Beetles Identification Guide

Economic importance: This species is one of the most common household pests
in Canada, found more frequently in apartments and other multiple dwellings
than in houses. Loschiavo and Sabourin (1982) estimated that the total cost of
infestation in Canadian residences reached $6 million in 1980. Both adults and
larvae feed mainly on cereal products, particularly those with high oil content
such as oatmeal, bran, shelled sunflower seeds, rolled oats, and brown rice
(Loschiavo and Smith 1970; Loschiavo 1976). Unlike O. surinamensis, O. mercator
has not been reported as a pest of stored grain in Canada.
Oryzaephilus surinamensis (Linnaeus)
sawtoothed grain beetle
cucujide dentelé des grains
Diagnosis: The species differs from O. mercator in having the temple proportionally
longer, its length being equal to or more than half the vertical diameter
of the eye.
Sexual dimorphism: As in O. mercator, males have the posterior margin of the
hind trochanter and the upper margin of the hind femur medially with a spinelike
projection; females lack such projection on the hind trochanter and femur
(Fig. 245).
Distribution: Cosmopolitan. The species is found across Canada in the temperate
regions. Unlike O. mercator, it can survive Canadian winter conditions in
unheated premises.
Economic importance: In Canada this species is a serious pest of stored grain
and occurs primarily in granaries, grain elevators, and flour mills. Both adults and
larvae attack damaged grain and processed cereals. Its presence in household
products is incidental and causes little concern (Loschiavo and Sabourin 1982).
Selected References
Ashby, K.R. 1961. The life history and reproductive potential of Cryptolestes
pusillus (Schönherr) (Col. Cucujidae) at high temperatures and humidity.
Bull. Entomol. Res. 52:353–361.
Banks, H.J. 1979. Identification of stored product Cryptolestes spp. (Coleoptera:
Cucujidae): A rapid technique for preparation of suitable mounts. J. Aust.
Entomol. Soc. 18:217—222.
Bishop, G.W. 1959. The comparative bionomics of American Cryptolestes
(Coleoptera-Cucujidae) that infest stored grain. Ann. Entomol. Soc. Am.
52:657—665.
Curtis, C.E.; Clark, J.D. 1974. Comparative biologies of Oryzaephilus
surinamensis and mercator (Coleoptera: Cucujidae) on dried fruits and nuts.
U.S. Dep. Agric. Tech. Bull. 1488. 42 pp.
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