How do we get rid of grain moths in our house?

Asked August 7, 2014, 3:24 PM EDT

Our house is infected with grain moths. We have taken several measures to try to eliminate them. We have used traps with pheromone (sex lure) and cleaned everything and sprayed the cupboard with home defense. Still, they are everywhere, probably including in the attic, as they appear in the hall ceiling near the attic door. We have been freezing grains and seeds for three weeks. However we don't know whether the eggs and larvae can be frozen to death or have a defense that allows them to live after freezing. Also, we heard that heat (130 degrees) has been used to eliminate bedbugs, but we don't know whether that works for grain moths. We are looking for a total-house solution, such as draining the pipes and leaving the house for three weeks in January, typically a cold month in Michigan. Any suggestions?

Branch County Michigan

1 Response

Grain moths are a food problem, not a whole-house problem. If instead the pests are Indian meal moths or Mediterranean flour moths, none of the measures you describe are necessary to eliminate them. Assuming that the pests have been correctly identified and are grain moths, use the following method to eliminate them from your house.

Check all the foods that these pests get into: grain-based foods, nuts, potato flakes, rice, and, possibly, chocolate and spices. Also check dry dog food and cat food and birdseed. Remove from the home products that show evidence of the pests. If a product shows no evidence of webbing, put it into a sealed, airtight container or the refrigerator or freezer. Put birdseed or pet food in a clean garbage can in the garage, in its original bag. Use a tight lid and a bungee strap to cover the garbage can if other pests are in the garage.

The key is to containerize, refrigerate, or remove from the house any source that the moths are using. If there is nothing to eat, the life cycle ends. Mommy can lay all the eggs she wants, but if the kiddies cannot eat, they die. It might take several months for adults to stop appearing. Many people permanently keep food in food-grade containers. If insects are in a food item, they cannot get out of such a container. Conversely, if the food product has no pests, none can get in.