A reader wrote to use recently with a straightforward question: “How do you get rid of meal worms in a pantry?” She is further wondering if you need an exterminator to get rid of mealworms (or “meal worms,” as the reader put it, which is correct as well), or if she can handle getting rid of the worms herself. Presumably, the reader is dealing with mealworms in her pantry, or else she is just curious about mealworm infestations in pantries. In any case, we do have some helpful information for getting rid of mealworms, which in normal cases should not require an exterminator.

(Photo Credit: MarioM / CC-BY-SA-3.0)

Mealworms are the larval form of the mealworm beetle, or Tenebrio molitor, and are one of the more than 20,000 species of darkling beetles in the world. In addition to being a common pest, mealworms are frequently used as pet food. Small animals like birds and reptiles love them, as do fish. (They are also consumed by humans in some parts of the world, which reminds us of a question a reader once asked about eating phoenix worms. Answering this question gave us an opportunity to touch on the interesting topic of entomophagy.) Although they eat many different things, mealworms have a penchant for oats and grains, which explains why they are often found in pantries, generally in foods like cereal and crackers.

Apart from ruining your food, mealworms also breed quickly and prolifically, which is why they can be a major nuisance. Adult female beetles can lay around 500 eggs, and in about one to three weeks a sizable portion of these eggs will hatch, thereby introducing a new army of larvae, or mealworms. As the mealworms mature through various instars (i.e., developmental stages en route to becoming a pupa), they consume lots of food, and it is during this period of eating and maturation that people generally discover their mealworm problem.

Because insect populations can quickly get out of hand because of their prodigious fertility, it is important to eliminate mealworms as soon as you find them. (And you are not just looking to eliminate mealworms, but also the adult beetles and the eggs they produce – all generations must be wiped out, or else a new round of mealworms will emerge.) Getting rid of mealworms is really a matter of cleaning. This doesn’t make the process easy, but it is straightforward. You must first throw away any food in your pantry that is or might be contaminated with mealworms. Unfortunately, this can often mean throwing away quite a bit of food, but in the long run this is the smartest thing to do. Obviously, food in which you can see mealworms is contaminated, but nearby food might be as well. If you have a row of cardboard cereal boxes, for instance, and you find mealworms in one, it is probably best to throw them all away, alas. The same goes for other similar products that are not in sealed containers and are in the same area.

After contaminated food (or food that is believed to be contaminated) is disposed of, you should thoroughly clean your pantry. You definitely shouldn’t use any heavy chemicals or insecticides (you are cleaning a place where you store food, after all), but some sort of disinfectant won’t hurt. You’ll want to be especially alert of any spilled drinks or food crumbs that are laying around, as these are an easy-to-access food source for mealworms. You’ll also want to try your best to clean the nooks and crannies in your pantry in case eggs where laid in these areas.

As long as the mealworm problem wasn’t totally out of hand, this cleaning process should get rid of the mealworms, which means you won’t have to call an exterminator. However, you’ll want to be vigilant about the problem and make sure the mealworms aren’t returning. To that end, you should make sure grain and oat products are sealed as well as possible (an investment in some plastic containers might be in order), and you’ll also want to make sure your pantry stays clean and dry. Essentially anyone can get mealworms, but if you address the problem promptly and aggressively, they shouldn’t be a problem for long.