Female sawtoothed grain beetles 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. D.C. Merchant grain beetles lay an average of 200 eggs over 28 to 42 days, requiring about 35 days to complete the life cycle. There may be as many as 6 to 7 generations under warm conditions of 85 degrees F to 95 degrees F and 70-percent relative humidity, with fewer generations throughout the winter months.
Adults remain active and feed.
The sawtoothed grain beetle prefers cereal-based products, whereas the merchant grain beetle prefers nuts, seeds, and dried fruit. The simplest and most effective control measure is to locate the source of infestation and quickly get rid of it. Use a flashlight or other light source to examine all food storage areas and food products carefully. Dispose of heavily infested foods in wrapped, heavy plastic bags or in sealed containers for garbage disposal service, or bury deep in the soil if permitted, practical, and regulations allow. If you detect infestations early, disposal alone may solve the problem.