Isoperla mongolica Zhiltzova, 1972

Judson, Sarah W. & Nelson, C. Riley, 2012, 3541, Zootaxa 3541, pp. 1-118 : 48-49

Isoperla mongolica Zhiltzova, 1972

SYNONYMY

Isoperla mongolica Zhiltzova, 1972

TYPE LOCALITY: Mongolia: Tula River near Ulan Bator .

DIAGNOSIS: Adult head generally infuscate ( Fig. 336), with a pale, central, anteriorly-pointed oval between the ocelli, most closely resembling I. potanini which is darker overall color ( Fig. 345). The paraprocts of the male are stout, heavily sclerotized and dark, and curved over the 10th tergum ( Fig. 338). The underside of the paraproct tips are populated with small spines which are most evident in lateral view ( Fig. 338). The female subgenital plate is broad and barely extends over the posterior margin of sternum 8 ( Fig. 338). The plate is similar to that of I. potanini and I. asiatica ( Fig. 319) though I. potanini has a shallow medial notch ( Fig. 348) and I. asiatica can be distinguished on the basis of head coloration ( Fig. 316). The head of the nymphs is dark overall and is punctuated by four pale spots arranged longitudinally along the median ( Fig. 307). The nymph is distinct from the otherwise similarly colored I. obscura based on abdominal coloration, specifically the placement of pale heart shaped marks of which I. mongolica has only one on the terminal abdominal segment.

DISTRIBUTION—Global: East Palearctic— Regional: AOB, IDB^, POB*— Aimag: AR, BO, KhD, KhE*, KhG, TO^, UB*, ZA.

DISCUSSION: As the name suggests, this species was originally described from Mongolia by Zhiltzova (1972) in her first contribution to the Insects of Mongolia series in which I. kozlovi was also described. Isoperla mongolica was most commonly collected from high (>1700 msl) elevation streams, but was also occasionally found at lower elevations with a few collections near the type locality in central Mongolia.