Odonata of Coastal Peatland Habitats Adjacent to Lake Superior in Wisconsin

We sampled adults and exuviae of Odonata in eleven coastal fens and poor fens near Lake Superior in Douglas, Bayfield, and Ashland counties in Wisconsin to determine species that were breeding in these areas, and gain knowledge about their relative abundances, flight periods, and nymphal habitats. The flora in these fens was characterized by mats of Sphagnum mosses, a variety of ericaceous shrubs, and a number of sedges, among which Carex lasiocarpa Ehrhart (slender sedge) was most dominant. We averaged seven visits per site from early June through September, 2004, to cover the flight periods of most species of Odonata at this latitude. Fifty species of Odonata were identified at the sites, 33 of which exhibited evidence of breeding. Species commonly breeding in the fens included Lestes disjunctus Selys (northern spreadwing), Coenagrion resolutum (Hagen in Selys) (taiga bluet), Enallagma hageni (Walsh) (Hagen’s bluet), Nehalennia irene (Hagen) (sedge sprite), Aeshna canadensis Walker (Canada darner), Williamsonia fletcheri Williamson (ebony boghaunter), Leucorrhinia frigida Hagen (frosted whiteface), L. glacialis Hagen (crimson-ringed whiteface), L. hudsonica (Selys) (Hudsonian whiteface), Libellula quadrimaculata Linnaeus (four-spotted skimmer), Sympetrum obtrusum (Hagen) (white-faced meadowhawk), and S. vicinum (Hagen) (autumn meadowhawk). Eight uncommon species were found to breed in at least one of the fens, including Lestes eurinus Say (amber-winged spreadwing), Aeshna sitchensis Hagen (zigzag darner), A. tuberculifera Walker (black-tipped darner), A. verticalis Hagen (green-striped darner), Somatochlora incurvata Walker (incurvate emerald), W. fletcheri, Nannothemis bella (Uhler) (elfin skimmer), and Sympetrum danae (Sulzer) (black meadowhawk). W. fletcheri and S. danae were found to be more common in these habitats than previously thought, causing their rarity status with the Natural Heritage Inventory of the Wisconsin Department of Natural Resources to be relaxed, and they will no longer be actively tracked. Emergence and flight periods of Odonata in coastal peatlands began at least a week later than in similar inland peatlands in these counties.