Leftover baking goods are usually the culprit, especially any flour or flour-based cooking and baking product. This is a bit more troublesome for homes where baking starts before the holidays and quits soon afterwards as our normal routine returns.
The more common pantry pests are the Indian Meal Moth and the two versions of Flour Grain Beetle. We receive more calls about the Indian Meal Moth than the grain beetle. The meal moth will be attracted to windows and lights, so it is a lot more obvious if you have a problem. While the pests have slightly different life cycles, generally eggs hatch in any kind a product that contains flour. The larvae stage feeds until it is time to transform into an adult.
The key to preventing these pantry pests is not to have any leftover flour that is going to be accidentally worked to the back of the shelf in the cupboard or pantry. It is better to use the flour up in cooking and baking than attempt to store it. If the flour is to be kept, store it in a very tight-sealing plastic container, keep it in the refrigerator, or even better, the freezer. If later you do find some of that stored flour to be contaminated in your pantry, then it is a matter of disposing of just that one container. Storing flour in the refrigerator dramatically slows the potential of finding contamination and if left in a freezer, to zero or below, there will no chance of anything going wrong.
Flour products are not the only way pantry pests can make it into your home. Did you buy a dried flower arrangement or make one that contained flower seed heads from your own flower beds? Other potential sources include any of our dry pet foods that contain flour as an ingredient. Buy just enough to last a month to prevent the time needed for any pantry pests to show up. One of our favorite winter past times is to feed and watch the birds. If you do buy bird seed in large amounts, be sure to store it in an unheated area like the garage and in a tight-sealing container, as you would the flour in the pantry. The same goes for the food for our furry four-legged pets like gerbils, mice, rabbits, and the birds too.
So go ahead, bake those dozens of cookies for the cookie exchange, just remember, store the leftover flour properly.
Richard Hentschel is a Horticulture Extension Educator with University of Illinois Extension, serving DuPage, Kane and Kendall counties. Stay tuned to more garden and yard updates with the Green Side Up podcast at go.illinois.edu/greensideup.