Argyra longicornis, Qilemoge,, Wang, Mengqing & Yang, Ding, 2018

Qilemoge,, Wang, Mengqing & Yang, Ding, 2018, Three new species of Argyra from China (Diptera, Dolichopodidae, Diaphorinae), ZooKeys 772, pp. 141-151 : 141

Argyra longicornis sp. n. Figs 1-2, 7-9

Diagnosis.

First flagellomere much elongated, 3.8 times longer than wide; arista with basal segment 0.2 times as long as apical segment. Fore coxa yellow, mid and hind coxae black; hind femur black apically; fore tarsus yellow, mid tarsus from tip of tarsomere IV onward black. Hind tibia with 12 av; hind tarsomere I with six dorsal bristles and eight ventral bristles. CuAx ratio 0.52. Abdominal tergites 2-3 with large yellow lateral spot. Surstylus shallowly incised apically; dorsal lobe thumb-like; ventral lobe finger-like; cercus foliate.

Description.

Male (Fig. 1). Body length 5.2 mm. Wing length 5.4 mm.

Head metallic green with pale gray pruinescence. Hairs and bristles on head black. Face brown with pale gray pruinescence, width of face equal to length of first flagellomere. Upper postocular bristles black, middle and lower postocular bristles yellow. Two oc, two vt, two pvt. Antenna (Figs 2, 7) brown; scape with black hairs, pedicel with circlet of black hairs; first flagellomere much elongated, 3.8 times longer than wide, apically slightly sharp; arista brown, indistinctly pubescent, basal segment 0.2 times as long as apical segment. Proboscis brown with black hairs; palpus black with black hairs.

Thorax metallic green with pale gray pruinescence. Hairs and bristles on thorax black. Five strong dc, four acr, two strong npl, one strong sa, two strong pa; scutellum with two pairs of sc. Propleuron with one pale bristle. Fore coxa yellow, mid and hind coxae black; fore and mid femora yellow, hind femur black apically; fore and mid tibiae yellow, hind tibia black apically; fore tarsus yellow, mid tarsus from tip of tarsomere IV onward black, hind tarsus entirely black. Hairs and bristles on legs black. Fore coxa with three bristles, mid coxa with three bristles and hind coxa with three black outer bristles. All femora with two rows of long black ventral bristles, length of bristles equal to width of femur. Fore tibia with five ad, six pd, three av, and three apical bristles; mid tibia with two ad, four pd, three av, and five apical bristles; hind tibia with four ad, five pd, 12 av, and two apical bristles. Hind tarsomere 1 with six dorsal bristles and eight ventral bristles. Relative lengths of tibia and 5 tarsomeres LI 3.5: 2.4: 0.7: 0.5: 0.3: 0.4; LII 4.8: 2.1: 1.0: 0.9: 0.6: 0.4; LIII 6.7: 2.3: 0.9: 0.9: 0.5: 0.3. Wing hyaline, veins black; costal callus indistinct; M bent medially, M and R4+5 parallel apically; CuAx ratio 0.52. Squama yellow with black hairs. Halter yellow.

Abdomen metallic green with pale gray pruinescence, except tergites 2-3 with yellow lateral spot. Hairs and bristles on abdomen black. Male genitalia (Figs 8-9): Surstylus on epandrium shallowly incised apically, extending to midlength; dorsal lobe brown, thumb-like, apically sharp, with two bristles; ventral lobe brown, finger-like, basally wide with one long strong bristle, apically sharp with one bristle. Cercus foliated, long, basally wide, apically slightly acute with distinct bristles. Hypandrium yellow, long and slightly bent medially.

Female. Unknown.

Types.

Holotype male, CHINA, Sichuan, Chongzhou, Jiguanshanxian, Anzihe Nature Reserve; 1690 m; collected by sweeping nets in grassland; 2016.VII.30, Yuqiang Xi.

Distribution.

Oriental realm: China (Sichuan).

Remarks.

The new species is somewhat similar to A. arrogans Takagi, but can be separated from the latter by the following features: first flagellomere much elongated, 3.8 times longer than wide (Figs 2, 7); fore coxa yellow, mid and hind coxae black (Fig. 1); ventral lobe of surstylus with one long strong bristle at base; cercus foliated (Fig. 9). In A. arrogans , the first flagellomere is as elongate, 2.1 times longer than wide; all coxae are black; the ventral lobe of the surstylus has two long strong bristles at base; and the cercus is nearly quadrate with the sharp apex ( Yang et al. 2011: 1106, fig. 713 a–b).

Etymology.

The specific name refers to the elongated first flagellomere.