May 27, 2022

They’re back: Taking care of winter pantry pests

While pantry pests generally show up in February and March, University of Illinois Extension already is getting emails and calls. If I am going to guess, we have been at home, baking and cooking more in 2021. And the cycle started earlier.

Identification is a good place to start. From there, understanding the pest life cycle guides us through the removal process. The most common pantry pests are a kind of moth and a couple kinds of grain beetles. One is easier to spot than the others.

The Indian meal moth adult will be seen flying around in the pantry or cupboard and circling light fixtures at night and windows during the day, while the beetles do not. The moth often is the one we see first, as the beetles do not leave their food source. Both the moth and the beetles have a complete life cycle – adult, egg, larva (worm), and pupa (cocoon). This plays into your removal and management of these pantry pests. Typically, these pantry pests establish themselves when unused grain products linger in the pantry. The flour used for baking cookies and pies after the holiday season makes its way to the rear of the shelf and there it stays.

What to do

Once found, the first step is a very thorough cleaning of the pantry to remove any infected products. This includes any foodstuffs containing flour, regardless of whether it’s highly processed or not. Examples include cake, cupcake, corn bread and pancake mixes; crackers; pasta products; oatmeal; and any breakfast cereals – anything that contains flour as an ingredient. Flour no longer will have that bright white color, being a gray with webbing in the bag or box. All those go in the garbage. Those Indian meal moth larvae crawl away and pupate away from what they eat. The next step is cleaning the pantry shelves, cracks and crevices including using the nozzle on the vacuum to get into those tight spots. If the shelves are movable, take them out to expose webbed cocoons. Do not forget to vacuum the ceiling and wall corners. Wait to put fresh shelf paper down until you know the pests are completely gone.

After you have cleaned

Those foodstuffs that are left need be placed in tightly sealed containers in case they were contaminated with eggs that had not hatched before your inspection. If later you find a product with a problem, you are only throwing out that individual product and do not have to inspect the entire pantry again. You can place unused flour in the refrigerator or freezer until used up.

Be vigilant over the next four to six weeks looking for the flying Indian meal moth and their larvae along with the small grain beetles in the remaining products. It is not uncommon to see the moths, but without being able to find a food source to lay their eggs, you will have broken the life cycle. In the future, buy products containing flour in a quantity that will be used up in a month, not long enough for another outbreak to occur.

• Richard Hentschel is a Horticulture Extension educator with University of Illinois Extension, serving DuPage, Kane and Kendall counties. This column originates on his blog at To get more tips from Hentschel, watch his “This Week in the Garden” videos on Facebook and YouTube.