Sawtoothed Grain Beetles

Active Seasons


Appearance and Size Facts

  • Reddish-brown in color
  • Flattened body and have six sawtooth-like projections on each side of the prothorax
  • Size Very small, roughly 1/10 inch long
  • Scavenger and cannot fly
  • Prefer cereal based products but have been known to invade a variety of food

Schedule a FREE Inspection

Behavior and Habitat of Sawtoothed Grain Beetles

The Sawtoothed grain beetle is a scavenger and can not fly. Adults and larvae are external feeders, feeding on finely divided food particles and not whole grains. Large populations of this beetle can develop quickly, forcing adult beetles to seek new food sources. They have been known to invade every package or food stored near an infested food product.

Sawtoothed grain beetle adults usually live about 6 to 10 months, with some living as long as 3 years. Females usually emerge in April and lay an average of 300 eggs. Egg laying begins about 5 days after emergence and continues up to 3 to 4 weeks. Eggs hatch in about 8 days, larvae mature in 37 days, and pupa about 67 days. They prefer cereal-based products.

The Sawtoothed grain beetle is common in stored-food products such as cereal, cornmeal, cornstarch, popcorn, rice, dried fruits, raisins, flour, pet foods, bran, macaroni, sugar, and bread. They are capable of chewing into unopened paper or cardboard boxes, through cellophane, plastic, and foil wrapped packages. Once inside, populations build up rapidly often spreading to other stored foods and into food debris accumulated in the cupboard corners.

Signs of Infestation of Sawtoothed Grain Beetles

Look if there are small beetles in pantry products or crawling on surfaces like counters or shelves.

Tips for Prevention of Sawtoothed Grain Beetles

Discard any infested foods, vacuum pantry shelves, cracks, and crevices and make sure to dispose of garbage and vacuum bags outside, away from the home, wipe shelves with white vinegar.

Sawtoothed Grain Beetle Gallery