Sweltsa taibaishana Zhang, Li & Li, sp. nov.

(Figs. 4–5, 6c–6d)

Adult habitus. (Figs. 4a–4b). Generally pale in ethanol. Head: the typical brown cephalic marking large, continuous, laterally constricted near anterior ocellus and triangularly notched between posterior ocelli; compound eyes black, ocelli with dark rings; antennae pale, distal flagella brownish, scape and pedicel brown (Fig. 4a). Pronotum with continuous dark brown margins and obscure midline and paramedial markings. Wing membrane transparent (Fig. 4b); legs pale. Abdominal tergum 1 with anterior and lateral margins brown, and narrower median stripe, terga 2–7 with brown trapezoidal median stripe. Cerci pale with long setae.

Male. (Figs. 5, 6c–6d). Forewing length 9.7 mm; hindwing length 8.4 mm. Tergum 8 with brown median band at anterior margin. Tergum 9: transverse ridge distorted, band-shaped (Figs. 5a–5b). Sternum 9: subgenital plate tongue-shaped, with rounded posterior margin (Fig. 5e). Epiproct recurved, slender and rod-like, medially slightly constricted, apex gently tapering in dorsal aspects; in lateral aspect up-curved distally, nearly parallel-sided at basal half, apex widened and truncate (Figs. 5c–5d, 6c–6d).

Female. Unknown.

Type Material. Holotype male (CAU), CHINA: Shaanxi Province, Zhouzhi County, Qinling Mountains, Taibaishan National Natural Reserve, 1711 m, 33.8847 N, 107.8108 E, 2015.VII.30, Xuankun Li.

Etymology. The specific name refers to the mountain Taibaishan where the holotype was collected.

Distribution. China (Shaanxi Province).

Remarks. The epiproct of Sweltsa taibaishana sp. nov. is similar to S. baiyunshana Li, Yang & Yao, 2014 . However, S. taibaishana may be easily separated from S. baiyunshana by the following features: the median portion of epiproct is narrower than base and subapical portion in dorsal view; the swollen apical half is nearly parallel-sided in lateral view. In S. baiyunshana, the median portion of the epiproct is parallel-sided in dorsal view, and the apical 1/4 of epiproct is gradually enlarged; apically, the epiproct has an upraised tongue-like cap in lateral view.