BLACK CARPET BEETLE
Common Name: Black carpet beetle
Scientific Name: Attagenus unicolor
Introduction. The black carpet beetle is the most commonly encountered and economically important of the carpet beetles. Its common name comes from its typical all-black color. This species has been cited with respect to allergic responses in humans. It is found throughout the United States, but more commonly east of the Rocky Mountains and in the northern states.
Recognition. Black carpet beetles measure 1/8 to 1/4 inch long and are dull dark brown to black. The beetles are elongate-oval in shape with the head more or less concealed from above.
The larvae are light brown to black, carrot-shaped, and tapering towards the rear. They are covered with golden brown to dark brown hairs laying flat on the body. From the rear end protrudes a long tuft of brown hairs that is nearly as long as the body. Mature larvae measure up to 1/4 inch long.
Similar beetles. (1) Related beetles of the Family Dermestidae are not uniformly dull black, but have variable patches of fine orange, tan or yellow hairs or scales on the hardened front wings (elytra). (2) Anobiid powderpost beetles are brown and have numerous longitudinal ridges on the hard, front wings (elytra) that cover the rear thorax and abdomen.
Damage and Signs of Infestation. Infested fabrics typically have much surface damage and holes here and there, but larvae can cause large irregular holes in material. Furs have the hairs cut at the base but no damage to the hide, giving the hide a bare appearance, and no webbing present. Larval caste skins are often present. Droppings (frass) are minute, irregular in form, often the color of the material being damaged.
The larvae may burrow through packaging materials when seeking food.
Biology. The female lays about 90 eggs (range 42 to 114) in dry animal remains and in lint which has accumulated in dark and secluded places such as behind and under baseboards, in cracks and crevices, in air ducts wall voids and attics. Eggs hatch in 5 to 16 days. Larvae usually molt 5 to 11 times, but may molt up to 20 times under unfavorable conditions, over a period of usually 166 to 330 days (range 166 to 639). The larva pupates in the last larval skin and pupation last 6 to 24 days. Developmental time (egg to adult) usually takes 177 to 370 days (range 177 to 679).
Habits. Black carpet beetle larvae are general feeders on both dried animal and starchy plant materials. Animal-origin materials include hair, fur, feathers, hides, horns, carcasses, and dead insects, and they can be found in bird, rodent and insect nest. Plant origin materials include cereal, stored grain, nuts, seeds, cayenne peppers, various meals, and processed foods, such as flour.
On fabrics, larvae tend to surface graze but are quite capable of making small or large irregular holes. On furs, they cut the hairs at their bases and leave the hide undamaged. The larvae may burrow through packaging materials to get to the contained food.
The adults are found outside and active during warm weather. They are found on flowers, particularly in the spring and especially on Spiraea shrubs, often eating the pollen. They can also be found in the nests of birds, rodents, and insects such as wasps, and around spiders. Inside, adults are often found at windows during the spring. The actual breeding areas can be quite diverse and may include unusual places such as wall/ceiling voids where cluster flies, boxelder bugs and other overwintering insects have died and where social insects built nests and died, such as yellowjackets and honey bees.
Other food sources and breeding sites include rodent baits in attics, crawl spaces, and basements, wasp and hornet nest in attics or under eaves, bird nests built in or outside against buildings and light fixtures containing dead insects. The larvae tend to wander about feeding here and there, and can be found far from the primary infestation. When disturbed, the larva curls up and “plays possum”. The adults are attracted to light upon emergence from the pupa, but shun light after mating. The larvae avoid light as well.
Cultural Control & Precautionary Measures. The key to controlling black carpet beetles is to find the primary sources of infestation and eliminate them. Besides the obvious woolen carpeting, clothing, furs, fabric-covered furniture, and stored products, it may be necessary to check for the more unusual sites such as listed above. Consider sites that may contain the remains of overwintering and nesting pests (like cluster flies, boxelder bugs, mice, sparrows and starlings).
The thorough inspection should be followed by good sanitation practices, pest-proofing measures, and pesticide application by a professional, when required. Museum specimens and valuable collectibles may be treated with the use of heat (140 °F core temperature for 30 minutes) or cold (0 °F core temperature for 72 hours) if appropriate and non-damaging to the infested item(s). Exposed beetles, larvae and frass can be removed using a vacuum cleaner fitted with a hose attachment.
Professional Control. A Rottler technician will seek out and expedite removal of all visible, accessible breeding sites for black carpet beetles. Spot treatments, crack and crevice applications and/or structural void injections with appropriate insecticides may be made to facilitate beetle elimination and help prevent reinfestation.
Locations
Serving the St. Louis Metropolitan area since 1956, including
Arnold, Ballwin, Chesterfield, Crestwood, Creve Coeur, Des Peres,
Fenton, Florissant, Kirkwood, Maryland Heights, Overland, St.
Charles, Webster Groves, Wentzville and surrounding areas.
In Illinois: Belleville, Collinsville, Edwardsville, Columbia,
Madison, Waterloo, O’Fallon, Granite City, Alton, St. Clair, Monroe
and surrounding areas.
Columbia & Jefferson City, MO and surrounding areas.
