Varied And Common Carpet Beetles
Order:
Coleoptera
Family: Dermestidae
Scientific Name: Anthrenus
verbasci - Varied Carpet Beetle & Anthrenus scrophulariae -
Common Carpet Beetle
The varied and common carpet beetles are frequently found in structures and readily attack a wide variety of animal and plant products, such as carpets, fabrics, feathers, hair, dead insects, processed foods and spices. Both species are distributed throughout the United States, although common carpet beetles occur more frequently in northern states. The presence of carpet beetles may indicate that there is, or was, another pest problem involving rodents, birds or insects.
Description
The
adult beetles are oval in shape and are from 1/16 to 1/8 inch (1.8 to
3.2 mm) long.
The head is concealed from above, has a median ocellus and the
antenna is short with a three-segmented compact club.
Varied carpet beetles are black, with yellow and white scales on
the pronotum and elytra (wing covers), the latter having two transverse
zigzag bands of white scales bordered by yellow scales.
The underside of the body is covered with grayish yellow scales.
Common carpet beetles are differentiated by the presence of a continuous
series of brick-red scales along the inner margin of the elytron forming
a median line when at rest.
The wedge-shaped larvae are dark brown to black and are covered
with numerous brown hairs, some of the hairs are spearheaded (hastisetae)
and form large tufts or clusters which project rearward.
Life Cycle and Habits
Carpet beetles undergo complete metamorphosis, with the larval stage causing the majority of the damage to infested products. The life cycle of the varied carpet beetle usually requires 249-354 days. Approximately 40 eggs are laid in various locations, not necessarily on the larval food. The larvae generally require 222-323 days prior to pupation, which lasts 10-13 days. Adults live for 14-44 days and in the warm months are found outdoors feeding on plant pollen.
The common carpet beetle has a much shorter life cycle requiring only 77-110 days. Approximately 60 eggs are laid on a suitable larval food source. Larvae require 60-80 days, followed by pupation which lasts approximately 7-12 days. Adults live for 20-30 days and have habits similar to the varied carpet beetles.
The larvae of both species are often found considerable distances from the larval food source, and when disturbed erect their setal hair tufts and curl up into a ball. Adults hatching indoors initially avoid light, whereas adults emerging outdoors are readily attracted to light. Adults are strong fliers and are, therefore, able to enter structures through attic openings.
Control
The initially step in carpet beetle control is correct identification of the pest, followed by a thorough investigation to identify and eliminate the sources of the infestation.
All infestible materials of natural origin should be examined. Sanitation, including removal and/or treatment of the infested material, is the first step in remediating the problem. Residual insecticide application to cracks and crevices and the immediate area around an infestation site should be made with an appropriately labeled product. In cases where the infestation is originating in a wall void or other accessible space, the use of a dust formulation provides longer residual activity.
The
exterior of the structure should be inspected for plants that attract
these dermestids, and they should either be removed or treated with an
appropriately labeled pesticide.
During the warmer months, perimeter foundation treatment with a
wettable powder or microencapsulated insecticide formulation reduces the
number of beetles entering the structure. Carpet beetle infestations are often persistent and may require
several follow-up visits to resolve the problem.
(Courtesy of the National Pest Control Association.)