Down the Garden Path

Richard Hentschel, Extension Educator

Now that the Holidays and Super bowl Sunday are over and pretty much our lives have returned to a more normal routine, there may be some insects beginning to show up in the pantry or kitchen. Leftover baking goods are usually the culprit and enough time has passed that we should be on the lookout.

There may be a variety of insects that may show up, but in general, we lump them together and call them pantry pests. In nearly all cases, the adult flies and the larvae are worm like. The two more common ones are the Indian Meal Moth and the two versions of a Flour Grain Beetles. While they have slightly different life cycles, generally eggs hatch in any kind a product that contains flour where the larvae stage feeds until it is time to transform into an adult.

In the case of the Indian Meal Moth, the larvae will crawl away from the product, find a crack or crevice in the pantry and pupate where later, it emerges an adult moth. The flour beetles typically pupate right in the product that they have been feeding on. The meal moth will be attracted to a light source, so you will see them flying about the kitchen windows and light fixtures. This may be your first clue that there is a contaminated product in the pantry.

Once they are discovered, a very through sorting and cleaning of the pantry is in order. Leftover baking goods are the most common culprit in the cupboard. Leftover flower from baking is a common source. White flower will take on a dull grey look. As the meal moth feeds, they leave behind webbing that can be seen clinging to product and the product container. Flour beetles can be found in various stages of development from larvae through adult beetles, which are very small. All contaminated products should be disposed of outside of the home until garbage pickup. Other products that appear ok should be considered suspect, as there may be eggs that have yet to thatch. Products like oatmeal, cake and pancake mixes, pasta products and any kind of grain cereals should be on your list to inspect. A couple of other products to check are the dried dog and cat foods and wild birdseed supplies.

Any remaining products should be put into tight sealing plastic containers to keep them separated in case you find additional insects, you will not have to inspect every product you have again. The same should be done for any brand new products from the store until you are sure the outbreak has been contained. By throwing out the contaminated products, you will have handled the flour beetles. Indian Meal Moths take a little more work. A thorough cleaning of the pantry shelves must be done as larvae will have found a place to pupate into an adult moth. If the shelves are removable, do so to vacuum. The larvae will also crawl into the corners of the pantry so be sure to vacuum all the corners and the ceiling corners too. Holds off on putting new shelve paper down until you know that the insects are gone for good.

About the author: Richard Hentschel’s expertise extends across several subject areas with specialties in lawn care, fruit tree production, woody ornamentals, and home and community gardening. During his 45-year career in horticulture and agriculture, Hentschel became a well-known and respected expert for commercial and homeowner audiences, industry organizations, and media. He retired from University of Illinois Extension in April 2022 with nearly 30 years of service as a Horticulture Specialist and Educator in northern Illinois.