Kitchen moths: Winged invaders in kitchen-land

Little, tan moths are a common thing to find in kitchens during the winter months.

Indianmeal moth adult. Photo credit: Whitney Cranshaw, Colorado State University, Bugwood.org
Indianmeal moth adult. Photo credit: Whitney Cranshaw, Colorado State University, Bugwood.org

“I have little, tan moths flying aimlessly around my kitchen. How could they be coming in my house now when it is snowing, and what are they doing?” This is a familiar question many Michigan State University Extension horticulture educators and Master Gardener hotlines across Michigan have received this time of year. These callers are not experiencing an invasion of strange snow moths. The moths are already living indoors and enjoying the bounty of food found in the kitchen. There are two kitchen moths that can be feeding on a number of food products found in almost all kitchens: the Indianmeal moth, the more common species, and the Mediterranean flour moth.

They feed in a number of food products that are not refrigerated, canned or in airtight containers. Their food choices include grain-based foods like corn meal, pancake and muffin mix, flour, rice, barley, cereal, oatmeal, pasta, unpopped popcorn, corn starch, dry bread crumbs and instant mashed potato flakes. These moths prefer finely ground grains or little pieces because they are small larvae when they are feeding. They could also be found in dried fruit and nuts. Often, dry pet food and birdseed are how they make it into the house. Spices like paprika, spice rubs and red pepper wreaths, chocolate and powdered milk can be targeted. Sometimes they are feeding in grain-based rodent baits tucked away from sight.

The Indianmeal moth has about a half-inch wing span and is silvery-beige with the lower portion of the wings a coppery color. At rest, this moth carries its wings close to its body rather than over its back. The Mediterranean flour moth holds its wings in the same position and is the same size, except the silvery-beige wings have scattered dark flecks. Both moths are poor fliers and fly erratically. The larvae look identical and are smooth, segmented, cream-colored caterpillars with brown heads.

Mediterranean flour moth
Mediterranean flour moth adult. Photo credit: Pest and Disease Image Library, Bugwood.org

The story begins when someone brings a food product into the house with Indianmeal moth or Mediterranean flour moth eggs or larvae inside. The larvae feed in the food product until they get as large as they will grow. As they travel, they leave a characteristic dusty silken thread behind them. Often, people mistake the threads for spider webs. They then leave the food product to pupate in another location like in a box of coffee filters, napkins or drinking straws. They will spin a silken cocoon around themselves and in about a week, they will emerge as an adult moth with wings.

Adults have only one purpose: date and mate. The eating days are over. The fertilized female looks for a food product to wiggle into. Eggs are laid on the food surface and mommy exits stage left. The eggs hatch and more larvae are feeding in the kitchen. Another generation is born.

The solution to the Moths of Misery is not found with pesticides. It has to do with checking all possible products and either disposing of them if they have “guests” or putting all good food into other containers. Because the moths can chew through plastic bags and various wraps and wiggle into aluminum foil, more durable containers are needed. Plastic or glass containers with screw tops or snap down lids work well. You can recycle food grade containers and re-label them. Plastic containers that originally held basmati or jasmine rice is an example. Food can be stored in the refrigerator or freezer. Larger amounts of dry dog food and bird seed can be stored in its original bag in a clean garage container with a lid in the garage until the moth problem has been solved.

Protect your assets from these hungry food wreckers. Your falafel mix will thank you.

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