Megarcys ochracea Klapálek, 1912

Judson, Sarah W. & Nelson, C. Riley, 2012, 3541, Zootaxa 3541, pp. 1-118 : 44

Megarcys ochracea Klapálek, 1912

SYNONYMY

Perlodes (Megarcys) ochracea Klapálek, 1912

Megarcys ochracea Kasai, 1938

Arcynopteryx (Megarcys) ochracea Ricker, 1952

Megarcys ochracea Illies, 1966

TYPE LOCALITY: USSR: Sachalin, Hokkadate .

DIAGNOSIS: Adults retain the remnants of nymphal thoracic ( Fig. 233) and submental gills ( Fig. 244). The male hemitergal processes are strongly curved ( Fig. 279) and point anteriorly. The epiproct of the male has lateral stylets which extend slightly over the hemitergal processes. The female subgenital plate has a narrow median notch guarded by two medially directed, subtriangular lobes ( Fig. 280). Nymphal head pattern ( Fig. 281) includes a distinct M-line on the clypeus and white patches posterior to the eyes and in the interocellar region, all coloration characters of which are shared with A. compacta nymphs. Despite these superficial similarities, Megarcys and Arcynopteryx nymphs can be easily separated with genus-level characteristics, particularly the presence of gills. The nymph of Megarcys has finger-like thoracic gills ( Fig. 233) in addition to submental gills ( Fig. 244).

DISTRIBUTION—Global: East Palearctic— Regional: AOB, IDB^— Aimag: BU^, KhG^, SE, TO.

DISCUSSION: Most of the M. ochracea documented by our survey were from mid-range elevations (approx. 800–1500 msl) and has only been documented in the Selenge River basin, especially near Lake Khovsgol ( Fig. 282). The species was first recorded from Mongolia by Zhiltzova (1972) .