Flour and Pantry Moths

Generally, pantry moths are either the Indian Meal Moth (Plodia interpunctella) or the Mediterranean Flour Moth (Plodia interpunctella) . The larvae, commonly called waxworms, eat flour, whole grains, crackers, peas, beans, nuts, dried fruit, spices and even dry pet food. The Mediterranean flour moth is a bit smaller (about ½″), and is usually pale gray with two black lines on its forewings. The Indian meal moth, about ¾″ long, also has pale gray wings though has a reddish-brown coloring on its outer forewings.

Life Cycle of the Pantry Moth

Moths follow the life cycle: egg, larva, pupa and adult. The life cycle may be completed in as little as 30 days or as long as 300 days, depending on food availability and temperature. The warmer the temperature, the faster the cycle completes. The average is 4-7 weeks. Usually, the first noticed is the adult, which will only live 1 or 2 weeks without feeding. During this time, the female may lay up to 650 eggs at a time directly on the food source that will be used by the larvae. Eggs are a whitish-gray color and are quite small; they will hatch in 2-7 days. Pantry moth larvae will take 14-40 days to fully develop, devouring whatever the food source is. Usually the first several inches of the infested food are totally ruined. Indian meal moth larvae will go somewhere other than the food source to pupate, typically seeking the crevices of pantry shelves or the seams of doorways. In most cases, the Mediterranean flour moth larvae will spin the cocoon directly in the food source, which is why infected foods may have a matted web. Moth pupae are no more than ⅓ ″ long and may be as small as ¼″. The pantry moth pupa stage will last 4-30 days.

Pantry Moth Prevention: take their food away!

Inspect all foods before you bring them into your pantries. If there are any signs of moths, bag and discard the package, or return it and warn the store where you purchased it. Look for telltale signs of moths: small holes in the packaging and webbing in the tighter areas of the package.
Store all foods in tightly sealed containers to prevent moths from spreading, just in case something is contaminated.
Keep areas that may collect crumbs, like toasters, clean.

Pantry Moth Control: take their food away and catch adult males!

Once you spot adult moths, go through your pantry and discard all infected foods.
Seal up all other foods to keep moths from having a place to deposit their eggs.
Put out Pantry Moth traps to capture the adult male moths. This will keep the females from depositing fertilized eggs.
If you have a larger quantity of grain or rice to store, you may wish to add food-grade diatomaceous earth to the top. This will kill the larvae or any adult moths that come in contact with it. Do not store in bags; store in sealed containers.