If you've ever opened a box of food or bag of pet food and seen little white worms with black heads, had moths fly out of the package, or wondered why the food looks like it has webs ... you may have Indianmeal moths in your food!
Indianmeal moths are one of the most common and most troublesome of all food-infesting pests across much of the U.S.
These tiny insects are sometimes thought to be clothes moths, because, often, the first thing you see that makes you suspect you have pests is small moths zigzagging around the kitchen, or flying toward lights, such as lamps and TV screens. But it's not these moths that cause the greatest problem, it's the larvae, or worms, that feed on and build webs across pantry foods. The moths, of the Indianmeal species, are more of an annoyance – and they are an indication that you have a problem!
Indianmeal Moth Identification
The adult Indianmeal moth:
- is about 3/8-inch long with a wingspan of 1/2 to 3/4 inch.
- has reddish-brown wing tips, the wings are light gray or yellow near the head.
- has a reddish-brown head and upper body with grayish legs.
- flies primarily at dusk and is attracted to light.
The Indianmeal moth larval worm:
- is about 2/3 inch when fully grown.
- is cream or dirty white colored with yellowish green or pink shading.
- has a dark brown head.
- are sometimes called simply "white worms with black heads."
Indianmeal Moth Behavior and Damage
Although the Indianmeal moth may fly in from the outdoors during warm weather, it is usually brought into the home in packaged foods, pet foods. The moth can reproduce quickly to contaminate and damage food.
Adult Indianmeal moths do not feed, so they don't usually live for more than about a week. Their main purpose is to mate, then for the female to lay her eggs. A single female can lay up to 300 eggs during her short lifespan. These will be laid singly or in clusters on food or in cracks and crevices in food areas.
When the larvae hatch from the eggs, they will begin to feed on the food on or near which the eggs were laid. As they feed, they produce a silken webbing that covers and sticks to the food. This is another one of the most common signs that you have an Indianmeal moth infestation.
Foods Indianmeal Moths Infest
Some of the most common foods that attract Indianmeal moth larvae to feed and infest are:
- coarse grains, such as cornmeal, oatmeal, grits.
- breakfast cereals that come in bags or boxes.
- spices, dried soups, and dried pastas.
- dried herbs, fruits, and vegetables.
- nuts, crackers, and candies.
- baking products, such as cornmeal, flour, and powdered milk.
- pet foods, such as dry dog and cat foods, flaked fish food, and bird seed.
Indianmeal moths will even feed on non-food items that are all-natural, such as ornamental and craft items made from natural materials, dried flowers, seeds, etc.
When they infest large packages, the larval worms usually stay and feed on or near the surface of the food, but they may be anywhere in a food. This is especially in smaller packages, where the larvae will burrow down into the food to continue to feed. The tiny Indianmeal moth worm can get into even sealed products because it can chew through plastic bags and thin boxes to get to the food.
Because the adult female may lay her eggs in cracks near foods, the hatching larva will also be found there as they begin to crawl out in search of food. When the larvae are ready to pupate, they will also often leave the food to seek a crack or confined space to do so.
Although Indianmeal moths and their larvae can be a significant problem, they can be controlled. To find out how to control them, read Part 2, Controlling and Eliminating the Indianmeal Moth