Beetles Identification Guide

Distribution: Japan and introduced in North America since 1921 and in England
since about 1940. In Canada the species has been reported in New Brunswick,
Quebec, Ontario, Alberta, and British Columbia.
Economic importance: As far as is known, all specimens collected in Canada
have been found in warehouses. Pellitteri and Boush (1983) reported the species
in feed mills in southern Wisconsin.
Ptinus bicinctus Sturm
Diagnosis: The species is superficially similar to P. fur but differs in having the
setae on the disc of the pronotum more or less evenly distributed, not forming
distinct tufts.
Sexual dimorphism: Males (as in Fig. 224) have the elytra subparallel-sided, the
eyes larger and more convex, the antennae longer (10th segment about five times
as long as wide), and the metasternum longer, feebly convex, and with a median
longitudinal line. Females (as in Fig. 225) have the elytra subobovate, the eyes
smaller and less convex, the antennae shorter (10th segment about twice as long
as wide), and the metasternum shorter, more convex, and without a median line.
Distribution: Europe, North Africa, and introduced in North America. In
Canada P. bicinctus has been found in Nova Scotia, New Brunswick, Quebec,
Ontario, Alberta, and British Columbia.
Economic importance: In this country the species is occasionally reported in
warehouses and dwellings.
Ptinus clavipes Panzer (synonym: P. hirtellus Sturm)
brown spider beetle
ptine brun
Diagnosis: The species is separated from the other Ptinus dealt with here, except
P. ocellus, by its elytra devoid of white scales. It differs from P. ocellus in having
the elytral surface not obscured by the vestiture.
Females of this species exist in two forms, a diploid sexual form and a triploid
parthenogenetic form. Both were believed to represent separate species,
under the name P. hirtellus Sturm and P. latro Boieldieu respectively, until Moore
et al. (1956) demonstrated that there is only a single species. The diploid form
differs from the triploid form in having the elytra less elongate, the setae on the
pronotum and elytra less coarse, the setae on the elytral intervals slightly unequal
in size, and the humeral region with a patch of appressed pale yellow setae.
Sexual dimorphism: Males (as in Fig. 224) have the elytra subparallel-sided, the
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