Meal Moths
The most observable life stage of the Indian moth is
the adult. It can be observed flying around the inside of
the house or apartment. The moth is small with a wingspan
is of 1/2". The coloration of the moth is very distinct.
The wings are dull gray in background with the wing tips
a copperish reddish brown. When the moth is resting, the
wings are held tightly to the body. When observed flying
in the household the Indian meal moth is often mistaken
for a clothes moth. Clothes moths are smaller (1/4"
wingspan), dull gray with no distinctive markings.
The Indian meal moth caterpillar is about a half
inch long when fully grown and is dirty white, sometimes
with greenish and pinkish hues.
The larvae (caterpillars) cause all of the damage.
They are general feeders and commonly infest grains and
cereals, grain and cereal products, cornmeal (Indian
meal), graham flour, dried fruits, nuts, chocolate,
cookies and dried pet foods and animal feeds. Less
commonly, they may also be found in powdered milk,
candies, beans and peas, ground chili pepper, garlic,
dried meat, dried mushrooms, garden seeds and beehive
products.
Damage to stored food by the caterpillars greatly
exceeds the amount of food actually eaten because the
larvae spin large amounts of silk as they travel and
feed. This webbing is often dense enough to attract
attention when stored products become heavily infested,
and makes the food worthless. Mature larvae usually leave
their food when it is time to look for pupation sites. As
a result they are often seen climbing up walls and
cupboards. An infestation can also be suspected when the
adults are seen flying to lights in the kitchen and other
rooms of the house. The moths are very active during the
evening and night-time hours; they are commonly attracted
to television screens at night.
A second meal moth sometimes found in the home is
the Mediterranean flour moth. This moth appears similar
in body shape to the Indian meal moth, but the wings are
leaden gray with wavy black markings (definitely not bi-
colored). The Mediterranean flour moth has a
characteristic pose when resting: the front of the body
is raised, giving the wings a distinct downward slope,
with the tip of the abdomen protruding up between them.
The habits and biology of this species are similar to
those of the Indian meal moth. This species prefers flour
and meal, but also infests grain, bran, cereal products
and other foodstuffs.
The common meal moth, is the third species which may
be found in houses. It is the largest of the three
species, having a wingspread of about 1 inch. The body is
brownish an the wings are light brown with dark brown
patches at both the base and tip, with two distinct,
white, wavy lines separating the two shades of brown. The
larvae (caterpillars) of this species prefer cereals,
cereal and grain products, hay and many types of dried
vegetable matter, especially if the foodstuffs are damp
or subject to high humidity. The larvae are also large,
about an inch, and they have distinctive black heads.
Integrated Indian Meal Moth Management
Purchase susceptible foodstuffs in quantities that can
be used in a short time: less than 2-4 months, if
possible. When purchasing packaged food, be certain the
containers are not broken or unsealed. Check the package
for a freshness date. Once food is in the home, use older
packages before newer ones, and opened ones before
unopened ones. Storing dried foods in a freezer will
prevent pest development. Keep food storage and
preparation areas clean at all times; spilled and exposed
food attracts insects.
Once an infestation of meal moths is suspected,
prompt action is important in preventing losses of large
quantities of stored food products. The following steps
will be useful in bringing an infestation under control.
(1) Carefully examine all susceptible foods and other
stored products that may have been exposed to the
infestation. This includes all pet foods and seeds. Do
not overlook unopened paper and cellophane wrapped
products, as the insects may even be found in these. You
will probably want to throw away all infested products.
While Indian meal moths can be killed by heating (140
degrees F for 1 hour) and Mediterranean flour moths can
be killed with cold (0 degrees F for 2 days), there is no
easy way to separate the insects from the food products.
(2) Contents from all packages (opened or unopened)
which appear to be uninfested should be transferred to
glass or plastic containers with tight-fitting lids. It
is possible that eggs were laid in these products and
that they may hatch later and lead to an infestation if
not contained. Glass containers make periodic examination
of the food easier.
(3) Remove all food, food containers and utensils from
the infested areas and clean thoroughly, first with a
vacuum cleaner and then with soap and water. Special
attention should be paid to cracks, crevices and corners
(including under and behind appliances) were bits of
flour, meal or other food may have accumulated.
(4) We do not recommend using an insecticide.
For a complete listing of suggested control options for
all home, yard and garden insect pests see: Michigan
Insect Pest Management Guide, 1991.
These kinds of publications are available from your
local Cooperative Extension Service. Read and follow
instructions on the pesticide label. Heed all warnings.
Check with your physician if you have any concerns
regarding your personal health.