New York Natural Heritage Program
Broad-tailed Shadowdragon
Neurocordulia michaeli Brunelle, 2000
Insects

General Description [-]
The thorax is brown, the abdomen is blackish with bold yellow rectangles on the sides. The wings are suffused with an orangish tinge at the base, and the eyes are dull greenish to yellowish.

Identifying Characteristics [-]
Larvae and exuviae are very similar to the Stygian Shadowdragon and capture of adults is necessary to document new sites.

Characters Most Useful for Identification [-]
The body and wing coloration is very reminiscent of a Baskettail (Paulson, 2011), but the lotic (flowing water) habitat and crepuscular activity period should serve to distinguish a Shadowdragon from the more ubiquitous, usually lentic (stagnant water) Baskettails.

Best Life Stage for Proper Identification [-]
Adults are very elusive and crepuscular, but offer definitive identification of this species.

Behavior [-]
As with all Neurocordulia, this is a crepuscular (twilight) species that flies for about 45 minutes after sundown in late May to early June in New York. Daylight hours are probably spent at rest in the understory of surrounding forests (Catling et al., 2004). Eggs are laid in rapids and the downstream ends of pools, and development of larvae occurs in the interstices of the benthic cobbles.

Diet [-]
The larvae are generalist predators, while the adults feed on emerging mayflies.
Broad-tailed Shadowdragon Images
click to enlarge
The Best Time to See
In New York, this species has only been detected during the last few days in May and first couple days of June. In Ontario and Maine, the flight season encompasses June, July.
J F M A M J J A S O N D
Reproducing Larvae present and active
The time of year you would expect to find Broad-tailed Shadowdragon reproducing (blue shading) and larvae present and active (orange shading) in New York.
Similar Species
  • Stygian Shadowdragon (Neurocordulia yamaskanensis)
    The legs of this species are lighter, and the basal wing spot is darker than the Broad-tailed. The larvae of this species is nearly identical to N. michaeli, and usually only discernible by experts.
  • Umber Shadowdragon (Neurocordulia obsoleta)
    The legs of this species are lighter, and the basal wing spot is darker than the Broad-tailed. The larvae are very similar, but the dorsal hooks are erect (not blunt) in N. obsoleta.