Indian Meal Moths
What are Indian meal moths?
The Indian meal moth is found more than any other insect in stored food products in the United States. This insect got its name by being a pest of “Indian corn,” or maize. Like maize itself, the meal moth may have originated in South America. However, the meal moth is no longer exclusive to that continent and is a prevalent nuisance in the US.
How big are they?
The meal moth usually measures 3/8” long and has a wingspan of about 5/8.” They are easy to identify because of the rusty-red color covering the outer 2/3 of their body and gray coloring on the the inner 1/3 portion of their body.
Where do they lay their eggs?
A female meal moth will lay from 100 to 300 eggs during her lifetime. The eggs are laid either in groups or one at a time on food material and are difficult to see. For this reason, complete population control can be difficult to achieve at times.
Can you tell me a bit about their biology?
The feeding stage of the life cycle, the caterpillar, is dirty white to pink in color and measures about a ½”. It can be identified by two distinct black mandibles that are present on its head. The caterpillar will leave behind a thread wherever it goes and eventually spins a web when it is full-grown. Normal room temperature and readily available nutrition cause the caterpillar stage to last from 2 to 5 weeks. When it is much colder, this stage can last for up to two years. After spinning the cocoon, the adult emerges in 30 days. There are 4-6 generations per year.
How do I find them?
The Indian meal moth usually flies at night and can be observed hanging around lights or television sets. The adults will fly in a zigzagging pattern if disturbed during the day.
One way of knowing if you have meal moths is looking for food particles spun into their web.
What do they eat?
No food outside of a can or vacuum sealed container is safe from the meal moth. If you discover that you are infested, everything outside of these types of containers must be thrown out. Failure to do so will lead to re-infestation once more eggs hatch from the remaining food.