Order: Coleoptera

Family: Cucujidae

The Merchant Grain Beetle and the Saw-Toothed Grain Beetle are very similar in appearance and habit. Typically, the difference is only found under a microscope. Although both pests can be found worldwide, the Saw-Toothed Grain Beetle is more common in upstate New York.

Description: Adults are approximately 1/8 inch in length. Their bodies are flat and dark brown in color. Both species have six saw-like teeth on each side of the prothorax (the middle section of their body).

Biology: Females will lay up to 200 eggs in small clusters in food materials. These eggs are white, shiny and hatch in just a few days. The entire life cycle (egg to egg) is usually just 30 days. However, depending on environmental conditions, the cycle may take longer. There can be as many as seven generations per year.

Habits: Adult Merchant Grain Beetles can fly and are attracted to light, while Saw-toothed Grain Beetles do not fly and are not attracted to light. Both beetles have a flat body which enables access through tiny cracks and crevices including food packages with imperfect seals. The Merchant Grain Beetle is generally not found in grain kernel products, preferring processed foodstuffs such as nuts, cereals, and cake mixes. The Saw-Toothed Grain Beetle does extensive damage to grains and other food products including: cereals, bread, macaroni, dried fruit, sugar, chocolate, and nuts.