Most recently reviewed by: Pat Porter & Janet Hurley (2018)
Common Name(s): Indian Meal Moth, Indianmeal moth
The wings of these moths are pale gray, but the outer two-thirds of the front wing is covered in reddish-copper scales. The moth is 1/2 inch long and has a wing span of 5/8 to 3/4 inches. Mature larvae are cream colored, but the color may vary depending on the food source. The larvae are 1/2 inch long. they produce silken threads that are visible on the food source.
Origin and Distribution
This insect is found in a wide range of climates in stored products and food storage facilities around the world. It is a pest of flour mills, processing plants, dried fruit and on the surface of all types of grains.
Adults are nocturnal, able to fly and are attracted to lights.
Habitat & Hosts
Moths and larvae are found in food storage areas. They attack grain and grain products; milled or ground cereal such as wheat, graham flour and cornmeal; and starchy processed products like cakes, pasta, dog food and rodent bait. They also like nuts, dried fruit, some spices and bird seed. The larvae spin silk as they feed and feed in or near a tunnel-like case of frass and silk, producing a lot of webbing in the infested material
There are four life stages; egg, larva, pupa and adult. In summer the life cycle takes about 4 weeks.
ManagementIf you live in the State of Texas, contact your local county agent or entomologist for management information. If you live outside of Texas, contact your local extension for management options.
In commercial or on-farm grain storage, take regular monthly samples and look for webbing and moths near grain surface.
Pheromone traps are available for monitoring and control both in commercial grain storage and in homes and restaurants.
The first step in controlling pantry pests is to find and eliminate infested items. Often all that is needed to solve the problem is to remove an infested package of flour, macaroni, or cake mix. But finding the source of an infestation is not always easy. Infested packages are usually the oldest, most difficult to reach foods in the pantry. Even unopened containers may be infested; some pests can easily penetrate plastic, waxed paper, and cardboard containers. Before buying an item in the store, check that the bag or container is well sealed and undamaged.
Good sanitation is important. Infestations often start in pet foods, spilled grains, or other foods. Clean up spilled food promptly. Discard old packages of grain and pasta. Vacuum and clean pantry areas periodically to remove spilled foods. Remove and clean underneath shelf paper. Caulk around pantry edges and in cracks and crevices to reduce areas where spilled food may collect.
Most pantry pest problems can be prevented by using all dried food within 2 to 4 months of purchase. Spices and other products kept for longer periods should be sealed in airtight containers.
Pet food can be a special problem. The most commonly infested pantry items are birdseed and dog and cat foods. Store pet foods in well-sealed plastic buckets or storage containers and use them promptly. Clean the containers thoroughly before refilling them with food.
Occasionally, mice or other rodents can cause a persistent beetle infestation. Hoarded seed and grain in abandoned rodent nests can support a small population of pests. Old rodent bait that contains grain also can harbor insects. When controlling rodents, prevent insect problems by placing the bait where it can be retrieved and discarded after the rodents are controlled.
Heat or cold treatments can eliminate pests in some food items such as pet food, bulk grains and beans, and home-grown dried beans or peas. Put the product in the oven at 130 degrees F for 1 hour, or in the freezer for 7 to 14 days. To prevent an infestation, store foods that may attract pantry pests in the refrigerator or freezer.
On rare occasions, insecticides may be needed to control difficult infestations. Insecticides can reach inaccessible areas that cannot be easily cleaned; they can also help reduce heavy pest infestations more quickly.
Insecticide sprays may be applied to crevices and void areas around cupboards, drawers, and pantries. Before spraying, remove all food products, utensils, and containers from the treatment area. Allow the spray to dry before placing clean shelf paper on the shelves and returning food, utensils, or containers to the pantry.
Insecticide products that are labeled for use in food- storage areas generally contain ingredients that are short-lived and relatively safe to use in the home. Active ingredients of these products include pyrethrins, resmethrin, allethrin, and tetramethrin.
For areas where long-term residual control is de- sired, look for products containing synthetic pyrethroids, such as permethrin, esfenvalerate, cyfluthrin, or bifenthrin. Aerosol fog products can temporarily suppress infestations of flying insects, but these fogs will not kill pantry pests in food containers or protected locations.
Before using an insecticide, always make sure that the label says that the product may be used indoors and in kitchens. Never spray food, dishes, utensils, or cooking items with pesticides.