[Pest Profile] Saw-Toothed Grain Beetle

Description

Adult saw-toothed grain beetles are small, slender, dark brown, flat insects about 1/8-inch long. Their most distinguishing characteristic is the six saw-like teeth found on either side of their pronotum (first segment behind the head). The larvae are yellow-white and about 1/8-inch long. They have three pairs of legs and a pair of false legs on the abdomen.

Biology

Over a four- to five-month period, females deposit 45 to 285 shiny white eggs in cracks or crevices in the foods they are infesting. They molt two to four times, and the life cycle (egg to egg) usually requires 30 to 50 days, although it may take as long as 375 days. There can be six to seven generations per year.

Habits

Saw-toothed grain beetles feed on a wide variety of stored products including flour, bread, breakfast cereals, macaroni, dried fruits, nuts, dried meats, sugar, dog food and biscuits. Since these beetles are flat, they easily hide in cracks and crevices and often penetrate poorly sealed packaged foods. Larvae feed on the same materials as adults. These insects can develop large populations in seldom-used stored materials, such as flour.

Control

The first step in effective saw-toothed grain beetle control is to find, remove and destroy all infested materials. The entire storage area should be vacuumed thoroughly to remove flour and other food materials from cracks and crevices. These materials can support adults and larvae. Infested stored products also can be sterilized with heat or cold. The surfaces, cracks and crevices, and other potential harborage areas for these pests can be treated with residual insecticide sprays or dusts. The application of these materials also helps to control adults that crawl into storage areas and serve as potential reinfestation threats. Sanitation is important in all grain storage or processing facilities to keep potential breeding sites to a minimum. Heavily infested materials may need to be fumigated to achieve control.