Beetles Identification Guide

Sexual dimorphism: Males usually have the last exposed abdominal tergum uniformly
brown (Stemly and Wilbur 1966) and a shallow groove, entire or somewhat
broken, on each side of the fifth visible abdominal sternum (Ghorpade and
Thyagarajan 1980); occasionally, the groove may be missing on one side of the
sternum. In females the last exposed tergum is usually pale yellow and the fifth
visible abdominal sternum more convex laterally and without a groove. Sinclair
(1981) discussed the reliability of both characters.
Distribution: Throughout the warm regions of the world, mainly confined to
heated buildings in the temperate regions. In Canada the species has been reported
in Quebec, Ontario, Manitoba, Saskatchewan, and British Columbia.
Economic importance: This species is well known as a pest of stored grain in all
warm regions of the world. It also occurs on a wide variety of food, particularly
cereals. The damage is done by both adults and larvae. Rhyzopertha dominica is
not a serious pest in Canada, even though it is intercepted regularly at ports in
imported grain and is found occasionally in food-processing plants and mills, where
it can survive for some time. The species may eventually become established in
this country; Storey et al. (1983) reported that its distribution in the United
States has expanded in recent decades throughout the grain-producing areas to
include even the northernmost states bordering Canada.
Selected references
Howe, R.W. 1950. The development of Rhizopertha dominica (F.) (Col.,
Bostrichidae) under constant conditions. Entomol. Mon. Mag. 86:1—5.
Kingsolver, J.M. 1971. A key to the genera and species of Bostrichidae commonly
intercepted in USDA Plant Quarantine Inspection. U.S. Department of
Agriculture, Agricultural Quarantine Inspection Memorandum, No. 697.
11 pp.
Potter, C. 1935. The biology and distribution of Rhizopertha dominica (Fab.).
Trans. R. Entomol. Soc. Lond. 83:449—482.
Spilman, T.J. 1982. False powderpost beetles of the genus Dinoderus in North
America (Coleoptera, Bostrichidae). Coleopt. Bull. 36:193—196.
BRUCHIDAE seed beetles
In Canada the bruchids are represented by about 20 species. The adults are
found on flowers and foliage. The larvae eat the seeds of various plants, mainly
Leguminosae. Since they feed inside the seed, infestations are usually not apparent
until the adults emerge.
Most species of this family are field pests, infesting ripening pods or the
exposed seeds of growing plants. Adults of some of these species may emerge
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