|Little brown moths, like this meal moth,|
Pyralis farinalis, can pose an identification
challenge to untrained PMPs.
But it's really not fair to the moths, or your customers, to give up so quickly on little brown moth identification--especially when the moth is an indoor pest. Household moths are pretty distinctive when examined carefully, and with a little practice identification decisions about indoor moths are not that difficult to sort out.
First a little background. Moths, along with butterflies, are insects in the Order Lepidoptera--one of the largest insect groups, with almost 175,000 known species. Perhaps the most distinctive lepidopterous feature is the membranous wing surface covered with flattened, modified hairs, called scales. Scales are what give each species of moth or butterfly their distinctive body and wing color pattern.
All Lepidoptera go through a complete metamorphosis as they develop. This metamorphosis starts out with the egg and larval, or caterpillar stage. After the caterpillar is fully developed there is a pupal stage, then the adult emerges. In moths, it is typically the caterpillar stage that causes the most damage to plants or to stored products; although in pest control the adult stage flying indoors can also be a problem.
|The most common indoor pantry|
pest is the Indian meal moth, shown
here resting in its characteristic
|Comparison of sizes and wing |
shapes of Indian meal moth (top),
Angoumois grain moth, and
clothes moth (bottom).
Clothes moths are the smallest of the moths likely to be found indoors (3/8-inch or 5-7 mm wingspan). They are covered with light brown to golden scales and have a tuft of hairs on the forehead. The hind wings lack a pointing finger shape. Clothes moths do not readily fly, and prefer to scuttle or run. For this reason, clothes moths can usually be ruled out as the culprit when a client reports seeing flying moths commonly indoors.
If in doubt as to the source of an indoor moth problem, pheromone lures can help. Pheromone lures contain copies of the sex pheromones that these moths use to locate mates. Pheromone lures can be placed throughout an account to help pinpoint moth hot spots. Some pheromone formulations for moths are even available as confusing agents to prevent males from finding female hosts (this approach is not effective for clothes moths, as explained in an interesting article just out in Fumigants and Pheromones newsletter). Pheromone traps are available for many species and Insects Limited is an excellent source for information on selection and technical aspects of pheromone use. Another commercial source for pheromones is Trécé Inc.
For anyone with deeper interests in stored product pest identification, including detailed keys to stored product pests, an excellent resource is the USDA Agriculture Handbook 655, Insect and Mite Pests in Food, now accessible online.
With all the great resources available there really is little reason to run from those Little Brown Moths.