Fig. 1: Exuvia of E. heros, scanned by M. O'Brien
A monotypic genus, E. heros (Figure 1, above) is one of the largest of North America's dragonflies. These large brown larvae are encountered in ponds and lakes, often with much aquatic vegetation. Walker (1958) found nymphs in a shaded pond a few yards inside a wood lot in Ontario, whereas Williamson (1903) collected larvae in Tennessee from ditches and marshes associated with chimney-building crayfish. Morphologically similar to Nasiaeschna in regards to the mid-dorsal abdominal ridge, but differs from that monotypic genus in that the abdominal segments of E. heros lack mid-dorsal hooks. Adults emerge from June through early July, and may fly in large swarms. Records of this species are known only from the LP (Map 1), although adults - which are strong flyers - probably also occur in the UP.
Fabricius, J. C. 1798. Supplementum entomologiae systematicae, pp. 283-285. Proft. (Schubothe), Hafniae.
Hagen, H. A. 1877. Synopsis of the Odonata of America. Proceedings of the Boston Society of Natural History 18:86.
Walker, E. M. 1958. The Odonata of Canada and Alaska, Vol. 2. University of Toronto Press: Toronto. xii + 318.
Williamson, E. B. 1903. The dragonflies (Odonata) of Tennessee, with a few records for Virginia and Alabama. Entomological News 14:221-229.