What Are Caterpillars Doing in My Kitchen?
By Chris Williams on October 10, 2016.
I keep finding these white worms crawling on my kitchen walls. I thought they were fly maggots but they look more like little caterpillars, about a half inch long. I can’t imagine what they’re doing in the kitchen. Could they be coming in from outside? P. D., Sandown, NH
Whether or not they could be coming in from outside depends on how many you’re seeing at one time and whether you have been seeing them over an extended period of time. If this is an ongoing event, I think you might be seeing the larval stage of a food moth, probably the Indian meal moth.
Indian Meal Moths Are Pests of Stored Foods
Saying that they “look like caterpillars” is a clue. Another clue is that they are “crawling on walls.” Fly maggots don’t have a caterpillar shape and they also don’t have legs…so, no wall climbing for them. Actually, your complaint is a fairly common one. Indian meal moths might be our most common stored food pests. One reason that Indian meal moths are such serious pests is that the larvae will feed on almost anything from cornmeal, flour, or cereals to nuts, fish food, spices, chocolate, and much more.
Indian meal moths can develop in bulk foods or in packaged or bagged foods stored in your cabinets, or even in bags of dry pet food or birdseed in the garage. In some cases, the moth larvae feed on food that mice have hoarded in wall voids and other secret places (see The Indian Meal Moth – Mouse Connection Explained). You may have seen the adult moths without paying much attention. They’re about 3/8-inch long with gray wings ending in a wide coppery band. They hide during the day but at night will fly in a zig-zag manner and are attracted to lights.
Indian Meal Moth Larvae Have a Need to Wander
Indian meal moth larvae have the habit of leaving their food source once they’re mature. At this point, the larvae are about ½-inch long and dirty white or pale pinkish in color. They are almost hairless with 3 pairs of short legs at the front end of the body and a brown head. The larvae are looking for a place to spin a pupation cocoon before turning into adult moths (see Meal Moths Leave Cocoons Behind). They often crawl upward, ending up in a wall/ceiling corner or the upper inside corner of a cabinet. They also pupate in seams or flaps of food boxes or bags and other protected sites.
Success Hinges on Finding the Infested Foods
The hard part is finding the source of the infestation and, since these moths feed on so many foods, there’s often more than one food infested. It means you really have to go through most everything in your cabinets and pantry, emptying out the food product and looking for larvae, shed skins, or silken webbing. Adult moths are usually found in the food only when they are laying eggs (see How to Check Food Products for Insects – Advice From the Pros). Keep in mind that infestations are most often found in those food packages that are the oldest, that are past their “Use By” date, are damaged, or are damp and moldy.
Eliminating a food moth infestation can be time-consuming and frustrating because just when you think you’re done with them, eggs might hatch in another food product and a few weeks later, you’re seeing larvae or moths again. Give Colonial Pest a call. Our technician can confirm that you have an Indian meal moth problem and can inspect and treat appropriate sites. When the job is done, we can install a pheromone trap that will give you an early warning if food moths have returned. If they do, our work is guaranteed!