Beetles Identification Guide

Economic importance: Smith and Barker (1987) recently have found the species
to be quite common in granaries throughout the Prairie Provinces.
Trogoderma sternale Jayne
Diagnosis: The species somewhat resembles T. variabile but differs mainly in
having the basal and submedian bands of each elytron connected by a longitudinal
band or bands and the male antennal club serrate.
This species is closely related to T. ornatum (Say), which in Canada occurs
only in southern Ontario. Adults of the two species differ externally mainly in
the size of the male third antennal segment. In T. sternale the segment is minute
and about half the length and width of the second or fourth segment (Fig. 88); in
T. ornatum, the segment is larger and about the same length and width as the
second or fourth segment. In addition, the male antennae are more serrate in T.
ornatum than in T. sternale. Trogoderma ornatum has not yet been reported as a
pest in Canada but has been found in a wide variety of products and is known to
infest dried insect collections in the United States.
Sexual dimorphism: Males have a 6- or 7-segmented antennal club, females a 4segmented
one (Fig. 251).
Distribution: Exclusively North American. In Canada the species has been reported
only from British Columbia.
Economic importance: The species is a minor pest. It has been recorded in animal
and vegetable materials and is known to attack dried insect collections. It
also occurs in granaries, where it probably survives on dead insects.
Trogoderma variabile Ballion (synonym: T. parabile Beal)
warehouse beetle
trogoderme des entrepôts
Diagnosis: The medial margin of the eye entire, with the bicolorous elytral integument
distinguish this species from the other Trogoderma dealt with here,
except T. sternale. It differs from T. sternale, however, in having the basal and
submedian bands of each elytron free, not connected by a longitudinal band or
bands, and the male antennal club not serrate.
Sexual dimorphism: Males have a 6- or 7-segmented antennal club, females a 4segmented
one (Fig. 252).
Distribution: Holarctic and found in Europe, Asia, and North America. In
Canada the species ranges from New Brunswick west to British Columbia.
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