Beetles Identification Guide

Most species feed almost exclusively on materials of animal origin such as
bones, skins, fur, wool, and silk. Some species, however, can subsist partly or
wholly on vegetable matter, and a few, such as Trogoderma granarium, feed
exclusively on vegetable material.
About half the dermestid species occurring in Canada are household and
museum pests or are associated with stored products. Many of these species,
however, are not serious pests. In some groups, such as Dermestes and Thylodrias,
both adults and larvae are harmful to human commodities, although the damage
caused by the larvae is more important. In other genera, such as Anthrenus,
Attagenus, and Trogoderma, only the larvae are economically important, since the
adults do not feed or, if they do, feed outdoors on pollen and nectar.
Anthrenus fuscus Olivier
Diagnosis: The species is readily separated from the other Anthrenus dealt with
here in having the antenna 5-segmented with a l-segmented club.
Sexual dimorphism: Males have the last antennal segment proportionally longer
(at least five times as long as the 2 preceding segments combined) (Fig. 248) and
the antennal cavity of the prothorax also proportionally longer (occupying about
two-thirds of the lateral margin). In females the last antennal segment is three
to four times as long as the 2 preceding segments combined (Fig. 248), and the
antennal cavity occupies about half of the lateral margin of the prothorax.
Distribution: Europe and introduced in eastern North America. In Canada the
species is known in southern Quebec and southern Ontario.
Economic importance: This species is a minor pest in North America. It has
been found in flour mills, warehouses, and houses, where the larvae probably survive
on the remains of insects. In Europe A. fuscus has been recorded damaging
dried insect collections; it also occurs in bird nests, aculeate Hymenoptera nests,
and in and around spider webs.
Anthrenus museorum (Linnaeus)
museum beetle
Diagnosis: The species is distinctive among the Anthrenus included here in having
the antenna 8-segmented with a 2-segmented club.
Externally, this species is similar to A. castaneae Melsheimer, and it is possible
that earlier records of A. museorum refer to A. castaneae. Adults of A. castaneae
differ in having the last antennal segment proportionally shorter, 2—3 times as
long as the preceding segment in the male and 1.4—2.2 in the female. In A.
museorum the last antennal segment is at least five times as long as the preceding
segment in the male and 2.1—2.8 in the female (Hoebeke et al. 1985). Anthrenus
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