Capnia xiei Chen & Du, sp. nov.

Figs. 13–20.

Male. Body length 4.0 mm. Forewings length 5.4 mm, hindwings length 4.5 mm. Body generally dark brown. Head rounded and slightly wider than pronotum; three ocelli pale, compound eyes black (Fig. 13). Pronotum subquadrate, anterior corners obtuse, posterior corners right-angled. Wings macropterous, hyaline with brown venation; R vein of forewing straight at its divergence with Rs; anal field of hindwing small and folded with three veins (Fig. 14). Tergal antecosta interrupted on terga 1–4, complete on terga 5–10 (Fig. 13). Legs brown to dark brown. Cerci incomplete, each segment enlarged distally (Fig. 13).

Male abdomen: Terga 2–10 with sclerotized anterior margins (Fig. 13). Tergum 9 strongly sclerotized, anteriorly indented, with an elevated posteromedial process, symmetrically triangular in lateral view (Figs. 16–17). Tergum 10 cleft with sclerotized margins. Main epiproct sclerite split mesally, basally with raised, subtriangular bilamellar structure, medially slightly widened, and apically with paired, slightly incurved, finger-shaped lobes; from lateral view, main epiproct sclerite gradually enlarged at basal ¾, then tapered to a finger-shaped apex (Figs. 15–17). Sternum 9 with an elliptical, hairy vesicle, the vesicle longer than wide, length is one third of the length of subgenital plate (Fig. 18); subgenital plate subtriangular with darkly sclerotized lateral margins; paraprocts unfused, elongated and curved (Fig. 18).

Female. Body length 5.0– 5.5 mm. Forewings length 5.5–6.0 mm, hindwings length 5.0– 5.5 mm. General color similar to male, abdominal terga 2–8 with a medial pale stripe (Fig. 19). Sternum 8 medially sclerotized; subgenital plate broad basally, then narrowed to a rectangular apex, not beyond the lateral sclerites of sternum 8; the lateral sclerites subtriangular with rounded angles (Fig. 20).

Type material. Holotype male, China: Qinghai Province, Maqin County, The Aemye Ma-chhen Range, 34°52'03'' N, 99°28'16'' E, 4500m, 8 July, 2013, Leg. Guang-lin Xie (ICYZU). Paratypes: 8 females, same locality and data as holotype.

Etymology. The species is named for Guang-lin Xie, who collected the types.

Remarks. This new species is also a member of the C. cordata species group sensu Zhiltzova (2001). It’s similar to C. yunnana in having a bifurcate epiproct, but can be distinguished by basal bilamellar structure of the high main epiproct sclerite, and by apex of epiproct shorter and not swollen. In addition, the subgenital plate of females in the new species has a rectangular apex, and posterior margin of this apex is much more flattened than that in C. yunnana (see fig. 4 in Li et al. 2011).