Neurocordulia yamaskanensis (Provancher, 1875)
Stygian Shadowdragon
NatureServe Global Rank: G5
Virginia State Rank: S2
VA DGIF Tier: IV
Federal Legal Status: None
Virginia Legal Status: None
Description: The Stygian Shadowdragon is an entirely light-brown dragonfly, including the eyes. The wings are clear with a dark or amber patch at the wing base, larger on the hindwing. The thorax is grayish on the sides and darker above, with a white line down the middle. The size ranges from 45-55 mm (1.8 - 2 .2 inches).
Similar species: Other shadowdragon species in Virginia, such as the Umber Shadowdragon (N. obsoleta), have small amber spots along the leading edge of the wings. The white line down the center top of the thorax is also distinctive. Due to their crepuscular flight, shadowdragon species are very difficult to identify on the wing, so catching and releasing is likely necessary.
North American Range: Stygian Shadowdragons are Northeastern in distribution, from Maine and southern Ontario south through the Appalachians to Kentucky and Tennessee. In Virginia, they are found in higher elevation western counties.
VA Observations by Locality: Scott | Alleghany | Floyd | Giles | Grayson | Radford, City of | Shenandoah | Grayson | Scott
Flight season and broods: Adult Stygian Shadowdragon have been recorded from 7 May - 28 June in Virginia.
Aquatic Habitat: Stygian Shadowdragon prefer medium to large mountain rivers.
Behavior and Ecology: Shadowdragons fly very fast only in the late evening low over the water surface, so are rarely noticed except by deliberate effort. Occasionally they are found roosting in vegetation near their river habitat.
Population trend and potential threats: It is regarded as imperiled in many states throughout its range (NatureServe, 2011), though the difficulty of observing the species may obscure its actual occurrence.
Management practices: Monitor and preserve occupied habitats.
References: Carle, F.L., 1982. A contribution to the knowledge of the Odonata. Ph.D. thesis, Virginia Polytechnic Institute and State University, Blacksburg, Virginia. 1,095 pp.
NatureServe. 2011. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://www.natureserve.org/explorer (Accessed: Nov. 8, 2012).
Paulson, Dennis. 2011. Dragonflies and Damselflies of the East. Princeton University Press. Princeton and Oxford. 538 pp.
Roble, Steven M. 2011. Dragonflies of Virginia- Flight dates. Unpub.