University of Illinois Extension

Pantry Insects and the Holidays

Although the holidays are some weeks off, now is not too early to start taking precautions against pantry insects, said a University of Illinois Extension horticulture educator.

“Many people think the pantry insects such as Indian meal moths are coming into their homes because their food is contaminated,” said James Schuster. “This happens occasionally but it is the least-common way these insects get into the home.

More often, the insects come in on dried cat and dog food.

James Schuster

“More often, the insects come in on dried cat and dog food. However, most often the different kinds of insects that are considered ‘pantry insects’ invade our homes in bird food.”

The insects, Schuster explained, may be in the bird food as eggs, larvae, pupa or even adults. The larvae feed in the food. Eggs and pupa can be in or on the packaging material. Once the pantry insects are in the warm environment of the home, the life cycles often start to overlap.

“Depending on how soon in the fall you brought in the birdseed and large quantities of dried dog and cat food, emerging adults can appear sometime from just before Thanksgiving to after New Years,” he said. “They will continue to emerge through the rest of the year unless they are controlled. Each successive generation is larger than its predecessor.”

Although the birds, cats, and dogs don’t mind the insects, most people don’t want the pests crawling and flying around the house. To reduce this possibility, Schuster suggested that the bird seed/pet food be frozen quickly--in less than 24 hours.

“If the bird seed/pet food does not freeze within 24 hours, the insects will start making alcohol in their ‘blood’ and will survive the freezing process,” he said. “If the seed/food was frozen slowly, then the seed/food needs to be put into an airtight container and kept at room temperatures so that the insects loose their alcohol. This takes about two or more weeks.

“Once the insects are alcohol free, re-freeze the bird seed/pet food quickly. No matter where you store the bird seed/pet food, keep it in an airtight container.”

If it is stored outside, consideration should be given to using an airtight container that is in turn kept in a steel garbage can that has a chained lid. This keeps raccoons and squirrels from eating through the airtight container and getting to the bird seed/pet food.

“If insects are already flying and crawling, sanitation is the only recommended control,” Schuster noted. “Contaminated human food is discarded. All non-contaminated human food and any dried pet food should be frozen quickly and stored in airtight containers.”

The food should be kept stored in airtight containers for the next six months and opened only long enough to remove the necessary food.

“All cupboards, cracks and crevices should be thoroughly washed with a strong soap and water solution,” Schuster said. “Rinse clean and dry. Do not use an insecticide to control these insects in the home.”