Aquatic Insects of Michigan
by Ethan Bright, Museum of Zoology Insect Division and School of Natural Resources and Environment
Basiaeschna Selys, 1833 - Springtime Darner
A montypic genus, Basiaeschna janata Say, 1839 ranges over a wide range in North America and is encountered throughout Michigan.
Adults are rather small, brownish aeshnids, the sides of the thorax conspicously adorned with parallel yellow stripes and blackish spots at the base of the wings. They are active fliers close to the surface of the water along riffles of streams and wooded lake shores. Nymphs of Basiaeschna janata are similar in appearance and habits to Boyeria but are differentiated by longer paraprocts, pointed palpal lobes, and earlier adult emergence. Walker's (1958) description of this species' habitat preferences appears well-supported by their collection in Michigan. They are frequently collected on the undersides of stones and water-logged woody material in slower-moving parts of forest stream riffles, but are more frequently collected in sheltered parts of well-oxygenated lakes. For emergence (mid-May through mid-June), nymphs climb on vegetation, stumps and man-made objects almost 2 m in height in order to emerge. Collection of nymphs in Marquette County appear to indicate two size classes, suggesting a two-year developmental period before adult emergence (EB, pers. obs.).
Taxonomic references (Needham et al. 2014, Paulson 2011, Walker 1958)
Paulson D. 2011. Dragonflies and damselflies of the East. Princeton Field Guides. Princeton University Press, Pinceton, New Jersey, USA. 538 p.
Say T. 1839. Descriptions of new North American neuropterous insects and observations on some already described by (the late) Th. Say. Journal of the Academy of Natural Science of Philadelphia 8:9-46.
Selys-Longchamps ME de. 1883. Synopsis des Aeschnines. Première partie: Classification. Bulletin de l'Académie royale des Sciences de Belgique 3(5): 712-748.
Walker EM. 1958. The Odonata of Canada and Alaska, Vol. 2. University of Toronto Press: Toronto. xii + 318.
Page last edited: February 28, 2017 (EB)