Indian Meal Moth

The Indian meal moth is a common insect found infesting food products. Almost any coarse grains (oatmeal, grits, etc), nuts, seeds, dried pet foods, candy bars, spices, cocoa, dried fruits or vegetables (e.g., chilis) are suitable materials for Indian meal moth development. However, flour is rarely infested by Indian-meal moth.

The adult stage of the Indian meal moth is about one-half inch in length, generally gray in color with the bronze wing tips. The moth is the most common small moth found flying in Colorado homes. Feeding damage is done by the larvae (‘worms’) which are usually light colored (pale yellow to pink) with a dark head. When feeding the larvae produce webbing that is mixed with food particles and droppings.

An Indian Meal Moth Larvae An Indian Meal Moth Larvae

Most of Indian Meal Moth household infestations originate from the inadvertent purchase of infested products. During warm months, localized movements of the moths may also occur outdoors, resulting in household infestations in this manner. Because of the broad distribution of the insect, it is rarely possible to definitely establish the original source of a meal moth infestation unless detected at purchase.

Eggs are laid by the adult moths near suitable food, such as along cracks or folds of packages. The newly hatched larvae are very small and are capable of penetrating into loosely closed packaging. Upon reaching a suitable food, they begin to feed. Development can be rapid under favorable conditions and the larvae ultimately reach a length of about one-half inch.

Pupation then occurs after which the adult moths emerge. Adult female moths are then capable of laying 200-400 eggs during their lifetime of several weeks. Complete development of the Indian meal moth varies due to temperature and food but typically requires at least a month to complete.