Beetles Identification Guide

Attagenus brunneus Faldermann (synonym: A. elongatulus Casey) occurs in
the Palaearctic and Nearctic regions. In North America it is widespread in the
United States and has been mentioned as occurring in Quebec and Ontario
(Campbell et al. 1989). The Canadian records, however, require confirmation.
As noted by Beal (1970), the species is found regularly in houses and has been
reported to infest dried milk, woolens, and peanuts. Adults of A. brunneus are
externally similar to those of A. unicolor but differ in that the last antennal segment
of the male is generally more elongate (about 3.0—4.0 times as long as the
2 preceding segments instead of 3.0—3.5 times as in A. unicolor).
Sexual dimorphism: Males have the last antennal segment about 3.0—3.5 times
as long as the 2 preceding segments combined; females have that segment subequal
to slightly longer than the 2 preceding ones (Fig. 250).
Distribution: Nearly cosmopolitan (Beal 1970). The species ranges in Canada
from coast to coast.
Economic importance: This species is one of the most common household pests
in North America and during its larval stage feeds on wool, fur, skins, feathers,
and other materials of animal origin. It is also found on grain spillages in grain
elevators, flour mills, and feed mills, and has been known to attack museum specimens,
particularly dried insect collections. The damage is done by the larvae,
since the adults feed on nectar and pollen. Under natural conditions, A. unicolor
occurs in nests of birds, rodents, and social Hymenoptera. The species is far less
important as a pest in Europe.
Dermestes ater De Geer
black larder beetle
dermeste noir
Diagnosis: The species is distinct from the other Dermestes included here in
having the dorsal setae predominantly black with some paler setae scattered
among them. In the other species the pronotum or the elytra has extensive
parts covered with pale, white, or golden setae.
Sexual dimorphism: Males have a tuft of setae on the middle of the third and
fourth visible abdominal sterna (Fig. 261). Females have no such tuft of setae.
Distribution: Cosmopolitan. The species probably occurs in Canada from coast
to coast.
Economic importance: Adults and larvae of this species are known to feed on a
wide variety of materials of animal origin and to be predacious on other insects.
They probably also feed on vegetable matter, since Woodroffe (1966) was partly
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