Neoperla jiaoxihe Li & Yan 2021, sp. nov.

(Figs. 3–4, 5c)

Adult habitus. (Figs. 4, 5c). Brown species with darker head pattern (Fig. 5c): head a darker brown subtriangular marking forward of M-line, interocellar area dark brown (Figs. 4a, 5c). Distance between ocelli subequal to width of one ocellus. Compound eye black, antennae dark brown (Fig. 4c); palpi brown. Pronotum generally brown, with pale brown area between lateral margin and paramedial rugosities, and darker stripe at midline (Fig. 4a); wing subhyaline, veins brown. All legs brownish with knees only slightly darker (Fig. 4c). Cercus brownish (Fig. 4b).

Male. (Figs. 3–4). Forewing length 12.6 mm. Process of tergum 7 a broadly rounded, sclerotized lobe with two patches of dense sensilla basiconica separated medially (Fig. 3b). Tergum 8 medially with a tongue-shaped process covered with several spines on the anterior surface (Figs. 3b, 3c). Tergum 9 depressed medially. Hemitergal process of tergum 10 finger-like, slightly curved laterally at middle and medially near apex (Fig. 3b).

Aedeagus (Fig. 4). Aedeagal tube with sclerotized dorsal surface and completely sclerotized apex, the sclerotized surface mostly covered with punctuations (Figs. 3a, 3c, 3d). Aedeagal sac 1.5X tube length, ventral surface of basal half covered by dense small spines, larger hooks arranged into two narrowly separated patches of ca. 10–12 spines and a subapical ring of ca. 12 large hooks and several smaller ventral spines (Figs. 4c–4e); a pair of apical sclerites successfully everted: in lateral aspect paired overlapping triangular sclerites (Fig. 4a), but in ventral view a pair of medially separated, subrectangular sclerites (Figs. 4d–4e).

Female. Unknown.

Type material. Holotype: male (HIST), China: Shaanxi, Foping County, Jiaoxihe River, 33.5227° N, 107.9831° E, 836 m, 2021.VI.7, Weihai Li.

Etymology. The specific epithet refers to the type locality, Jiaoxihe River.

Distribution. This species is only known from the type locality, which is located in the south slope of Qinling Mountains in Shaanxi Province. The holotype was collected from the handrail of Jiaoxihe bridge located in the center of the county. The river is about 50 meters wide, and the riverbed is stony with sparse grass and small trees. The flow is decreased at the type locality because of an artificial dam for tourism.

Diagnosis and remarks. The armature of the aedeagal sac includes paired apical sclerites, this and the head pattern suggest membership in the N. sinensis subgroup. It is most similar to N. bilineata Wu & Claassen, 1934, from Sichuan and N. nigromarginata Li & Zhang, 2014, of Henan. However, it lacks the paired paramedial processes of tergum 7 present in those two species. We tentatively assign this species the N. sinensis subgroup on the basis of the apical paired aedeagal sclerites and head pattern.