Semachrysa pura Wu & Liu, 2024, sp. nov.

[63] Semachrysa pura sp. nov. (Figs 72, 89) Diagnosis. This species is characterized by the head with black spots only on the gena, the antennae without brown stripe, the thorax without markings, the forewing with brown shadings on apical radial crossveins, base of Rs, inner gradate series, CuP and 4th posterior margin crossveins, the median arch of male gonarcus with small projections, the narrow triangular entoprocessus, the long curved arcessus widest at middle and pointed at tip, the extremely long female vela, and the deep ventral impression. Description. Male. Body length 7.2 mm, forewing length 11.0 mm, hindwing length 9.5 mm. Head with black spots only on gena. Compound eyes prominent and black. Antennae yellow, scape and pedicel wider than flagellum. Frons and clypeus without spots. Maxillary and labial palpi with brown stripes on outer side. Pronotum anterior margin shorter than posterior margin, not marked; mesonotum and metanotum without markings. Legs with dense setae, without spots. Pretarsal claws brown, with basal dilation. Forewing with brown shadings on apical radial crossveins, base of Rs, inner gradate series, CuP and 4th posterior margin crossveins. Pterostigma indistinct. Costal area with 18–21 crossveins; 11–12 radial crossveins present. m1 smaller than m2; im ovoid; 8 psm-psc crossveins present. c1 smaller than c2, dcc opened. A1 forked, A2 and A3 simple. Inner gradate series with brown shadings, especially distal crossveins; outer gradate series with 6–8 crossveins. Hindwing without shadings. Costal area with 18 crossveins; 10–11 radial crossveins and 6–7 psm-psc crossveins present. Inner gradate series with 5–8 crossveins, outer gradate series with 6–7 crossveins. Abdomen with dense setae. Tergum VII and sternum VII subquadrate in lateral view; tergum VIII shorter than tergum VII; sternum VIII fused with sternum IX; tergum IX fused with ectoproct. Callus cerci ovoid. Gonarcus arcuate, median arch with small projection, lateral arms narrow at base and wide at tip; entoprocessus narrow and triangular; arcessus long and curved, widest at middle and pointed at tip. Female. Body length 8.1–8.6 mm, forewing length 10.8–11.9 mm, hindwing length 9.6–10.5 mm. Sternum VII longer than tergum VII; tergum VII subquadrate in lateral view; tergum VIII shorter than tergum VII; tergum IX fused with ectoproct. Callus cerci ovoid. Subgenitale bilobed apically; spermatheca thick, vela extremely long, ventral impression deep, duct long and coiled. Type material. Holotype ♂, China, Xizang, Mêdog, 80K, light, 2115 m, 2018.VII.31, Xingyue Liu (CAU). Paratypes: 2♀, same as holotype, Xingyue Liu & Hongyu Li (CAU); 1♀, China, Xizang, Mêdog, Pêlung, 2013. IX.10, Gang Yao (CAU). Etymology. The specific epithet ‘ pura ’ refers to the absence of spots on vertex, frons and thorax on the news species. Distribution. China (Xizang). Remarks. This species, unlike other species of Semachrysa with many spots on the head and thorax, has spots only on the gena, and there are no markings on the thorax. This species can be distinguished easily by the extremely long female vela, the triangular male entoprocessus and the curved arcessus.