THE INDIANMEAL MOTH (Plodia interpunctella); Public Enemy #1
One insect is found more often than any other on stored food and
grain in the United States. This is the dreaded Indianmeal moth
(IMM). Since they feed on any items containing grain or cereal
products, the Indianmeal moth alone is responsible for most of
the insect problems associated with the natural food industry.
Let's take a little time to find out about this guy that spends
your money so freely. This is one of the easiest stored food
insects to identify because the adults have a colorful appearance
and the larvae leave a silken webbing trail wherever they crawl.
Newly emerged adults are bi-colored and measure about 1/2"
from top to bottom.
Description
Eggs: are microscopic. Female adults lay 350-500
eggs during their short lifetime.
Larvae: Usually feed in protected areas such as the ears
on a bag or in cracks and crevices. This is the damaging stage.
The larvae can chew through bags of food and seed. These larvae
are yellowish-white in color but will take on several tints of
light green, pink and brown.
Pupa: This quiescent stage can be seen covered in a silken
cocoon. No damage occurs during this stage.
Adult: Indianmeal moths only live for 5-7 days. Their
major function is to reproduce. This is why the Pheromone traps
work so well. The male moth is very attracted to the pheromone
scent.
Life Cycle: All insect life cycles are dependent on
temperature and environmental conditions; but in the summer
months (65+° F, 18+°C) the IMM will take 5 to 7 weeks to
develop. Although this pest is not a native to the US, it has
spread throughout this country.