Indian Meal Moths
The Indian meal moth has a wingspan of about 3/4 inch. The color of the outer two-thirds of the wings is bronze to reddish brown, while the part of the wings closer to the body is grayish white (the wing marking pattern allows the Indian meal moth to be easily distinguished from other household moths). The larvae (caterpillars) are about 1/2 inch long when mature. They are a dirty white color, sometimes exhibiting pink or green hues.
Indian meal moths are generally brought into homes by way of infested food packages. They are found primarily in kitchens and food storage areas. These insects feed on grain products. The larvae leave a silken thread behind wherever it crawls so that the surface of the food may become covered with webbing produced by the larvae. The adult moths are frequently seen in cabinets, kitchen pantries, on counter tops and around windows.
The larvae (caterpillar) of the Indian meal moth feed upon a wide range of foods. The most commonly infested foods include: coarsely ground grain (e.g. cornmeal) and cereal products, dried herbs and fruits, nuts, powdered milk, flour, spices, dry pet foods, and bird seed.
Life cycle and Reproduction
A female Indian meal moth can lay from 100 to 300 eggs during her lifetime. Eggs are laid either directly on food or in crevices adjacent to the stored food products. Within a few days the tiny whitish larva (caterpillars) emerge. Depending on the environmental conditions and the quality of the food source, it can take from two weeks to one year for the larvae to reach full size.
When mature, the larva spin a silken cocoon and transform into light-brown pupae. Adults emerge in four to thirty days, mate, and females lay the next generation of eggs. During this time the female may deposit over 300 eggs, laid either directly on food or in crevices adjacent to the stored foods on which they feed. Since the moths do not feed they usually survive little more than a week.
The Indian meal moth is considered a common pantry pest and is one of the more common moths infesting stored grains and grain products. In Utah it is not a major problem, but can be troublesome on occasion.