Foreign Grain Beetle

Foreign Grain Beetle

The foreign grain beetle received its name from being a “foreign” pest in grain storage facilities. These beetles are very common and will feed on damp or deteriorating materials. Foreign grain beetles are found throughout the world, including the United States and Missouri.

Pest Identification

The foreign grain beetle is a small insect; adults can grow to be 1/8th of an inch in length. They are reddish-brown in color and when looking at them from above, the shell directly behind their head has rounded projections coming off the front corners. The larvae of the foreign grain beetle also grows to be about 1/8th of an inch in length and they have an elongated body and are whitish-yellow in color.


The adult female grain beetle lay their eggs on food materials. The eggs hatch after about 4 days and the larvae feed and molt 4-5 times over a period of 11-19 days. They then enter into a pupae stage for 3-5 days from which they emerge as adults. They entire life cycle from egg to adult takes approximately 3 weeks.


Foreign grain beetles are found most often not in grain storage buildings, but in areas of new construction. This is because the building materials (sheetrock, plaster, caulking, plywood) used to create the structures tend to be damp and harbor trace amounts of mold until they completely dry out over time. Once the grain beetles enter, they stay and feed on other items that may include cereals, grains, spices, dried fruits, and seeds.


The best way to prevent foreign grain beetles is to keep moisture levels reduced on your property, whether it be new construction or an older home or business with moisture problems. Use dehumidifiers, air-conditioners, and fans to reduce moisture levels in crawl spaces, basements, and attics. It is also a good idea to store cereal, grains, and other stored products in dry areas in plastic or glass containers with sealed lids. Inspect dry goods before purchasing them and don’t purchase any products that have tears or holes in the packaging.


The most effective way to control foreign grain beetles is through the help of a professional pest control expert. At Rotter Lawn & Pest Solutions a trained technician will inspect your home or business in search of areas of moisture that could be attracting foreign grain beetles. We can then provide control through our home and commercial pest control services and offer suggestions for how to reduce moisture levels within your home or business.

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