Killing a Grain Beetle with Household Items

Grain beetles are commonly found in the pantry, feasting on grain products, nuts, dried fruits and pet food. When spraying insecticide is not desirable, eliminate these pests with household items.

Identification and Detection

The saw-toothed grain beetle and merchant grain beetle are similar in appearance, requiring the same treatment for elimination. Therefore, differentiating between the two is unnecessary. Both beetles are small, flat brown beetle, about 1/10 inch in length. They both have six teeth along each side of their middle section (the thorax). During their larval and adult stages they feed mostly on grain products, although they also can be found eating coconut, dried fruits, nuts, dried fruits, bird seed and other food products. The eggs are commonly laid in food stuff, and once they hatch, they will very quickly begin moving around and eating. The average grain beetle lives between 6 and 10 months; however, they have been known to live up to 3 years or so.

Once you find infected food products, seal it up in a bag, and remove it immediately from your home. If you can catch these beetles before they have spread throughout your home, the elimination of them may be as simple as tossing a few infected food items out the door.


Prevention is the best cure. Follow these tips to prevent these pests from infesting your home:
  • Don’t leave bags of food unopened in your shelves or pantries
  • Store everything in containers with lids that seal.
  • Store flours and other similar food materials in the freezer.
  • When shopping, inspect food products for broken bags or containers because it is the most common way grain beetles are brought into your home.
  • Don’t mix old food with new food in containers.
  • When refilling an old container with a new product, clean it out thoroughly first.

Elimination by Freezing

Grain beetles can be killed by freezing below 5 degrees Fahrenheit for 2 to 3 days. In temperatures, below 50 degrees, they will go into “hibernation,” unable to move around. Killing them, however, requires a couple days below 5 degrees F. They can then be removed from the material they have infested using a sieve. Eggs can last for a couple weeks in freezing temperatures. To insure that eggs are killed, freeze your materials for 3 weeks are longer.

Elimination by Heating

Another option for elimination is extreme heat, about 120 degrees F for about 2 hours. To kill eggs, larvae and adults, spread suspected material thinly in an oven, setting about 180 degrees F. Stir the material frequently. The longer the oven is on, the higher the temperature will rise, so check with a thermometer to insure that the temperature keeps about 120 degrees. Cracking the oven door when the temperature begins to rise can help maintain the proper temperature. Dried fruit can be freed of the infesting beetles by placing them in boiling water for a minute. Keep the fruit out to dry before storing again.

By following these suggestions, grain beetles can be eliminated without using insecticide.