The Lesser Grain Borer (Rhyzopertha dominica) is one of the most economically important stored-grain pests in the world and a major pest of stored wheat, corn, rice, barley, and other whole grains in Arizona. Adults are small (1/8 inch), cylindrical, dark reddish-brown to nearly black beetles with a distinctively hooded thorax that completely conceals the head when viewed from above — giving them a characteristic headless appearance. The wing covers have rows of fine punctures. Adults can fly and are attracted to light. Both adults and larvae are primary pests — both can attack whole, undamaged grain kernels. Adults bore into grain kernels from the outside, while larvae develop inside the kernel. This dual feeding by both life stages makes the Lesser Grain Borer particularly destructive. Heavily infested grain develops a distinctive sweet, musty odor caused by the beetles' secretions — a useful diagnostic sign. In Arizona's warm climate, the Lesser Grain Borer is extremely well-adapted and can complete a generation in as little as 4 weeks during summer, making it one of the fastest-reproducing stored-grain pests in the state.