Zygoneura (Zygoneura) occidens Zhang & Wu, sp. nov.

Specimens examined. Holotype, male. China, Sichuan province, Yaan, Labahe, 1200m, 29°59΄N, 102°59΄E 16.VII.2006, Xiao-Ling Niu [SM00946]. Paratype. 1 Male, China, Tibet province, Linzhi, Mafenggou, 29°50΄N, 93°25΄E, 3.VI.1978, Fa-Sheng Li [SM00947].

Description (Male). Body length 2.60 mm. Color: Head and thorax dark brown; palpus, antenna, coxae, abdomen and hypopygium yellowish-brown; legs yellow; wing fumose. Head (Fig. 3 A, B): Eye bridge broad, with three rows of facets. Prefrons with eight setae. Palpus three-segmented, basal segment with two setae, 2nd segment with four setae, 3rd segment with seven setae. Flagellomeres with long setae subequal in length. The 4th flagellomere 0.14 mm in length, length/width: 3.2, neck of flagellomere 0.06 mm and nearly 1/2 the length of the flagellomere. Thorax: Posterior pronotum and mediotergite bare. Scutellum with two setae. Apex of fore tibia with a broad comb-like row of setae (Fig. 3 C): Length of spur/width of tibia: fore leg 1.67, hind leg 1.02; length of metatarsus/length of tibia: fore leg 0.61, hind leg 0.43; length of hind tibia/length of thorax: 1.42. Tarsal claws three-toothed. Wings (Fig. 3 D): Wing length 1.78, width/length: 0.38. M1, M2, r-m and CuA1 with no setae. stM not clearly visible in the specimen. c/w: 0.75. R1/R: 0.65. Terminalia: Ventral mesial margin of gonocoxa with two groups of weak setae, the angulate lobe-like part not conspicuous (Fig. 3 E). Gonostylus oval, almost as long as the gonocoxa, bearing a pair of long megasetae and another longer megasetae near the apical third (Fig. 3 F). Tegmen somewhat higher than broad.

Female. Unknown.

Remarks. The species belongs to the subgenus Zygoneura; it is similar to Z. sciarina in having three megasetae at the gonostylus, a bare posterior pronotum, and a scutellum with two setae (Menzle & Mohrig 2000). It can be recognized by the oval gonostylus and pair of long megasetae and another longer megasetae near the apical third. Moreover, the angulate lobe-like part in the new species is inconspicuous, unlike the other species of the subgenus.

Etymology. The species is named after its distribution (western China).