Nemoura cinerea (Retzius, 1783)

Judson, Sarah W. & Nelson, C. Riley, 2012, 3541, Zootaxa 3541, pp. 1-118 : 33-34

Nemoura cinerea (Retzius, 1783)

SYNONYMY

Perla cinerea Retzius, 1783

Nemura cinerea Illies, 1955

TYPE LOCALITY: Sweden .

DIAGNOSIS: This species is characterized by the epiproct having apical prongs of the ventral sclerite that are triangular, and come to a point which has a few spines at the apex ( Fig. 177, 178). In contrast, N. sahlbergi has prongs which are more rounded and have more spines at the apex( Fig. 187). Like, N. arctica ( Fig. 174), the outer (major) lobe of the paraproct of N. cinerea is convex ( Fig. 179), but in N. cinerea the narrow dividing notch at the apex of the segment creates an asymmetrical structure with an outline in the shape of a mitten ( Fig. 179). Cerci of this species have only 2 apical spines perpendicular to the cercus. Unlike other Nemoura , the cerci are twisted in such a way that the black dot in the center of the membranous portion is readily visible ventrally ( Fig. 179), rather than dorsally ( Fig. 186). The female subgenital plate has a broad central bump, but this is not particularly diagnostic because of variability within the species. Nemoura cinerea is noted to have rather homogenous hair across the femora with some longer hairs dorsally near the distal margin. However, this character is variably distinguishable from N. arctica and N. sahlbergi , such that Lillehammer (1988) included N. cinerea in two portions of his key both with and without this type of setation. Nemoura cinerea nymphs lack hairs on the galea, which N. arctica and N. sahlbergi possess.

DISTRIBUTION—Global: Trans-Palearctic— Regional: AOB, IDB*— Aimag: AR^, BU^, KhD*, KhG^, SE*, TO^, ZA^.

DISCUSSION: Nemoura cinerea appears to be restricted to the Selenge River Basin ( Fig. 180) and was also recently documented in this region by Teslenko and Bazova (2009). The synonymic history of N. cinerea is very long and primarily deals with European species, much of which is not relevant to Mongolia. For a full history of this species, please refer to DeWalt et al. (2010).