in warm areas, they commonly fly to fields and infest corn before it is harvested. They can easily move form one lot of stored grain to another.

Eggs are deposited inside the grains, in small holes chewed by the female; each female may lay 300-400 eggs over a period of several weeks.

The adult maize weevil may remain inside the kernel for some time after eclosion but eventually emerges by chewing its way out. After emergence from the pupae, the adult eats through the outer layer of the grain leaving a roughly circular hole approximately 1.5 mm in diameter.

The weevils use their elongated snouts, which have jaws for digging into the grain, while the females use their snouts for digging hole into which they lay eggs.
Maize weevils