In
the United Kingdom, the casemaking clothes moth is much less important
than the webbing clothes moth as a pest. It can be found throughout the
country, but is most common in the southern states. It is particularly
capable of damaging hair and feathers, but will also feed on spices, tobacco,
hemp, and skins. The moth derives its common name from the small silken
case that the larva spins about its body and carries about wherever it
feeds, thrusting its head and legs out in front (see picture below). Sometimes
in a severe infestation, larvae may crawl up on a wall in large numbers,
dragging their cases behind them.
Description:
Adult
casemaking clothes moths have a 1/2-inch wingspread. The adult is somewhat
smaller and more brownish than the webbing clothes moth, and has 3 dark
spots on the wings, but the spots become less discernible if the wing
scales are worn off. Hind wings are smaller, lighter, and fringed with
hair and scales. The males are smaller and lighter in colour than the
females, and are active fliers. The females are sluggish, and fly only
for short distances. The first thoracic segment of the larva, at first
brown, later becomes black, and is divided by a longitudinal band.
Biology:
Females
live about 30 days and lay 100 to 300 eggs. The larva stage lasts 50 or
more days, and the pupal stage is passed in the case or cocoon. There
are about 2 generations a year. The larva can turn within its case and
feed on food material at either end without altering the position of the
case. If the case is removed from the larva when it is very near pupation,
the larva will die. Rarely will the larva spin a web directly on the material
on which it is feeding, but will usually attach its case to the material
by means of silken threads. Pupation takes place within the case after
both ends have been sealed with silk. There were found to be 3 or 4 generations
a year at 26 ° ± 8 °C (79 °F) and 82% ± 10% relative humidity
when larvae were fed on woollen fabrics impregnated with 5% yeast (CChem,
1956).
Control
and Treatment:
The
best way to combat carpet beetles and clothes moths is to prevent them
from becoming established in the home. The principal weapon is the vacuum
cleaner and its brush attachment. Rooms should be cleaned often enough
to prevent the accumulation of lint, hair, and other carpet beetle and
clothes moth food materials. Close attention should be given to rugs and
carpets, draperies, upholstered furniture, closets (especially those containing
woollens and furs), radiators and heaters, corners, cracks, baseboards,
mouldings, and other hard-to-reach places. If an infestation is known
or suspected, the sweepings of the vacuum cleaner should be disposed of
immediately in such a way as to destroy the insects, to prevent a transfer
of infestation from one part of the house to another.
Abandoned
nests of birds, rodents, and insects, (particularly bees and wasps) that
are in or near the house should be removed, for the larvae of both carpet
beetles and moths may feed on insect remains that they may contain. Bedding
places of pets should be kept clean. Mounted animal specimens or trophies
(or even fur-covered toys), insect collections, stored woollens, carpeting,
clothing, feathers, furs, old spices, cereals, or seeds should be examined
for signs of infestation. The attic and garage should be included in the
inspection. Avoid bringing carpet beetle adults into the house on cut
flowers, where they are sometimes found feeding on pollen.
Cedar-lined
chests and closets are not 100 percent effective. The natural cedar oil
evaporates and a fresh treatment of cedar oil should be applied every
two years. Be sure that all cloth goods be dry cleaned, washed, pressed
with a hot iron, sunned, or brushed prior to storage in an airtight container
with an effective moth repellent.
If
the infestation is particularly bad, you may have to call in a pest controller
but don't be persuaded into having a contract. Usually a Job treatment
of three or four visits is enough to get on top of the problem. A general
spray, once the infested material has been removed, in the problem area
and also the areas adjacent, in case any have gone walkabout. Infested
stuffed furniture and other salvageable commodities should be fumigated
by a licensed pest control operator or applicator. Before using any insecticides,
always read the label directions and follow safety precautions.
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