Xanthochlorus gansuensis, Qilemoge,, Chang, Wencheng & Yang, Ding, 2018

Qilemoge,, Chang, Wencheng & Yang, Ding, 2018, Two new species of the genus Xanthochlorus from China (Diptera, Dolichopodidae, Xanthochlorinae), ZooKeys 750, pp. 141-149 : 145-148

Xanthochlorus gansuensis sp. n. Figs 2-3, 7-9

Diagnosis.

First flagellomere nearly quadrate. Mid-posterior area of mesonotum blackish. Mid-basal area of scutellum blackish. Dorsal lobe of surstylus wide basally, nearly quadrate, apically concaved with two bristles; ventral lobe of surstylus wide basally, band-like, apically rounded with two bristles; cercus ovate basally, apically finger-like with bristles; hypandrium rather short with short strip-like lateral protuberance.

Description.

Male (Fig. 2). Body length 2.3-2.6 mm. Wing length 2.6-2.9 mm. Head: metallic green with pale gray pollen. Hairs and bristles on head black. Face brown with pale gray pollen, width of face equal to length of first flagellomere. Postocular bristles all yellow.Two oc, two vt. Antenna (Fig. 7) yellow; first flagellomere nearly quadrate, 0.6 times as long as wide; arista pale brown, basal segment 0.1 times as long as apical segment. Proboscis yellow with pale brown hairs; palpus yellow with pale brown hairs.

Thorax yellow with pale gray pollen. Hairs and bristles on thorax black. Mid-posterior area of mesonotum blackish; mid-basal area of scutellum blackish; pteropleuron and latero-tergite each with one black spot. 5 strong dc, acr absent, one strong h, two strong npl, one strong su, one strong prsu, one strong sa, one strong pa; scutellum with one pair of sc. Propleuron with white hairs and one long yellow bristle on lower portion. Legs yellow. Hairs and bristles on legs black. Fore coxae with 5-6 bristles; middle and hind coxae each with one outer bristle. Fore tibia without distinct bristles; middle tibia with two ad, one pd, and four apical bristles; hind tibia with three apical bristles. Mid and hind femora without preapical bristle. Relative lengths of tibia and 5 tarsomeres LI 3.0: 1.5: 0.8: 0.6: 0.4: 0.4; LII 3.8: 1.7: 0.7: 0.5: 0.4: 0.4; LIII 4.5: 1.4: 1.0: 0.7: 0.4: 0.4. Wing hyaline, veins brown; costal callus indistinct; M gently bent apically, M and R4+5 parallel apically; CuAx ratio 0.38. Squama yellow with black hairs. Halter yellow.

Abdomen yellow with pale gray pollen. Hairs and bristles on abdomen black. Male genitalia (Figs 7-9): Epandrium longer than wide; dorsal lobe of surstylus yellow, wide basally, nearly quadrate, apically concaved with two bristles; ventral lobe of surstylus pale brown, wide basally, band-like, apically rounded with two bristles; cercus ovate basally, apically finger-like with bristles; hypandrium brown, rather short with short strip-like lateral protuberance.

Female (Fig. 3). Body length 2.6 -2.8 mm. Wing length 2.7-2.9 mm.

Types.

Holotype male, CHINA, Gansu, Tianshui, Dangchuan Linchang, Maicaogou; collected by sweeping nets in grassland, 2015.VII.17, Xiaoli Li (CAU). Paratypes: nine males, 13 females, collecting information same as the holotype (CAU).

Distribution.

Palaearctic: China (Southern wet part of Gansu).

Remarks.

The new species is somewhat similar to X. henanensis Wang, Yang and Grootaert, but can be separated from the latter by the first flagellomere apically without acute corner and by the lack of acrostichals. In X. henanensis , the first flagellomere has an acute lower apical corner and 3-4 acrostichals are present ( Wang et al. 2008, Yang et al. 2011: p 1540, fig 988a).

Etymology.

The specific name refers to the type locality Gansu.