Adult. It is found in granaries, warehouses, and especially flour mills. Since it does not damage whole grain, it is regarded as a secondary pest.
The adult female may lay over 400 eggs in a lifetime. The small white larvae feed for a few weeks and then transform to pupae. At first white, the pupae gradually change to yellow and then brown as they complete their transformation to adults. A generation may be completed in as little as 6 weeks, but cold weather greatly prolongs the cycle. A near relative, the equally destructive red flour beetle, is often mistaken for this insect.
