Nemoura lepnevae Zhiltzova, 1971

Teslenko, Valentina A. & Palatov, Dmitry M., 2021, A poorly known species and new records of Plecoptera from the Eastern Tien Shan, Xinjiang Uygur Autonomous Region, China, Zootaxa 4950 (1), pp. 123-136 : 125-127

Nemoura lepnevae Zhiltzova, 1971

Figs. 6–7

Zhiltzova, 1971:358, figs. 25–28; Grizay, Zhitzova, 1973:25; Zwick, 1973:338; Zhiltzova, 1984:714; Zhiltzova, 2003:284, figs. 470–472; Teslenko, Zhiltzova, 2009: 158, figs. 925–927.

Material examined. China, the Xinjiang Uygur Autonomous Region, Eastern Tien Shan : 1 male, 1 female, 1 nymph, Bogdo-Ula Range, Urumqi city, Dabancheng District , Sangecha Stream , 35 km N of Dabancheng, an altitude 2,356 m above sea level, 13.VII.2017, N 43°40.583’, E 88°17.006’, leg. D.M. P .; 2 males, Karlyktag Range, Hami city, Ayar-Gol Stream , 60 km NE of Hami, an altitude 2,426 m above sea level, 21.VII.2017, N 43°12.225’, E 94°07.128’, leg. D.M. P .

Supplementary description. Male. Epiproct oval ( Fig. 6 ), distally elongate, rapidly narrowing to the narrow apex, and slightly constricted in distal third ( Fig. 7 ). Basal sclerites are triangular. Lateral arms of dorsal sclerite finger-like, half-rounded with a truncated tip, directed obliquely toward middle and slightly sclerotized, whereas the pair of dorsal folds are shallow and covered with comb-like scales that are larger laterally ( Figs. 6, 7 ). Ventral sclerite lanceolate at the base, bearing three to four pairs of strong ventral spines. Ventral sclerite apically developed into a pair of long, heavy sclerotized straps extending upwards and laterally. In the dorsal view, the ventral sclerite appears as a pair of oval and oblique prolonged sclerites (resembling a Peter Pan collar) or moveable prongs forming a ring, interrupted dorsomedially, directed downward that is visible through the lateral folds of the dorsal sclerite ( Fig. 8 ). Outer angles of ring rectangular and rounded ( Figs. 7, 8 ).

There are moveable prongs or a ring surrounding the apical sclerite and an arrow-shaped membranous projection of the ventral sclerite, extending forward ( Figs. 7, 8 ). Each apical sclerite is elongated anteriorly, with membranous folds contacting along the inner edge. The base extends beyond the dorsal folds of dorsal sclerite with paired triangular lobes at the basolateral edges ( Figs. 7, 8 ). Each lobe is delicately sclerotized and bears a few small spines directed outward at the corner.

Female. The pregenital plate has a shallowly rounded posterior margin ( Fig. 9 ). In cleared slide-mounted genitalia, the subgenital plate of sternum 8 bears a dark, funnel-shaped sclerite ( Figs. 9, 10 ). Paragenital plate lobes are difficult to distinguish, being hidden beneath the pregenital plate ( Fig. 9 ). The vaginal pouch shell-shaped, the posterior edge concave, and the anterior edge is straight ( Figs. 9, 10 ). The pouch connects with the oviduct in the middle of the anterior edge. Inside the pouch there is a darker sclerite anteriorly and a pair of round, roughened pockets that occupy the posterior half of the pouch ( Fig. 10 ). At least three transverse prolonged folds are visible laterally ( Fig. 10 ).

Note. The Uygur specimens of N. lepnevae agree well with the original description and detailed illustrations of the external genital structures ( Zhiltzova 1971, 2003). There are differences in the shapes of some of the epiproct sclerites, especially the apical sclerites. The apical sclerites basally bear paired triangular lobes that appear when the specimen is mounted ( Figs. 7, 8 ); at rest triangular lobes are folded and touch each other; therefore, the basal part of the apical sclerite has a smooth outer edge (as Zhiltzova 2003, fig. 472).

Distribution and ecology. Nemoura lepnevae was originally described from a stream on the north slope of Dolon Pass (altitude of 3,030 m above sea level) located between the Songköl Too and Bayduluu Ranges in Central Tien Shan, Naryn Region, Kyrgyzstan ( Zhiltzova 1971). The Naryn Region borders Xinjiang Uygur Autonomous Region of China in the southeast. Records of N. lepnevae in the streams in Bogdo-Ula and Karlyktag Ranges significantly expand our understanding of the distribution of this species to the east. This abundant and widespread species inhabits mountain streams of the western, central, and northern Tien Shan Ranges and Pamir Mountains at altitudes of 800 to 3,300 m and has an extended period of emergence from June to August ( Zhiltzova 2003). This is the first report of N. lepnevae in Eastern Tien Shan and the stonefly fauna of China. Specimens were collected along with F. wusuensis and M. pecirkai in the forest Sangecha stream with boulders at the bottom, and in the Ayar-Gol stream, whose bank is covered with coniferous trees at an altitude of 2,356 –2,426 m above sea level ( Figs. 35, 37 ).

Figures

FIGURES 6–10. Nemoura lepnevae, cleared. 6. Abdominal tip, male, ventral. 7. Epiproct, dorsal. 8. Epiproct, ventral. 9. Female subgenital plate, ventral. 10. Female vaginal complex.

FIGURES 33–37. Сollecting places in the Xinjiang Uygur Autonomous Region, the Eastern Tien Shan. 33. Bogdo-Ula Range, a glacier near Lake Sangecha. 34. Lake Sangecha. 35. Sangecha Stream. 36. Bogdo-Ula Range, Zienzan Stream. 37. Karlyktag Range, Ayar-Gol Stream.