| Two types of insects are responsible for damage to wool clothing, wall
hangings, feathers, silk garments, felt, furs, wool rugs and carpeting. In
Wisconsin there are two species of clothes moths and several species of
carpet beetles that attack natural fibers. Most damage is done during
storage because these insects are most active in dark, undisturbed areas.
Carpet beetles are responsible for 80% or more of the woolen damage we see
in the Insect Diagnostic lab. Every home has some carpet beetles and they
commonly breed outdoors. Carpet beetles can be found in most bird and wasp
nest, and in attics, closet floors, along baseboards, in heating ducts and
cold air returns, inside wall voids and in furniture and appliances where
they feed on dead insects, animal hair, dead animals (mice or birds), food
crumbs, pet food, seeds, spices, household lint and some dry goods. They
will feed on wool, silk, furs, and any clothing soiled with blood, urine,
beer or food stains.
The damaging stage are small, brown, bristly or hairy, slow moving,
segmented larvae that are 1/5 inch or less in length. An average life cycle
takes one year but can vary from 4-36 months. Larvae can grow backwards
(called retrogressive molting),if deprived of food. This adaptation allows
carpet beetles to live for months without food. Adults are not damaging and
feed on flower pollen. Females lay fragile eggs singly near food sources
that hatch within 2-3 weeks.
Feeding damage appears as small irregular holes. Fabric strands are clean
cut with little associated debri, dust or and webbing . You can sometimes
find the brown, cast larval skins nearby. Damage will be common on
undersides of wall hangings, beneath furniture, in unvacummed closets, and
on the underside of folded clothing stored on the floor or shelving.
Casemaking (Tinea pellionella) and webbing clothes moth (Tineola
bisselliella) numbers have increased in recent years due to the
dramatic increase in infested imported, woolens and Oriental carpets. Adults
are small 1/3 inch yellowish tan to buff colored moths that rarely come out
into lighted areas. The damaging stage is small white caterpillars with dark
heads. The casemaking clothes moth caterpillar spins a protective cigar like
case from silk and material fibers. Damaged areas appear as small holes that
have webbing, debri covered cocoons and small pellets mixed in.
CONTROL
If large numbers of fabric pests are seen, search for a hot spot as the
source. Infested wallhangings, pet food, wasp nests, wool yarn stored under
bed frames, furs, or accumulations of dead insects material. Other sources
include old furniture with horse- hair padding, and homes built during the
1920 and 30's that commonly used animal hair mixed with plaster.
Prevention is easy when storing articles in tight fitting garment bags or
plastic storage containers. All garments should be cleaned before storage.
Consider using plastic or zip lock bags to store sweaters in dressers.
Storage cartons can be sealed with good quality tape, All seams and joints
should be taped over. Vacuum closet floors, shelves and dresser drawers
before putting clothing away for the summer. Furs can be professionally
cleaned and place in cold storage for protection.
Good housekeeping will remove, lint, dust, or hair . Be sure to move and
vacuum under furniture if you have wool rugs, and the 1/2 inch space along
baseboards that is missed by many vacuums . Areas that are frequently
vacuumed do not become damaged., behind heaters, and in.
Cedar oil, cedar chips and cedar closets have generally been overrated as
a control of wool pests. Very young larvae of clothes moths that are exposed
to high concentrations of cedar oil vapor are killed, but older larvae,
adults and most carpet beetles are not affected by the oil. Cedar lumber in
closets or chests will lose oils over time and after 3 years are useless in
killing any fabric pest. The advantage of tight fitting, well constructed
cedar chest is that it make it difficult for insects to get to the clothing.
If you have found a problem, vacuum or brush the insects off the article.
Washing or dry cleaning will kill all life stages. Freezing is an option if
the article has been kept at room temperature before the treatment. Place
articles in freeze or in plastic bags, (with air removed and loosely
packed,) expose to below zero for 72 hrs. Clothes moths and carpet beetles
can survive in unheated attics, bird nests, wall voids and other sites if
they have a chance to acclimate to slowly falling temperatures. The shock of
going from 70 to near 0 is what kills the insects. Heating articles above
130o F for 1 hrs will also kill all life stages.
Direct spaying of fabric with insecticides or moth proofing agents is
always a risk because of staining, discoloration, shrinkage weakening
fabrics , and other chemical reactions caused by water, solvents or the
chemical themselves. These chemicals are also difficult to find. There are
clothing sprays that contain pyrethrum, permethrin, allethrin or resmethrin.
A wider selection of insecticides are registered for carpet treatment but
the same care is needed.
Moth balls (naphthalene) and PDB (paradiclorobenzene) change into gases
and work as fumigants, but are ineffective as repellents . To be effective,
they must be confined in a closed system with little air movement such as a
sealed plastic box. Hanging these products in a closet will usually not
build up to toxic levels, or if they do there is concern if people are
breathing that much vapors. Clothing will need to be aired before use. |