INDIAN MEAL MOTH
(Lepidoptera: Pyralidae: Phycitinae)

The Indian meal moth, Plodia interpunctella, is a very common food-infesting pest. It is a general feeder on grain and grain products, dried fruits, seeds, nuts, powdered milk, chocolate, candies, and some spices. Occasionally pet food and birdseed for outdoor feeders become infested and cause problems when stored indoors.

© http://www.uark.edu/depts/entomolo/museum/indian.html

The adult moths are 7-9mm long and have a wingspread of 20mm. The forewings are pale grey with the outer portion of the wing a reddish-brown to copper colour. The adults are often seen flying around lights in the house in the evenings.

The female moths lay up to 300 eggs just below the surface of stored grains and other food materials. Eggs may be deposited through cotton or jute bags containing food. The larvae are dirty white in colour, but may be yellow, pink, brown or green, depending on the source of food.

The larvae are superficial feeders and leave silk trails

© http://www.uark.edu/depts/entomolo/museum/indian.html

wherever they crawl. When an infestation is heavy, food materials may be completely matted with webbing. Often prior to pupating, the larvae wander from the food source. They may be observed crawling on ceilings or around the cupboard, away from the original food source. Complete life cycles may take from 27 to 305 days, depending on environmental conditions such as temperature. There are generally 4 to 6 generations per year, but under favourable conditions there may be 7 or 8.

CONTROL

Non-chemical:
1. A wasp parasite, Bracon hebetor, naturally helps keep outbreaks of Indian meal moths in check.
2. Locate sources of infestation and remove the packages from the household or building.
3. Food such as birdseed can be heat treated above 60ºC or placed in freezers below 0ºC to kill the insects.
4. Un-infested packages should be stored in sealed containers to avoid infestation. Wash shelving and cupboards to remove any eggs, stray larvae and cocoons. Kill any adult moths found.

Chemical:
Remove all food products from the cupboards prior to spraying. Remove all cocoons and food debris from the shelves and cracks behind the shelving. Treat all areas with a residual insecticide (available in hardware stores, grocery stores, nurseries, etc.).

W.A. Attwater

PDCF-009 (Revised 2003/11/07)