How to Identify Grain Moths

Uh-oh, there are moths in your rice and flour! Insects infestations are not only unsanitary--they're really gross, too. The usual suspects are one of three small, brown-ish moths that can be hard to tell apart. Here is a quick guide to their identification.

Things You'll Need

• Adult moths, larvae or eggs to examine and identify

Instructions

1. Look at the color of the wings. If they are two toned, pale tan closer to the head with darker brown stripes on the butt end, you are most likely dealing with Indian Meal Moths (Plodia interpunctella). Indian Meal Moths are 3/8 of an inch long, with prominent antennae. They have a weak, erratic flight, yet can be surprisingly hard to catch.

2. You can also identify Indian Meal Moths by their eggs and larvae. Indian Meal Moth eggs are white and very small, and the larvae are white with a brown head. The larvae produce sticky silk nests to protect themselves while feeding, and you may find these nests, which resemble a dense cobweb, in your rice, grains, flours or dry pasta.

3. Another possibility is Mediterranean Flour Moths (Ephestia kuehniella or Anagasta kuehniella), which are very closely related to Indian Meal Moths and eat many of the same foods. Mediterranean Flour Moths also have two-toned wings and their larvae produces silk webbing, although the Mediterranean Flour Moth's nest is more tunnel-like. Mediterranean Flour Moths are slightly larger than Indian Meal Moths, 1/2 inch long or longer.

4. If the wings are uniformly brown, you are probably dealing with the Angoumois Grain Moth (Sitotroga cerealell), which are approximately one third of an inch long. Angoumois Grain Moth larvae also have a different development process. Females lay their eggs on grain kernels, and when the eggs hatch, the larvae burrow into the grain kernel and feed on the inside of it. The larvae pupate inside the grain kernel, and then emerge as adults. If you find kernels of grain with small but obvious holes, you may have a Angoumois Grain Moth infestation. Angoumois Grain Moth feed on of many grains, but are most often found in corn, including popcorn.

Tips & Warnings

• Other insect pests that might be found in grain products are Red Flour Beetle, Sawtooth Grain Beetle, Dermestid Beetles, and Rice or Granary Weevils.