Moth Pests of Our Food

In many countries of the world insects and their larvae are part of a balanced diet. You cannot deny the nutritional value of a great big, juicy, squirming grub or caterpillar……as long as you can keep it down. I’m afraid that even I – the life-long bug enthusiast – would have a difficult time eating live insects, given that I have other options to choose from for food.

So, picture this. You stick your 75 cents into the vending machine for a candy bar (it USED to be a nickel), and choose your favorite – chocolate, caramel, and nuts – and peel back the wrapper and take a big bite. As you are chewing you notice a slightly different flavor this time, and you take a closer look at the candy bar and notice a little problem – there’s half of a worm sticking out of the area you just bit a chunk from. Yes, I said “half” of a worm, because you now are chewing on the High Protein version of this bar. This common event is probably caused by the presence of a moth larvae feeding on the nuts in the candy bar, often one called the Indian Meal Moth.

In many of the more undeveloped countries of the world a tremendous loss of the food grown for human consumption is attributed to the presence of bugs attacking that food first. It can be such a problem that just going ahead and accepting that you will eat a few weevils with your corn, or moth larvae with your bread, is a way of life. They generally are not going to hurt you, except mentally.

However, in the United States and most other “developed” countries eating insects is not an acceptable practice, and finding some tiny brown beetles crawling around on your kitchen counter becomes a cause for concern. Let’s take a look at some of the common Stored Food Insect Pests you will find in your home, and tell you how you can deal with this.

The Moths

There are around a dozen small moths that may be infesting food materials, but these can be divided into two groups, and it points out the need for proper identification. This is one reason you should consider contacting a licensed, trained pest control company for advice or help on eliminating the pest problem. These two groups are:

  • Moths that feed on sound, usable food products
  • Moths that feed on damp, deteriorating food that generally is not edible to people

Let’s tackle the second one first, the moths that feed on old, nasty foods. These are considered “secondary” pests, meaning it is the deteriorating condition of the food that attracted them. One common moth we find in this situation is called, simply, The Meal Moth, and if you find a number of these in your home it is an indication that somewhere, somehow, you have a forgotten package of food that has been there a long time, possibly in a damp situation, and it has attracted these moths. A few examples I have seen include bags of nuts stored in the garage for several years, piles of old feed in a chicken enclosure, and most common of all, dog food stashed inside wall voids by rats.

If you’ve been noticing the dry dog food nuggets disappearing faster than you think the dog should be eating it, check to see if you have a rat problem. They will steal the pet food and “cache” it in the walls. Squirrels also like to do this, removing dog food from bags and stashing in their own, personal supply places for future use. On one occasion over 30 pounds of dog food were found stashed in a squirrel’s private place.

Obviously, the control for these moths is to eliminate the food source, and if it is within the walls of your home this can be a huge undertaking, but one that must be done. Step one, though, is to correctly identify the moths, so you know for certain what you are dealing with.

The more common problem, though, is moths that get into the various packages of relatively sound foods that you have in your cupboards, although it still is normally those packages that have sat too long in the cupboards, giving the bugs a chance to get their populations rolling along. There are several common species of moths you likely can encounter, but since they all may infest the same kinds of foods we will concentrate on the worst and most common of them – The Indian Meal Moth. This is a very distinctive moth, with the wings held back over the body when it is resting on a surface. The outer half of the forewings is a coppery-red color, while the half closer to the body is creamy-white. The adult moth generally avoids lights, so you won’t find it at the porch light or banging into your reading lamp.

Some of the other moths are those such as The Mediterranean Flour Moth, The Tobacco Moth, and The Almond Moth, and these names are given due to the moths’ propensity for feeding on certain food materials, but don’t let it fool you – they will go after just about everything else too. In all cases it is the LARVA stage that does all the damage. In fact, most of the adult moths don’t feed at all, and die soon after laying their eggs. But, the adults had to come from larvae, so their presence sitting or flying in your home can mean you have some infested food somewhere.

The laundry list of possible foods that these moths can attack would go like this, but it includes just about ANYTHING made from plant material – grains, nuts, fruit, etc.:

  • Flour and other baking meals – brownie mix, cornbread mix, cake mix, powdered milk, etc.
  • Nuts – whether in the shell or out of the shell, within packages, within candy bars or cookies
  • Grain products – pet food, bread, crackers, chips, bird seed
  • Spices – peppers, paprika, etc.
  • Dried flowers – bouquet arrangements, as well as other decorative arrangements of wheat stalks, flowers, acorns, nuts, pine cones, dried corn, etc.

