Indian Meal Moths at Home? Check the Bird Food

Pantry pests are the name given to insects, usually beetles and moths, which tend to infest stored food products. Many food-processing plants and supermarkets struggle with controlling these types of pests, but they can also become problems at home. One of the most commonly reported pantry pests in the United States is the Indian meal moth.

Indian meal moth adults are ½ inch long with a wingspan of 3/4 inch. They can be distinguished from other moths by their two-toned markings on their wings, which are whitish-gray closest to the head, and reddish-brown with a copper luster on the end of the forewings.

Indian meal moth close up

Indian meal moth. Photo by Jim Kalisch, UNL Department of Entomology.

Indian meal moth infestations are often brought home from infested products. When I want to catch a good moth infestation, I go to any big store that sells home and garden supplies and go directly to the bird seed.

The problem with bird seed is the way it is stored; It’s often packaged in extra large bags that have a tendency to rip and create spillage on the shelves, cardboard and floor. These bags of bird seed, which can include a variety of sunflower seeds, safflower, thistle seed, millet, whole and cracked corn are attractive to birds, rodents and insect pests.  Because they are difficult to handle and move, bags are are seldom rotated or removed for cleaning and sanitation. Older stock tend to remain in the area and pest populations can increase. Most people don’t think about it when they grab a bag of bird seed for their feeders, but if you are easily entertained by insects (like me), you could stop for a minute and watch the moths flutter about.

Indian meal moth in a store

Indian meal moth on the metal shelves in the bird seed aisle at a store. Photo by Jody Green, Nebraska Extension in Lancaster County.

Once you bring the bird seed home, the moths can infest other food products that you have in your home. The female moth will lay their eggs near a food source such as dry grains, nuts, dried fruit, cereals, chocolate, and spices. When the eggs hatch the larvae crawl into the food packaging. Adult moths are short-lived and do not feed, therefore damage to food product is done by the larval form.

Immature Indian meal moths are caterpillars that have a distinctly dark head capsule, three pairs of thoracic legs, and five pairs of prolegs on the abdomen. Indian meal moth larvae are sometimes mistaken for maggots, which are the larval form of flies. (Maggots lack a head capsule, are completely legless, and do not thrive in dried goods.)

Indian meal moth larva

Indian meal moth larvae. Photo by Jim Kalisch, UNL Department of Entomology.

The Indian meal moth larvae have chewing mouthparts, which allows them to gain access into unopened packages of food. During its larval form, it can appear to be yellowish, greenish, or pinkish in color depending on its food source.  It eats, grows and molts five times, growing up to 5/8 inch before it travels out of the product, leaving silken threads behind to where it will pupate and emerge as an adult moth.

Signs of Indian meal moth infestations in the home include:

1) Adult moths flying around inside the house, usually attracted to lights, fluttering around screens at night

2) Silken threads and webbing on/in food products, packaging, storage shelving, cupboards, walls and ceilings

3) Larvae or caterpillars crawling in the food products that contain flour, cereal, stored grains, chocolate, nuts or dried fruits

Indian meal moth cocoon

Indian meal moth cocoon found in the folds of the packaging from a bag of organic flour. Photo by Jody Green, Nebraska Extension in Lancaster County.

Prevention and sanitation is your best protection against pantry pests. Here are some ways you can prevent infestations in the home, minimize wasted food and save money:

  • Before purchase, check for rips or tears in packaging and other signs of infestations.
  • Avoid buying in bulk and storing large quantities of products in the pantry.
  • Store products in air-tight, insect-proof containers. This includes the garage.
  • Use the oldest products first to ensure freshness and proper stock rotation.
  • Store infrequently used products in the refrigerator or freezer.
  • Clean up spills and crumbs in food storage areas so not to attract pests.
  • Vacuum cracks and crevices where insects can hide and grains can accumulate.
  • Dispose infested foods in trash and put outdoors.
  • Non-food items that may be infested with include dried flowers, museum specimens and spices.
  • Indian meal moth have been known to infest candy bars and baked goods in vending machines. Inspect before you bite into your snack!
IMM stuck to Pheromone traps

Pheromone traps use a natural chemical compounds from female moths to attract males to a sticky glue board. Photo by Jody Green, Nebraska Extension in Lancaster County.

Treatment strategies for Indian meal moth do not include insecticide use inside the home. A thorough inspection is necessary to locate and eliminate the source of the infestation to provide a long term solution. Indian meal moths have a wide range of food sources so inspections are not limited to the pantry, but should be done in the the garage, storage areas and home decor. There are pheromone traps available that attract the male species to a sticky glue board, but these are preferred as a monitoring tool rather than a control method.

Many people believe the chill of winter will get rid the home of all pests, but pantry pests are one that can occur year round in heated buildings. Keep your eye on your food and don’t share it with pantry pests.

Stay calm and respect the critters,

Jody

 

 

 

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