(Figs. 33–35)

Type material. Holotype. China: Male, Xizang, Chayu, Xiachayu, vi-7-2019, Libin Ma coll. (SNNU). Paratypes. 3 males & 2 females, same information as holotype.

Description. Male. Body size small. Head small, slightly wider than the anterior of pronotum. Rostrum slightly wider than antennal scape. Median ocellus half-round and smallest, lateral ocelli round. Eyes rather large. Postclypeus transverse wide and anteclypeus concave medially. Apical joint of maxillary palpi slightly longer than the third, depressed and widened, with rounded apex; apical joint of labial palpi rod-like, longer than remainder sections, depressed and widened. Pronotum transverse wide, trapezoidal; anterior margin straight and the posterior somewhat convex, posterior margin wider than the anterior, middle of both lateral edges slightly concave. Tegmen bearing an oblique vein and three chord veins. Dividing vein longitudinal and separating mirror as left and right cells. Apical region degraded, lateral region bearing four Sc branches. Fore tibia only possessing external tympanum, elongate oval-like. Hind tibia bearing four dorsal spurs inside and three outside, first of the inside stubby and far away from others; apical spurs three on both sides respectively, first of the inside longest.

Genitalia. Epiphallus extremely narrowed, lateral lobe rather long. Ectoparamere shaped as triangular sheet, inside protruded.

Female. Similar to male but tegmen rather short, bearing few transverse veins and primary veins almost paralleled. Ovipositor blade shape.

Coloration. Body colored dark brow. Legs colored yellowish brown.

Measurements (mm). Male (n=4). BL 4.68±0.53, HW 1.38±0.15, PL 1.41±0.12, TL 2.89±0.36, HFL 3.41±0.45. Female (n=2). BL 4.46±0.31, HW 1.47±0.26, PL 1.08±0.20, TL 2.01±0.33, HFL 3.53±0.42, OL 2.13±0.36.

Etymology. The name refers to the type locality of Chayu County.

Remarks. This species is very similar to Polionemobius taprobanensis (Walker, 1869) and Polionembius yunnanus Liu & Shi, 2014 in ectoparamere of male genitalia, but its epiphallic median lobe not obvious. It is similar to P. yunnanus in coloration of body, but differs in coloration of fourth joint of maxillary palpi (the new species colored dark, P. yunnanus colored light).