IdentificationThe adult rice weevil is 2.5 - 3.5 mm long and has a slender, hard-shelled bodies that appear pitted or scarred with tiny holes. They are brown-black in color and possess a long slender snout. Rice weevils have four faint red-brown spots on the back of the abdomen.
DescriptionRice weevils are pests of stored grain and seeds. The adults can feign death by drawing up their legs close to the body, falling, and remaining silent when disturbed. Emergence holes of the rice weevil are smaller than those of the granary weevil, and tend to be smooth and round. There is generally no external evidence that the larvae have been eating and growing inside the seed until after about one month when the adult weevil chews through the seed coat and emerges. The adults live 3 to 6 months, infesting grain in the field. The egg, larva, and pupa stages of these weevils occur in the grain kernels and are rarely seen. Females drill a tiny hole in the grain kernel, deposit an egg in the cavity, then plug the hole with a gelatinous secretion. The egg hatches into a young larva which bores toward the center of the kernel, feeds, grows, and pupates there. New adults bore emergence holes from the inside, then leave to mate and begin a new generation. Female rice weevils lay between 300 to 400 eggs, with the life cycle requiring about 32 days for completion. Two larvae can develop in one wheat kernel.