Back to: Granary Weevils
Granary weevils are considered the most economically important pest of whole grain throughout the world. Weevils are basically beetles with snouts. Well, not all weevils have a noticeable snout, but the rice and granary weevils do and that’s what makes them easily recognizable. The snout extends from the front of the head downward. At the tip are found the weevil’s mouthparts. Both the Rice and Granary weevils closely resemble each other. They are both 1/8th to 3/16th of an inch long, and dark to reddish brown in color. The main visible difference is that each weevil has pits on the prothorax (the area just behind the head). Rice weevils are round in shape, while Granary weevils are oval. Rice weevils can fly, while the Granary weevil cannot. Even though these weevils are present throughout the world, the Granary weevil is found more in the Northern states, as it can withstand colder weather. The Rice weevils need it warmer; therefore, they are more prevalent in the South. Another interesting fact is that these weevils play dead for several minutes when disturbed. They do this as a defense against would-be predators. The female chews a hole into a kernel of grain, then deposits an egg in it. She seals the hole and moves to the next kernel. Her life span is 4 to 5 months, and she’ll lay approximately 300 to 400 eggs during that time. As a general rule, only 50% of the eggs ever hatch. The larvae live inside the kernel and eat it till they become mature. This can be in as few as 26 days under ideal conditions, but usually takes longer. When pupation is done, the adult weevil chews a hole in the kernel to exit through, but does not seal it up. Both weevils are internal feeders primarily feeding on whole grain, but they have been found in macaroni, spaghetti noodles, and pasta that has become old and caked. Inspection and control tips are the same as mentioned before. Just be sure you are thorough.