The varied carpet beetle probably gets its common name because
there is great variation in the color pattern on its dorsal
surface. This species is known to cause dermatitis in humans.
It is worldwide in distribution and is found throughout the
Adults about 1/16-1/8" (1.8-3.2 mm) long. Body black,
with pattern of yellow and white scales on pronotum and elytra
(wing covers), 2 transverse zigzag bands of white scales bordered
by yellow scales on elytra; scales elongate, 2-3 times as
long as broad; lower/underside of body covered with grayish
yellow scales. Antennae short, with 3-segmented, compact club.
Posterior end of elytra evenly rounded. Abdominal 5th sternite
broadly and deeply emarginate (notched) epically. In addition,
body oval, head more or less concealed from above, with a
median ocellus, and tarsi 5-5-5.
length up to 1/4" (4-5 mm). Stout, widest posteriorly.
Color dark brown to black. Covered with brown hairs; with
tufts of spear-headed hairs (hastisetae) arising from membranous
areas on the sides of abdominal segments 5-6-7 pointing towards
the rear and converging towards the center, heads of spear-headed
hairs of hind tufts equal in length to combined length of
7-8 preceding segments. Antennae with segment 2 less than
2.5 times as long as broad. Abdominal sternites entirely membranous.
(1) Carpet beetle (Anthrenus schrophulariae) with brick red
scales along midline of elytra (wing covers). (2) Furniture
carpet beetle (Anthrenus flavipes) with pronotum and elytra
patterned with white, yellow, and brown scales, underside
of body pure white, posterior end of elytra with shallow notch
at midline. (3) Other dermestids (Dermestidae) with less compact
antenna! club of usually more than 3 segments, hairs on dorsal
surface somewhat flattened but not scalelike, and/or 5th abdominal
sternite not deeply notched epically. (4) Powderpost/deathwatch/anobiid
beetles (Anobiidae) with antenna longer, if clubbed, then
club asymmetrical (lopsided). (5) Other beetles with oval
body form lack a median ocellus and/or lack scalelike hairs.
AND SIGNS OF INFESTATION
Fabrics typically have much surface damage and holes here
and there, but larvae can cause large irregular holes in material.
Furs and brushes have mostly the tips of hairs damaged, leaving
uneven areas. With museum insect specimens, the accumulation
of fine powder/frass beneath the specimen is often the only
indication of these beetle's presence. Larval caste/molt skins
are often present. Frass/droppings are minute, irregular in
form, often the color of the material being damaged. The larvae
may burrow through packaging materials when seeking food.
Females do not always lay their eggs on larval food material.
The eggs hatch in 17-18 days. The larval period ranges from
222-323 days but may last up to 623 days under adverse conditions
of temperature, humidity, and food, and requires an average
of 7-8 molts (range 5-16). The larva pupates in the last larval
skin and pupation lasts 10-13 days. Developmental time (egg
to adult) usually requires 249-354 days at room temperature,
but may take as long as 2-3 years depending on temperature
and food. Adult males live 13-28 days whereas, females live
case of dermatitis occurred in a man over a 5-year period
due to hypersensitivity to an infestation in his bedroom carpet.
Inhalation of large quantities of the larval spear-headed
hairs may cause pulmonary irritation; Anthrenus spp. are known
to cause this condition.
Varied carpet beetle larvae feed on a wide variety of animal
and plant products. Animal-origin materials include woolens,
carpets, furs, hides, feathers, horns, bones, hair, silk,
fish meal, insect pupae, and dead insects. Plant-origin materials
include rye meal, corn, red pepper, cacao, cereals, etc. Their
favored foods are insects and spiders which makes them a major
pest of museum collections and buildings with cluster fly,
boxelder bug, etc. problems.
fabrics, larvae tend to surface graze but are quite capable
of making small or large irregular holes. On furs and bristles,
they damage mostly the tips leaving uneven areas. On dead
insects, they typically feed from within and the accumulation
of fine powder/frass beneath the specimen is usually the only
indication of their presence. The larvae may burrow through
packaging materials to get to the contained food.
are found outside during warm weather. They are often found
on flowers, particularly in the spring and especially on Spirea
spp., where they often eat the pollen. Females seek out the
nests of bees, wasps, and spiders as oviposition sites, as
well as bird nests. Inside, adults are often found at windows
during the spring.
primary breeding areas are quite diverse and may include obscure
or unusual places such as wall/ceiling voids where yellow
jackets, honey bees, etc. Dived or where cluster flies, boxelder
bugs, etc. over wintered, rodent bait left in attics, crawl
spaces, or basements; wasp and hornet nests in attics, under
eaves, around windows, etc.; dead insects and spiders in the
attic or in light fixtures; behind and under baseboards where
lint and hair accumulate; animal trophies or rugs; insulation
which contains animal hair; dead animals in the chimney flue;
etc. In such places, the larvae feed on the animal and/or
plant material present.
larvae tend to wander about and can be found far from the
primary infestation. When disturbed, the larva erect their
hair tufts and spread the bristles and hairs, forming a ball.
hatching from indoor pupae avoid or shun light until egg laying
is mostly complete, and then become attracted to light. Most
outdoor adults show an attraction to light.
The key to controlling varied carpet beetles is to find the
primary source(s) of infestation and eliminate it/them. Besides
the obvious clothing, furs, drapes, carpeting, and stored
products, it may be necessary to check for the more unusual
places such as those listed above. Ask the customer about
both current and past occurrences of flies in the winter,
boxelder bugs, rodent problems, birds nesting on/in the building,
thorough inspection should be followed by good sanitation
practices, and pesticide application when required. Museum
specimens may be treated with heat and/or cold if applicable
(be careful of possible damage to specimens) or with fumigants.
Refer to the control section under the general treatment of
fabric and paper pests for details.