|scientific name Chlaenius alternatus |
Have been collected on the borders of slow rivers with firm soil and vegetation consisting of Carex, Juncus, and Equisetum fluviatile. Others have been collected on lake shores among thick vegetation consisting of Naumburgia thyrsiflora, Triglochin palustre, Cicuta, Mentha, Carices, and a moss undercover of Drepanocladius aduncus.
Larvae have been collected in early August. Adults have been collected in Alberta from mid-May to mid-July.
Adults: 10.5-14mm in length. Dorsal surface black and metallic though this can sometimes be faint. Pronotom often with a brassy or greenish hue laterally. Appendages black. Can be easily distinguished from all other Alberta species because all striae are broken at several points along their length; intervals are connected by convexities giving the elytral surface a transversely corrugated appearance; intervals 3, 5, 7, usually more convex. Setae behind pronotal shoulder are unicolorous, pale brown. Adapted from Bell 1960 and Lindroth 1963
Bell (1960) suggests that there is evidence that alternatus ranged far south of it's current distribution during the Ice Age as a species (C. plicatipannis) that is identical or closely related has been described from the Sangamon Peat of central Illinois.
The most boreal species of all North American Chlaenius. Known from scattered records across Canada and far south as the Montana. Has been recorded in Alberta from the Cypress Hills to as far north as Athabasca.
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