Hello and thank you for your interesting question.
I've made this answer maybe a little longer and detailed than you
might have expected. Here's the answer in a nutshell: The worms are
the larvae of clothes moths. The best way to avoid damage is to keep
the sweater clean, try to eliminate other sources of food for the
larvae, and either use the traditional moth-balls or but a
fabric-treatment from the Off! Company called Moth Proofer. You
should be able to buy that at Walmart and similar stores.
Okay, I'm going to give you some backgound on Merino wool and also on
the common worms - - actually clothes moth larvae -- that tend to eat
holes into wool goods. Then I'll give you the detailed answer you
seek -- how best to protect one from the other.
1. Merino Wool:
"Wool is one of the oldest fibers known to man. Fragments of woolen
cloth have been uncovered in tombs and ruins of Egypt, Nineveh and
Babylon, in the barrows of the early Britons, and among the relics of
the Incas and Aztecs.
As early as 200 B.C., the Romans began to improve their flocks. These
sheep were introduced to Spain, where they became the famous Merino
breed. Towards the end of the 18th century, sheep were imported to
Australia, which today is the major sheep-producing nation."
Wool For All Seasons
"Today in apparel, the demand is for extra-fine wool with a diameter
of 13 to 19 microns, referred to as Super 150's, and fine wool, of 19
to 23 microns, Super 100's. Both grades come from Australian and New
Zealand Merino breeds."
2. Clothes Moths and Their Larvae:
"If wool has any fault, it is its propensity to be eaten by a number
of insects, including moth larvae and carpet beetles. However,
full-grown moths are not responsible for the unpleasant holes. The
fibers are essentially comprised of protein, a highly desirable food
source for larvae. Smash the full-grown ones flying about all you
like--by that time it will already be too late."
The Moth Myth
Clothes-Moth is a general name for a great variety of small, so-called
Tineine moths, the larvae of which feed mainly on dried animal
substances, and are very destructive to woollen goods, furs etc.
Here is a picture of a clothes moth and the eggs it lays
And here is a picture of the 'worm'
Webbing Clothes Moth: Larva and Larva Damage
SIZE: Less than 1 inch
COLOR: Yellowish to gold-colored
DESCRIPTION: Clothes moths are small, yellowish to slightly
gold-colored moths with narrow, slightly pointed wings. They are not
attracted to lights and usually hide when disturbed.
HABITAT: In houses where wool is available; also, in the wild.
3. Protecting Merino Wool From Damage By Clothes Moth Larvae (Worms)
"There are a variety of preventative methods to keep insects from
attacking your wool garments. Before storing them for any length of
time, be sure to thoroughly clean them. Cedar wood is a good natural
deterrent, and wicker baskets are reputed to be excellent containers.
Ideally, your wool garments should be placed into cotton bags, which
allows the textile to breathe, and then sealed. Plastic bags and bins
are not a good idea because they don't allow air circulation. Any
moisture remaining in the container will result in a musty smell at
best, and possibly even mold or mildew damage.
The Moth Myth
LIFE CYCLE: Female webbing clothes moths lay 40-50 eggs that hatch in
4 to 21 days. Larvae like to feed on soiled material, spinning silken
mats or tunnels and incorporating textile fragments and bits of feces
into the contruction. The life cycle is about 65 to 90 days.
TYPE OF DAMAGE: Clothes moths can feed on wool products, such as
clothing, carpets, rugs, furs, fabrics, blankets, and piano felts.
They may feed on fabrics of vegetable origin (cotton) if the fabrics
are mixed with wool or soiled with food particles. Clothes moths can
do serious damage to small or large wool rugs. The caterpillars can
feed on the underside of the rug for a long time-doing considerable
damage-before they are detected.
CONTROL: Articles must be protected from clothes moth attack, either
by frequent cleaning or storing in insect-free environments. Wool rugs
should be inspected and cleaned (if small enough) on a regular basis.
INTERESTING FACTS: Most damage is done to clothing and fiber left
undisturbed for a long time or to clothing soiled with beverages,
urine, oil, and sweat.
"Proper diagnosis of the pest is the first step in gaining control.
Woolens damaged by the clothes moth exhibit furrows in the surface,
which is caused by the larvae's habit of grazing. Occasionally, and
during heavy infestations, the woolens will have holes. When larvae
infest furs or hairbrushes, they clip off the individual hairs close
to the surface. Larvae can infest cast pet hairs that are trapped
under baseboards or in the air return vents of heating systems. They
also have been found in vacant wasp nests and feed on insects that
have died in wall voids or attics.
"The webbing clothes moth will feed on hair, wool, fur, feathers, and
similar animal products. Synthetics, cottons, and other plant
materials are not attacked by the webbing clothes moth larvae unless
these items are stained with food or body oils. The casemaking clothes
moths will attack any of the following: felts; dried carcasses or
taxidermy mounts; wool clothing, carpets, or tapestries; feathers;
furs; and plant-derived materials such as dried herbs, tobacco, tea,
hemp, pharmaceuticals, and seeds and seed products.
"If infested, clothing, blankets, and tapestries should be laundered
or dry cleaned. ... Before using any pesticide, thoroughly read the
label and do not apply to any carpet, upholstery, or other site unless
it is specifically listed in the directions for use."
"Good housekeeping is critical for preventing or controlling clothes
moth damage. Never allow clothing, rugs, etc. to lie in a neglected
pile. Regular use of a strong suction vacuum cleaner with a crevice
tool to remove lint, hair, and dust from floor cracks, baseboards, air
ducts, carpets, and upholstered furniture is necessary. Keep closets
and dresser drawers clean. Regularly clean rugs where they fit close
to the baseboards and under the quarter round. Inspect stored foods
and eliminate bird nests and dead rodents. Launder and dry clean or
steam clean clothes and other items before storage. Egg-laying clothes
moths are attracted to soiled articles. Ironing will also destroy all
stages of clothes moths. Sun, brush, and expose clothing to the
weather. Outdoors, bright, hot sunlight, and wind will reduce larvae
and damage. Frequent use of woolens and other animal fiber clothing
almost assures no damage from clothes moth larvae.
"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."
Preventing Damage To prevent an infestation of clothes moths (and
carpet beetles, another fabric pest), housekeeping is important.
Removing dust and lint will eliminate breeding and egg laying sites,
particularly on rugs, on carpets next to walls and under furniture and
around registers and ducts, baseboards, etc.
Clothes Storage Inspect clothing and storage areas in the spring for
potential infestations. Dry clean or launder all clothing before
storing (as soiled clothes are more attractive). Store clothing in
tight boxes or chests (we suggest NOT using plastic bags). Along with
the clothing, place mothballs or crystals (naphthalene) or part of a
no-pest strip. Despite their reputation, cedar chips, cedar chests and
cedar closets are overrated as a control of wool pests. Even high
concentrations of cedar oil (e.g., fresh lumber and lumber recently
treated with cedar oil) only kill young larvae; older larvae and
adults are unaffected.
A less smelly alternative to mothballs is formulation of lavandin
oil, which repels clothes. An example of a product that contains
lavandin oil is OFF! Moth Proofer, which is marketed by the SC Johnson
Company. This product will protect items from clothes moths for a
single storage season. In addition to eliminating the mothball smell,
OFF! Moth Proofer also eliminates the risk of accidental poisoning
(either by inhalation of ingestion) by naphthalene or para-dichloro
Yard & Garden News
Search terms used:
merino wool moth superfine
OFF! Moth Proofer johnson
Thanks again for your question. If you find any of this answer
unclear, please request clarification. I would appreciate it if you
would hold off on rating my answer until I have a chance to reply.
Google Answers Researcher