Those White Worms Are Indian meal Moths
By Chris Williams on December 10, 2013.
Question
I recently called another pest control company because I saw several white worms crawling on my kitchen ceiling. The technician said we had a food moth infestation and that we needed to throw out a lot of our food and have the kitchen treated with insecticide. What do white worms have to do with food moths, or was he just trying to create business for his company?
Answer
Without being there, my guess is that the white worms you saw are the larval stage of the Indian meal moth, which is a common pest of stored foods in home kitchens. The worms are indeed moths…or soon will be. The larvae feed and grow in the food product and, when mature, they often leave the food and wander, looking for a protected place to pupate. When they emerge from the pupal cocoon, the worms have become adult moths.
Unfortunately the sight of larvae wandering up kitchen walls and across ceilings is often the customer’s first clue that there is an Indian meal moth infestation. While adult moths may be overlooked, multiple larvae wandering in a kitchen or storeroom are much more out of place.
Indian meal moth larvae are dirty white in color with a brown head and are about ½ inch long when fully grown. They look like caterpillars which, in fact, they are. The adult Indian meal moth is also about ½ inch long and light gray with a broad coppery band across its wings.
Check for Infested Foods
Indian meal moth larvae feed on a wide variety of foods including grain products like cornmeal, wheat flour, and cereals, but also nuts, chocolate, dried fruit, spices, bird seed, and dry pet food.
You may or may not need to throw out food as the technician stated. But you really do need to at least check any susceptible foods to see if they are infested. (See our blog, How to Check Food Products for Insects – Advice From the Pros.) The foods most likely to be infested are those that have been on the shelf the longest, or packages that have been damaged, overlooked, or stored in dark areas. Even unopened bags or packages can be infested. An overlooked Indian meal moth infestation can spread into other stored foods in your kitchen and pantry. It often is advisable to have a pest control company treat shelves and other areas to kill any new larvae that may hatch from eggs in cracks and crevices.