Meal moths in the home are annoying by their very presence, and their larvae or caterpillars can damage or destroy many foodstuffs. There are four or five common meal moth species in the Delaware Valley, but we have the most problems with just one, the Indian Meal Moth, because it outnumbers all the other by far.

Scientists call the Indian Meal Moth plodia interpunctella – its common name derives from the frequency with which it is found infesting corn meal (often called Indian Meal). Indian Meal Moths have varied appetites and can be found in many kinds of grain and grain products: seeds, nuts, crackers, fresh and dried fruits, pet foods, candies, spices and many other commodities.

Infestations start when the ubiquitous adult moth lays eggs – possibly hundreds – on or on an acceptable food supply. These eggs may be, and often are, already in the packaged material brought into the house from the market. The tiny caterpillars hatch from these eggs, construct a sort of loose cocoon or shelter from the silk they produce, mixed with bits and particles of the material they are feeding in. This provides a kind of camouflage. They feed from within these cocoons and eventually the infested material becomes covered and matted with the silken strands. The larvae grow as they feed and eventually reach a length of twelve to fifteen mm (1/2 in.). When the larvae are fed up (literally) they often crawl away from their food source and seek a more sheltered place to spin a cocoon and “pupate” or change into the adult form of the moth. While the larvae may develop for many months the adults are short-lived. They die in anywhere from several days to two weeks, but before they do they will mate, lay eggs, and prolong the infestation.

Control of meal moths first involves locating and removing or destroying the source of the infestation. If a careful search of the kitchen and pantry turns up nothing, consider more unusual sources. These may be decorative items made of dried macaroni or beans, bean bag toys and furniture or flour spilled behind the stove. Houses that have had mice or rates often have secret “caches” of food that the rodents stole and hid inside walls, Infestations such as these can be very difficult to locate and control. One more not about rodents – commercial poison bait preparations for mice and rate are perfectly suited for the development of these moths.

Infestations often arise from a forgotten tray of mouse poison hidden in a closet or behind a bath tub. Once the infestation material is removed, chemical control may or may not be called for. Check with you Mid-Atlantic IPM Consultant for advice in particular situations.

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