The Indian meal moth has been called the number one pest when it comes to insects in our kitchens and pantries. These moths commonly find ways into our homes, either from outdoors or through purchased food goods and then easily spread into our cereals, pasta, pet food, dried foods, nuts, grains and other dried goods. Let’s take a close look at the complete life cycle of the Indian meal moth from egg to larva and pupa to adult. Adult female Indian meal moths will lay eggs that are less than half a millimeter in length. Using her antennae in the same way that people use their noses, the female moth follows odors to find food and will then lay her eggs singly or in groups on or very near that food. Within 2 to 14 days after being laid, the larvae begin to hatch from their eggs. The larvae are so small at this point that they can easily enter pinholes in food packages or they can crawl up and around the threaded lids of some plastic food containers to gain entrance to the food inside. The larvae begin to feed within a few hours of hatching. Hardened pincers otherwise called mandibles can break off food particles that are chewed up and swallowed. The larvae are the only stage of this insect that consumes food. The adult stage does not eat. As the larvae crawl and feed, they leave a trail of silken thread that originates from a point beneath their mouths. Over time, these threads can create layers over their food and in other areas where they crawl. The layers act like blankets that protect them from predators such as birds and parasitic wasps. The layers also insulate them from cold and dry environments. As the moths feed and grow in size, they molt or shed their old skins and become a little larger each time. Indian meal moth larvae will molt between five to seven times. Depending on their food source, temperature and other environmental conditions, the larval stage can be as short as two weeks or as as long forty weeks. As the larvae mature they will grow to a length of 12 millimeters at which time they prepare themselves for pupation. Some larvae will gather food and frass to create a protective cocoon around itself while others will bypass a cocoon and go right into the pupal stage. The larva seen here is borrowing parts of a cocoon from another Indian meal moth larva to use on its own cocoon. Here the larva puts the final touches on sealing itself off from the outside world. As time progresses the larva will turn into a pupa and begin to darken in its final preparation to emerge as an adult moth. After a minimum of two weeks the moth pupa is ready to break free from its shell. It pops open a small flap near its head and begins to wriggle and writhe its way out of the pupal case. Once free of its confines, the newly emerged moth pumps up its wings while they still remain soft. Slowly the wings fill out until the point where they are fully expanded and the moths are ready to fly. Within 24 hours of emerging as an adult, Indian meal moths begin to search for a mate. The female begins the mating process by lifting her abdomen and extending a pheromone gland at the very tip that sends her pheromone into the air currents around her. Watch closely and you can see this process unfold. The adult male moth has receptors on his antenna that picks up her pheromone The excited male follows the pheromone scent directly to the female. As part of the mating process, the male has his own pheromone scent glands on the front edge of his wings. As he approaches, he rapidly fans his wings, pushing his pheromone forward to the female. If the female likes the combination of pheromone and tactile cues from this male She will turn 180 degrees to confirm him as a mate. The male pheromone acts like an aphrodisiac that both calms the female and causes her to extend her abdomen. As seen in the upper left, the male has two claspers at the end of his abdomen. The male uses his claspers to latch on to the female and mating begins. This entire process happens only over a few short seconds. A single female can mate with up to five males. Within 48 hours after mating the females begin to lay fertilized eggs The adult moths only live seven to ten days during which time the females can lay several hundred eggs on or near the food we eat. Indian meal moths have become experts in taking advantage of the environments that people create. Knowing more about their complete life cycle helps us find ways to eliminate this invasive pest from our kitchens and pantries.