Description: The pantry moth or Indian meal moth (Plodia interpunctella) is considered to be the most troublesome of the moths infesting stored products in the United States. They attack all cereal products, whole grains, dried fruits, pet foods, bird seed, dried milk and nuts. Damage is caused by the larvae spinning silken threads as they feed and crawl, thus webbing the particles of food together. Small moths are often noticed flying in a zigzag fashion around pantries and other infested areas. On this page we show you how to get rid of pantry moths without using toxic sprays.
Adult moths (5/8 inch wingspan) are pale gray in color and are easily distinguished from other grain infesting moths by the reddish brown or coppery luster of their outer forewing. Fully grown larvae (1/2 inch) have brown heads and are dirty white in color, sometimes tinged with green, yellow or pink. They are extremely active.
Life Cycle: Adult females deposit up to 300 eggs on or near food materials. Within two weeks larvae hatch and begin actively feeding. As they move they spin silken threads throughout the infested foods, which may become matted with webbing. Larvae feed for approximately two weeks until fully grown and select a pupation site (cracks and crevices, pantry walls, ceilings) where they spin cocoons. Transformation to pupae occurs, and adults emerge in about 30 days. The entire life-cycle requires 4-6 weeks to complete and there may be five overlapping generations per year, depending on temperature.
Note: Pantry moths are most often introduced into the home in packaged goods and groceries. Here’s how to get rid of them naturally.
Control: Inspect foods for possible infestation before you purchase. Store susceptible foods in as dry a place or container as possible, for example, in pressure-sealed jars with rubber gaskets. Infested items can be thrown away or salvaged by freezing for 1 week. Clean up food spills promptly, paying close attention to cracks and crevices. The Pantry Pest Trap uses a powerful attractant to detect adult moths. Place the trap near the problem area, generally where dried foodstuffs are stored. Release trichogramma wasps to attack and destroy the eggs. These tiny beneficial insects are very effective because they prevent the pest from reaching the destructive larval stage. Bacillus thuringiensis, var. kurstaki or Monterey Garden Insect Spray (Spinosad) will kill the larva. Treat cracks and crevices with diatomaceous earth and/or botanical insecticides.
Tip: Vacuuming will remove many hiding insect pests. Empty the vacuum cleaner after use to prevent reinfestation.
Note: After all sources of infested food have been eliminated, it may take up to 3 weeks for moths to complete their life-stages.
Photo Credit: JC Schou