Rice Weevil (Sitophilus oryzae)

Rice weevils are pests of stored grain and seeds. Both grain and rice weevils penetrate and feed on the internal portions of whole grains during the larval (immature) stage, making early detection of infestations difficult. They are usually found in grain storage facilities or processing plants, infesting wheat, oats, rye, barley, rice, and corn. Although not often found in the home, sometimes they infest table beans, acorns, chestnuts, birdseed, sunflower seeds, and ornamental corn.

Identification:
Adult rice weevil, 2.5 - 3.5mm in length. Brown to black in colour and have four faint redbrown spots on the back of the abdomen. They have hard-shelled bodies that appear pitted or scarred with tiny holes. Weevils possess a long slender snout.

Biology:
Female rice weevils lay300 to 400 eggs, they drill a tiny hole in the grain kernel, deposit an egg in the cavity, and then plug the hole with a gelatinous secretion. The egg hatches into a young larva which bores toward the centre of the kernel, feeds, grows, and pupates. New adults bore emergence holes from the inside, then leave to mate and begin a new generation, the full life cycle requiring about 32 days for completion.

Control:
Infestations in domestic or food storage situations can usually be traced back to a cereal source. Since these beetles can infest so many types of grain products, inspect thoroughly. There may be several infested products, discard any food that is infested. Infested areas should be thoroughly vacuumed paying particular attention to cracks and crevices, contents of the vacuum cleaner should be disposed of in an outside bin. Store new food products in sealed glass or plastic containers. After cleaning, treat the infested areas using a residual insecticide labeled for crawling insect to ensure that all adult beetles and larvae have been killed.

Products to control Rice Weevil: