Beetles Identification Guide

Sexual dimorphism: Sexes are externally similar.
Distribution: Throughout most of the temperate regions. The species was
introduced in North America around 1850; it occurs in Canada from coast
to coast.
Economic importance: This species is found occasionally in flour mills and warehouses
but is best known as a household pest. The larvae feed on a wide variety
of materials of animal origin such as wool, fur, and skins. They also cause concern
by attacking dried insect collections and, in some countries, by destroying
cocoons of silk worms. Hinton (1945) considers this species to be the most important
pest of insect collections in temperate regions, if not around the world.
In Canada the species is abundant in coastal areas of British Columbia, occasional
in Ontario, and rare in the other provinces (MacNay 1974).
Attagenus unicolor (Brahm) (synonyms: A. piceus Olivier, A. megatoma Fabricius)
black carpet beetle
attagène des tapis
Diagnosis: This dermestid differs from the species of Megatoma, Reesa, and
Trogoderma included here, with which it may be confused, in having the antennal
cavity of the prothorax broadly open posteriorly with the first segment of the
hind tarsus half as long as the second.
Halstead (1981) recognized three subspecies of A. unicolor: A. unicolor
unicolor widely distributed in the world, A. unicolor japonicus Reitter (synonym:
A. unicolor canadensis Casey) occurring in the oriental part of the Palaearctic
region and introduced in the Nearctic region, and A. unicolor simulans Solskij
known from Afghanistan, Central Asia, and Sinkiang Uighur in China. Adults of
A. unicolor unicolor differ externally from those of A. unicolor japonicus in having
the pronotum and elytra almost entirely covered with dark setae, whereas in A.
unicolor japonicus the sides and base of the pronotum and the base of the elytra
have distinctive golden brown setae.
Two other species of Attagenus occurring in North America warrant mention
here, since they could be of economic importance in Canada. Attagenus
pellio (Linnaeus) is a cosmopolitan species known in Canada from a few specimens
collected in Nova Scotia, Quebec, Ontario, and British Columbia. The
species has not been recorded as a pest in Canada, except for the report by
Fletcher (1903), stating that it damaged carpets in Nova Scotia. In Europe the
species is known as a major household pest, feeding during its larval stage on
materials of animal origin such as wool, fur, and skins. It also occurs in warehouses,
where it probably subsists mainly on the remains of insects, and has been
recorded damaging museum specimens, particularly dried insect collections.
Adults of A. pellio differ from those of A. unicolor mainly in having a contrasting
tuft of white setae near the middle of each elytron.
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