The Indianmeal moth was given its common name by an early
entomologist (Asa Fitch) who found it feeding on cornmeal
(Indian meal). It is probably the most encountered pest of
stored products found in the home and in grocery stores in
the United States. Of Old World origin, it is now found worldwide.
Adults with wingspread (wing tip to wing tip) about 5/8-3/4"
(16-20 mm). Wings pale gray but front wing with outer 2/3's
reddish brown with a coppery luster.
larva usually about 1/2" (range 9-19 mm) long. Usually
dirty white but color may vary to a greenish or pinkish or
brownish hue depending on its food, with head and prothratic
plate/shield yellowish bron to reddish brown. With 5 pairs
of well-developed prolegs on abdomen and each bearing crochets
tubercule (wartlike area between spiracle and front edge of
segment) of prothorax with 2 setae (hairs). Tubercule VI on
mesothorax (wartlike area near and above leg) with one seta
(hair). Body without pinnicula (dark or pale wartlike area
at base of hairs or setae) on mesothorax, and 1st 9 abdominal
around spiracles of about even thickness.
Carpet/tapestry moth (Trichophaga tapetzella) with basal 1/3
of front wing dark brown to black,, remainder of wing white
mottled with gray and black.
Other small moths lack front wing with basal 1/3 pale and
reainder dark, wing span of about 5/8-3/4" (16-19 mm),
and/or hind wing broader than front wing and fringed with
long hairlike scales.
Chiefly at night, the female lays 100-400 eggs, singly or
in small groups, on the larval food material during a period
of 1-18 days. Upon hatching, the larva establishes itself
in a crevice of the food material. It feeds in or near a tunnellike
case it has webbed together of frass or silk. The larval period
lasts 13-288 days, depending primarily on temperature and
food availability. When the last instar larva is ready to
pupate, it leaves the food and wanders about until a suitable
pupation site is found. There are usually 4-6 generations
per year (range 4-8), with the life cycle (egg to egg) typically
requiring 25-135 days (range 25-305).
The adults cause no damage. The larvae are surface feeders
and generally produce a lot of webbing throughout the infested
part of the materials. They are general feeders and attack
grain and grain products, a wide vriety of dried fruits, seeds,
nuts, graham crackers, powdered milk, biscuits, chocolate,
candies, dried red peppers, dried dog food, and bird seed.
They are very destructive wherever dried fruits are stored.
Preferred are the coarser grades of flour such as whole wheat,
graham flour, and cornmeal, but they can breed in shelled
or ear corn.
the larvae wander about looking for pupation sites in homes,
they are often mistaken for clothes moth larvae. Likewise,
when the moths are flying, they are also mistaken for clothes
moths. Adults are attracted to light.
follow the standard control procedures for stored product
pests but remember that pupation takes place away from the
infested food material.