NEEDLE IN A HAYSTACK: HUNTING FOR A RARE DRAGONFLY (RHIONAESCHNA MUTATA) IN THE ST. CROIX RIVER VALLEY, MN
The Spatterdock Darner, Rhionaeschna mutata , is a rare North American dragonfly, which is most widely distributed in the eastern USA. In 2009, a breeding population was found in two kettle ponds in the Saint Croix River Valley in eastern Minnesota. This was the first record of this species in Minnesota, establishing a substantial northwestern range expansion. The goal of our research was to characterize R. mutata breeding habitat and geographic distribution in Minnesota to inform conservation planning. We compiled information on R. mutata habitat preferences, and then selected 25 potential breeding sites, targeting heavily vegetated, fishless ponds with a sphagnum fringe and a wooded riparian zone. We conducted early summer field surveys in 2015 and 2016, using multiple methods to increase our likelihood of detection (visual adult surveys; shoreline exuviae collections; aquatic nymph sampling with dip-nets, minnow seines, and sweep frames). No R. mutata were found. R. mutata may be present in this water-rich region, but has gone undetected by our efforts, or a local extirpation may have occurred, possibly linked recent fish colonization in one of the original breeding ponds.
Emily Schilling (Primary Presenter/Author, Co-Presenter/Co-Author), Augsburg University, firstname.lastname@example.org;
Holly Kundel ( Co-Presenter/Co-Author), Augsburg University, email@example.com;
Ron Lawrenz ( Co-Presenter/Co-Author), Warner Nature Center - Science Museum of Minnesota, firstname.lastname@example.org;