As long as the temperature within a grain bin or building where grain is stored remains above 50° F, the Indian meal moth can survive and reproduce. A typical life cycle (egg to adult) is completed in forth to fifty-five days. A potential for seven to nine generations per year exists; however, because of cool temperatures during the winter months fewer generations are usually completed. Under optimal conditions, the entire life cycle can be completed in approximately twenty-eight days. A mature female lays 100 to 300 eggs on food material, either singularly or in groups of twelve to thirty. Larvae begin to hatch in two to fourteen days, depending on environmental conditions. Newly hatched larvae feed on fine materials within the grain and are small enough to pass through a sixty mesh screen. For this reason, it is difficult to exclude larvae from most packaged foods and grain. However, larvae cannot chew through packages, so they must enter through a hole or at the seam. The larval stage lasts from two weeks to one year, and is responsible for grain losses. In grain, larval feeding is usually restricted to the top one to two inches. Large larvae feed on the grain germ. When mature, larvae spin a silken cocoon and transform into light-brown pupae. The cocoons and pupae can be seen on the grain surface and walls of grain bins. Adults emerge in four to thirty days, mate, and females lay the next generation of eggs. Adults live from five to twenty-five days.