| Both sawtoothed grain
beetles and their close relatives, the merchant grain beetles (Oryzaephilus
mercator (Fauvel)), are common stored-food product pests that infest
cereals, corn meal, cornstarch, popcorn, rice, dried fruits, breakfast
foods, flour, biscuit mix, rolled oats, bran, macaroni, sugar, drugs, spices,
herbs, candy, dried meats, chocolate, bread, nuts, crackers, raisins, dried
dog and cat food, and other foodstuffs, rendering them unusable.
The beetles are capable of chewing into tightly sealed packages, including
unopened paper and cardboard boxes and cellophane, plastic, and foil wrappings.
They do not bite or sting, spread disease, or damage structures or furniture.
Adults of both species are flattened, reddish-brown beetles around a tenth
of an inch long. They have six sawtooth-like projections on each
side of the prothorax (the middle part of the body, between the head and
the wing covers), and the wing covers (elytra) are longitudinally grooved.
Under magnification, the sawtoothed grain beetle is seen to have a temple
area (the region behind the eye) about half as long as the eye. The
temple area of the merchant grain beetle is much smaller. The sawtoothed
grain beetle cannot fly, but the merchant grain beetle can fly. The
sawtoothed grain beetle prefers cereal-based products, feeding on finely
divided food particles, rather than whole grains. The merchant grain
beetle prefers nuts, seeds, and dried fruit. |