SeasonalityAdults collected in Alberta from mid-May to early August, but seem to be most active in June.
IdentificationAdults: 11.3-14.8mm in length. Entire dorsal surface black. Head and pronotum without hints of violet sometimes seen in C. purpuricollis frosti. Appendages black or piceous. Pronotum very distinct, transverse with widest point being slightly posterior to middle, sides almost evenly curved (C. purpuricollis frosti has sides that are much wider at base); basal margin almost straight; lateral rim very prominent in comparison to other Alberta species. In this species, pronotal punctures are quite large and shallow with very short pubescence, leaving only patches of disc smooth; basal fovea broad, irregular, not reaching centre of prothorax. Prosternum with sparse, course, shallow punctures. Microsculpture isodiametric, readily seen on pronotom and elytra. Intervals slightly convex and densely punctate; setae reddish. Adapted from Bell 1960 and Lindroth 1963.