in grain storage; but if whole corn is brought into
last half coppery with
homes or stores, sooner or later these moths are likely
dark bands. These
to become pests and fly about.
moths can fly short
distances indoors.
Active flight for several
days wears off most of
the colored scales, but
their gray band and coppery scales can be seen using
a hand lens.
LESSER GRAIN BORER
Larvae, or caterpillars, grow to be about 1/2 inch
long, cream colored (sometimes pinkish or greenish)
Rhyzopertha dominica
with a brown head. Although not easily seen, fairly
A small cylindrical brown beetle about 1/8 inch
long hairs grow sparsely on each larval segment; when
long, this beetle is an important damaging pest of
the larva is in a dusty environment, small particles will
grain in storage or transport (trains, ships, etc.). Like
stick to the hairs. The Indian meal moth's life cycle is
many of its relatives (the Bostrichids, most of which
about two months.
are wood borers), the Lesser Grain borer has strong
Infestations in
jaws and can chew through seed coats into grain where
packaged products
it completes its life cycle. This beetle is rarely a
problem in urban homes or stores.
numbers; the longer the product is kept without use the
larger the population grows. Larvae spin silk from
their lower lip wherever they go. In large numbers,
SEED BEETLES OR PEA AND BEAN
they can cover the top of a product with silk as they
WEEVILS
wander around on the surface. As a population grows,
larvae may wander outside the package [often for long
These beetles are not true weevils and do not have
distances: from a room in lower levels, through holes
the weevil snouts. They infest only the seeds of one
in the floor into upper areas, from a pantry to the
large plant family, the Legumes: peas, cowpeas, most
ceiling]; they may dangle from ceilings on silk strands.
beans (including mung beans). Each of these pests
Their numbers, wandering habits, and large size easily
specializes in seeds of only one kind.
distinguish Indian Meal moth larvae from the tiny
Most species measure 1/8 to less than 1/4 inch
Clothes moth larvae that do not wander openly. A
long. They are rather broad and have light and dark
pheromone that specifically attracts the flying Indian
markings. They lay eggs on beans; larvae bore inside,
Meal moth is a very effective monitoring tool to use in
devour the middle, then emerge through obvious 1/8
warehouses and food service or retail sale food stores;
inch holes. The pest can be a problem in restaurants
in large areas, pheromone trap results reveal infested
and homes. Infested and potentially-infested legume
areas.
seeds should be discarded.
Indian meal moths infest most milled or ground
cereals such as flour and cornmeal; all starchy
processed products such as crackers, cake mixes,
PESTS OF GROUND, MILLED, OR
pasta, dog food, and rodent bait. They particularly
PROCESSED GRAIN, SPICES, SEEDS
respond to nut meats like pecans and walnuts, nuts in
AND NUTS
candy, powdered milk, some spices, and dried fruit.
This large group of pests [Some are called, "bran
Products stored or unused for a long time are always
bugs."] infests stored products that have seed coats
primary suspects for infestations.
that are broken or removed by processing. [Potential
Control and management of these pests is the
infested products are listed with each species.]
same as that for the Saw Toothed Grain Beetle (see
below).
INDIAN MEAL MOTH
SAW-TOOTHED GRAIN BEETLE
Plodia interpunctella
Oryzaephilus surinamensis
The Indian meal moth is a small colorful moth.
Sitting on a wall, it is 1/3 inch long (somewhat longer
The saw-toothed grain beetle is a tiny, slender,
with wings folded backward). The head and thorax is
dark-brown beetle that measures a little under 1/8 inch
brown; the basal half of the wings are gray, and the
long. With a good hand lens, a pesticide applicator can
Module One, Chapter 4, Pg 3