The last two Indian Meal Moth infestations I inspected for were traced to arrangements of dried flowers, one in a home and one in a nice clothing shop. The larva of this moth is distinctive by its lack of any spots on its body. It is smooth, white, pinkish, cream colored, or even with a greenish tint, and it has the annoying habit of leaving the food it is infesting and wandering off to find a different place to make its cocoon. People commonly find the cocoons or larvae several rooms away from where they actually were infesting food. One time it was a bag of nuts in the closet in a child’s room (for feeding local squirrels) that was infested, but the larvae and adults were in the living room.

The Beetles

Just as with the moths, the beetles that invade our food can be grouped into food preferences, but here it gets a little tricky. There are DOZENS of different kinds of tiny beetles that invade our food, and this makes it even more important, perhaps, to consult with a trained professional, who understands how to identify the bugs and knows their habits. There are several tiny weevils that almost always are found in WHOLE seeds of some sort – they don’t like processed foods. In your home this could be bird seed, a bag of beans or rice, the Christmas wreath with its acorns, chestnuts, and pine cones, or a decorative arrangement of Indian Corn put out for Thanksgiving.

There also are a number of extremely tiny beetles that generally are referred to as “fungus” beetles, and for good reason. They prefer damp, moldy foods, and it is the tiny bits of mold or fungus that their larvae seek for nutrition. Obviously, these foods would no longer be very tasty to you and your family, and finding them and disposing of them is the answer, although sometimes “finding” them can be a real test of your ability to play Sherlock Holmes.

However, of all the beetle pests the most common one in homes is a small brown kind called The Drugstore Beetle, and like the Indian Meal Moth it is capable of feeding on almost everything you store in your kitchen. Dry dog food nuggets are an extremely common source, as are old rolls of bread or croutons. But, whenever I am faced with a Drugstore Beetle problem the very first place I look is the spice rack. These beetles will infest just about every kind of spice you can imagine – paprika, cloves, cinnamon, all kinds of peppers including jalapeno peppers. They can be powdered, ground, or whole – doesn’t matter. They can be in boxes or plastic jars – doesn’t matter, because the beetles will chew right through these soft outer packages.

The Control

Step #1
Find the source of the problem. If you find a package of infested foods don’t stop looking. I once found Indian Meal Moths in 12 different boxes of foods in a cupboard in someone’s home. They move from package to package if things sit there long enough.

Step #2
Throw it away. Even though most insect larvae are not harmful to eat, unless you are the adventurous sort it probably is easiest to just bag up the package and toss it in the garbage.

Step #3
Clean up. Very thoroughly vacuum all the cupboards to remove food scraps that are laying around and attracting bugs. I took a look in the cupboard at my house, where we set our toaster, and found a pile of bread crumbs under the toaster as well as a huge accumulation of crumbs in the bottom tray of the toaster itself. Cleaning also removes any wandering beetles, moth larvae, or possibly moth pupae that are outside the infested packages.

Step #4
Sometimes, a follow-up application of insecticide will be very useful, but I’d suggest you allow the professionals to do this. Licensed pest management companies use products that you may not be able to buy on retail shelves, and these products are more appropriate for use around your food. They have no odor, so vapors, and are very low in toxicity to people and pets. Their benefit is to intercept any final insect adults or larvae that have escaped your search and destroy cleaning mission, and kill them before they have the opportunity to start a new invasion.

Even if you contract with a licensed company for the control of food pests in your home, they probably will ask you to take the first three steps before they get there, and rather than pay them by the hour for looking through the packages for you it probably is best to do it yourself. For preventing future problems with food invading bugs, keep these steps in mind:

  • Store susceptible foods in sealed, impermeable containers – thin plastic can be chewed through by the beetles
  • Store foods in dry locations, and the cooler the better
  • Stock turnover – use things up – don’t let packages sit for months or years without using them
  • Inspect – on a regular basis remove the boxes, or bags of noodles, and check them for signs of insects. This helps discover a problem in the early stages.
  • Cleaning – don’t allow accumulations of spilled foods in cupboards, under the refrigerator, in the garage, or anywhere else you store human or pet foods
  • Check when you buy foods – grocery stores are not immune, and commonly have infested packages too that you can bring home. Most susceptible may be “health” foods that have avoided insect control processes in manufacturing, or “bulk” foods that are not routinely emptied

So, let’s get out there and eat healthy.