Description and Taxonomy

Length 9.5-11mm. This medium sized Nebria species is superficially similar to N. pallipes but can be easily distinguished from it by the uniformly dark head lacking rufous spots on the frons and the pronotum possessing midlateral setae (Kavanaugh 1979). Also, the species possesses a strongly cordate pronotum that are obviously sinuate before the hind-angles, and has the elytral apex obvious emarginate at the suture (Lindroth 1961). In the Nearctic Region, the genus is represented by 53 species, three of them occuring in the Smokies (Ball and Bousquet 2001).

Life History

The species is strongly hygrophilous and confined to stony margins of running water. In GSMNP adults prefer streams in shaded areas from middle altitudes (500m) and up. In general, with increasing altitude the species replaces N. pallipes and in turn is replaced at high altitudes by N. appalachia, which inhabits the uppermost reaches of streams. Specimens from GSMNP were collected during late May-September. At Little River the species was taken at the same locality as N. pallipes, but not together.

Distribution

The species is widely distributed through northeastern North America as far south as Tennessee and North Carolina and north to Quebec and Ontario (Bousquet and Larochelle 1993). The subspecies is a Great Smoky Mountains endemic and was described from GSMNP (Kavanaugh 1979, map, type locality indicated by red triangle).  At present Louisiana State Arthropod Museum posesses specimens from scattered localities in GSMNP, but material studied by Kavanaugh (1979) suggested that the subspecies is widely distributed and inhabits most streams inside GSMNP.

Conservation Concerns

Not under threat.