NEW RECORDS OF WINTER STONEFLIES (PLECOPTERA) FROM MANITOBA WITH NOTES ON THEIR ZOOGEOGRAPHICAL ORIGINS

Abstract

AbstractRecent collections (1980–1982) of winter stoneflies in southern Manitoba have resulted in the addition of five previously unrecorded species: Capnia coloradensis Claassen, C. confusa Claassen, Paracapnia angulata Hanson, Skwala parallela (Frison), and Utacapnia trava (Nebeker and Gaufin) to the nine previously recorded species. Eight of the 14 species now known from Manitoba occur in the small spring-fed streams on the east escarpment of the Duck Mountain Provincial Park. The probable zoogeographical origins and present distribution of winter stoneflies in Manitoba are explained in light of various post-glacial drainage patterns. Adults of U. trava were observed, often copulating, on the underside of the ice. They were also observed crawling away from streams with no ice cover to a distance of 50 m.