Indian Meal Moth
Up to 0.625 inch in length.
The front wing of an Indian meal moth is a reddish copper colour on the outer two-thirds.
A female Indian meal moth lays 100-400 eggs on food materials during her life span. The larvae grow to 0.75 inch in length and have greenish tinge in appearance. They construct webbing cases or tunnels throughout infested food, usually rendering it unusable. At maturity, the larvae crawl out of infested foods and wander on walls, floors, etc. in search of a site to pupate. The fine silk cocoon, which houses a brownish pupa, is often located in corners, in crevices and behind items against or hanging on walls. If the larvae are unable to find their way out of the food package, they will pupate within that container. The life cycle lasts from 25 to 135 days depending on factors such as temperature and food quality. Adult Indian meal moths tend to avoid light and rest quietly on walls and ceilings. This moth is a weak flier and becomes active after dusk or in low light conditions.
The Indian meal moth is the most common moth of stored dried foods and is the pest moth most often seen in homes. This moth usually enters homes in boxes or bags of infested foods. It appears in all points of the food processing chain from the grain silo to the food plant to the warehouse to the supermarket shelf and ultimately into restaurants, homes and other end-users of food products. This moth infests a wide variety of food items, including flour, cereal, nuts, grains, chocolate, birdseed and dried pet foods. It is also present outdoors, occurring naturally and has been known to invade buildings from outside
Tips for Control
The control of any stored product pest involves many steps, primary of which is discovery of infested food items or other sources of infestation (e.g., food spillage accumulation). All dried food products need to be inspected for signs of infestation, including cereals, packaged dried foods (e.g., food bars and chocolate), nuts and pet foods. Indian meal moths have also been found infesting spices, potpourri and decorations made of vegetative materials. Keep in mind that infested items may not always be stored in the kitchen. Spices, potpourri and decorations made of vegetative products may be stored in any room of a house. A common source is bags of birdseed stored in the garage or basement. Infestations have also been traced to caches of nuts and seeds accumulated by squirrels or rodents within attics, walls and chimneys.
Also consider the following to prevent an infestation:
Discard infested foods in outdoor trash. Infested decorations (flowers, wreaths, etc.) should also be discarded.
Freeze suspect foods at zero degrees Fahrenheit for six days.
Clean cabinets and shelves where infested foods are stored by vacuuming and by using soap and water.
Store all dried food goods, including dried pet foods and birdseed, in a glass or plastic container with a tight lid. If Indian meal moths are in that food product, then the infestation will be contained and not spread to other foods.
Consider storing cereals and similar foods in the refrigerator to limit stored product pest problems.
Consume older food products prior to newer purchases of the same food. Products purchased in larger quantities (e.g., from a wholesale food warehouse) are more likely to become an infestation source if these are stored for long periods of time – especially if they are not stored in containers with tight-fitting lids.
A pest management professional can be helpful in finding difficult infestation sources.