Xanthochlorus tewoensis, 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 : 143-145

Xanthochlorus tewoensis sp. n. Figs 1, 4-6

Diagnosis.

First flagellomere nearly quadrate. Mid-posterior area of mesonotum yellow. Mid-basal area of scutellum yellow. 1st to 4th tergites of abdomen pale yellow. Dorsal lobe of surstylus wide basally and sharp towards tip, with one bristle apically; ventral lobe of surstylus wide basally, with two apical protuberances; cercus small, nearly quadrate, weakly concave at middle dorsally; hypandrium straight, round apically.

Description.

Male (Fig. 1). Body length 3.0-3.2 mm. Wing length 3.3-3.8 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. 4) yellow; first flagellomere nearly quadrate, 0.57 times as long as wide; arista brown, basal segment 0.09 times as long as apical segment. Proboscis yellow with yellow hairs; palpus yellow with yellow hairs.

Thorax yellow with pale gray pollen. Hairs and bristles on thorax black. Pteropleuron and latero-tergite each with a single black spot. Five strong dc, acr absent, one strong h, two strong npl, one strong su, one strong prsu, one strong sa, one strong pa; scutellum with a pair of sc. Propleuron with white hairs and a long yellow bristle on lower portion. Legs yellow. Hairs and bristles on legs black. Fore coxa with six bristles; middle and hind coxae each with a single black outer bristle. Fore tibia without distinct bristle; middle tibia with one ad, one pd, and four apical bristles; hind tibia with two apical bristles. Mid and hind femora without preapical bristles. Relative lengths of tibia and 5 tarsomeres LI 6.0: 4.0: 1.6: 1.2: 0.8: 0.7; LII 6.0: 4.0: 1.6: 1.2: 0.8: 0.7; LIII 9.4: 2.8: 1.9: 1.2: 0.8: 0.6. Wing hyaline, veins brown; costal callus indistinct; M gently bent apically, M and R4+5 parallel apically; CuAx ratio 0.47. Squama yellow with yellow hairs. Halter yellow.

Abdomen yellow with pale gray pollen, tergites 1-4 pale yellow. Hairs and bristles on abdomen black. Male genitalia (Figs 4-6): Epandrium longer than wide; dorsal lobe of surstylus yellow, basally wide, nearly quadrate, apically sharp with one bristle; ventral lobe of surstylus pale brown, wide, apically with two protuberances; cercus small, nearly quadrate with distinct bristles, but weakly concave at middle dorsally; hypandrium light brown, straight, round apically.

Female. Unknown.

Types.

Holotype male, CHINA, Gansu, Tewo, Lazikoulinchang, Laolazi, collected by sweeping nets in grassland, 2015.VII.26, Qingxia Zhou (CAU). Paratypes: two males, collecting information same as the holotype (CAU).

Distribution.

Palaearctic: China (Southern wet part of Gansu).

Remarks.

The new species is somewhat similar to X. chinensis Yang and Saigusa, but can be separated from the latter by the quadrate first flagellomere, the yellow mid-posterior area of the mesonotum and the two protuberances on the ventral lobe of the surstylus. In X. chinensis , the first flagellomere is semicircular, the mid-posterior area of the mesonotum is black, and the ventral lobe of the surstylus is irregularly furcated at tip ( Yang and Saigusa 2005, Yang et al. 2011: p 1539, fig 987b).

Etymology.

The specific name refers to the type locality of Tewo.