Beetles Identification Guide

or 2 facets). It is most similar to T. castaneum but differs from it in having the
antenna with 5- or 6-segmented club and the eye only 1 or 2 facets wide laterally.
Sexual dimorphism: Males have a setiferous fovea on the posterior side of all
femora. Females have no such setiferous fovea.
Distribution: Cosmopolitan. In Canada this species occurs from coast to coast.
Economic importance: This species is probably the most serious pest of the genus
Tribolium and one of the most economically important beetles. It is notorious
as a pest of cereal products, although the adults and larvae also feed on a
wide variety of foodstuffs including sound grain. In Canada this beetle is found
most frequently in flour mills and feed mills. It also occurs in warehouses, grocery
stores, and dwellings. According to Sokoloff and Lerner (1967), when both
T. confusum and T. castaneum occur in the same surroundings, they can coexist
but only at a low population density. In mixed laboratory cultures, however, one
of the two species is eliminated; the type of food and the temperature influence
which of the two species survives.
Tribolium destructor Uyttenboogaart
large flour beetle
tribolium de la farine
Diagnosis: The species is best recognized among the Tribolium dealt with here
by its relatively large size, which exceeds 4.5 mm, and the narrow eyes laterally
(width of 1 or 2 facets).
Sexual dimorphism: Males have a setiferous area on the posterior side of the fore
femur. Females have no such setiferous area.
Distribution: Known in Africa, where it probably originated, Asia, Europe, and
North America. In Canada the species occurs from coast to coast.
Economic importance: This species is a pest of seeds, cereals, and their products.
In Canada it usually occurs in flour and cereal products found mainly in flour
mills, bakeries, and dwellings. Locally in Alberta, the species can be as economically
important as other serious pests, such as T. confusum and T. castaneum (L.B.
Smith, personal communication).
Tribolium madens (Charpentier)
black flour beetle
Diagnosis: This species is closely related to T. audax, and both were confused
under the name T. madens until recently (Halstead 1969). This species differs
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