Mesoperlina pecirkai Klapalek 1921

Mesoperlina pecirkai Klapálek, 1921

Figs. 31–32

Klapálek, 1921:148; Illies, 1966:424, 425; Zhiltzova, 1970:587, figs. 14–17; Zwick, 1973:253, 254; Teslenko & Zhiltzova, 2009:49, figs. 272–275.

Material examined. China, the Xinjiang Uygur Autonomous Region, Eastern Tien Shan: 1 female, 1 exuvia, Bogdo-Ula Range, Urumqi city, Dabancheng District, Sangecha River, 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.

Notes. The assignment of the female to M. pecirkai was based on body size, color pattern, and shape of the genital plate. Mesoperlina pecirkai differs from other known members of the Mesoperlina in having the largest body size and wingspan. The shape of the female genital plate, color pattern of the head, the body and wingspan from Sangecha stream agree with the redescription and illustrations (Zhiltzova 1970).

Female. The body is 16.0 mm in length, macropterous, and has a forewing length of 14.1 mm, and wingspan of 30.2 mm. The head bears a distinct brown M-line and brown, arcuate bands connect the posterior ocelli with the tentorial callosities in front (Fig. 31). The clypeus is brownish above M-line corners. The interocellar area is a large, triangular, pale spot, and nearly enclosed by pigment posteriorly (Fig. 31). The lateral margins with pale areas extending from compound eyes to the M-line bases. The occiput has two oval brown spots and two transverse brown bands curved along the stem and covered with brown spines. The spinule row is interrupted medially. The epicranial suture is pale (Fig. 31). The pronotum is brown, with wide, pale medial stripe, laterally pronotum with dark rugosities on a pale brown background (Fig. 31). The abdomen is paler than other parts of the body. Sternum 8 yellow with a round brown area medially. The subgenital plate is short, round, and extends beyond sternum 8 covering about one third of sternum 9, and bears a few thin transverse wrinkles at the base (Fig. 32). The posterior margin of the subgenital plate is slightly pigmented posterolaterally (Fig. 32).

Distribution and ecology. Mesoperlina pecirkai is one of the most common and numerous species found in Central Asia. The species is widespread in the running waters of the Pamir, Hindu Kush, the Western and Central Tien Shan, including the Naryn River basin bordering the Xinjiang Uygur Autonomous Region in China where the female was collected in Bogdo-Ula Range. Emergence extends from mid-May to late July. Mesoperlina pecirkai inhabits cold mountain rivers and streams at the altitudes of 800 to 2,700 – 3,000 m above sea level. Unlike the other species of the genus, M. pecirkai may range high into the mountains, without going down beyond the foothill belt (Zhiltzova 1970). This is the first report of M. pecirkai in the Eastern Tien Shan and stonefly fauna of China. The female and exuvia were found at the upper section of mountain Sangecha Stream that drains the glacier Sanchecha Lake and flows down between the mountain slopes which are covered with grass at an altitude 2,356 m above sea level (Fig. 35). The Sangecha Stream has a fast current, the substrate consists of large boulders and cobbles, and a riparian gallery of trees (Fig. 35). Mesoperlina pecirkai was collected with N. lepnevae and F. wusuensis.