Three new species of Argyra from China (Diptera, Dolichopodidae, Diaphorinae)

Abstract Previously, there were ten known species in the genus Argyra Macquart from China. In this paper, the following three species from Sichuan Province of China are described as new to science: Argyra longicornis sp. n., Argyra pingwuensis sp. n. and Argyra sichuanensis sp. n. A key to the known species of Argyra from China is provided.

Sichuan province is located in southwest China, covering an area of 48,000 square kilometers. The topography of Sichuan varies from mountains to basins, undulating with plateaus and hills. Usually, this region has typical subtropical monsoon climate. These patterns together contribute to the rich species diversity of insects. Here Argyra is reported for the first time from Sichuan with three new species.

Materials and methods
The specimens upon which this study is based, were collected from Sichuan province of China in 2016 by sweep nets and yellow pan traps. After the genitalia was dissected, it was placed in a small centrifuge tube containing glycerin and stored in glass tube containing the corresponding specimen (all specimens were stored in alcohol) and deposited in the Entomological Museum of China Agricultural University (CAU), Beijing. Morphological terminology for adult structures mainly follows McAlpine (1981). Terms for the structures of the male genitalia follow Cumming and Wood (2009 First flagellomere much elongated, 3.8 times longer than wide ( All femora black, only apical 1/4 of fore femur yellow; apical 1/3 of hind tibia black (Fig. 5); fore tarsomere 2 slightly thickened with short thick bristles; dorsal lobe of surstylus strip-like, apical unobviously inflated (Fig. 13)  Abdominal tergites 1-2 with large yellow lateral spot; basal 1/3 of fore and mid femora and apical 1/3 of hind femur black; apical 1/4 of hind tibia black (Fig. 3); ventral lobe of surstylus ventrally with 1 protuberance (Fig. 11)  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   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, fingerlike, 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.
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(Yang et al. : 1106 fig. 713a-b).
Etymology. The specific name refers to the elongated first flagellomere.
Thorax metallic green with pale gray pruinescence. Hairs and bristles on thorax black. Five strong dc, six acr, two strong npl, one strong sa, two strong pa; scutellum with two pairs of sc. Propleuron with one pale bristle. Legs with all coxae black; basal 1/3 of fore and mid femora black, apical 1/3 of hind femur black; fore and mid tibiae yellow, apical 1/4 of hind tibia black; fore and mid tarsi from tip of tarsomere 1 onward black, hind tarsus entirely black. Hairs and bristles on legs black. Fore coxa with two bristles, mid coxa with five bristles, hind coxa with two black outer bristles. All femora with two rows of long black ventral bristles, twice as long as width of femur. Fore tibia with one ad, two pd, and three apical bristles; mid tibia with two ad, four pd, three av, and five apical bristles; hind tibia with eight ad, eight pd, av absent and three apical bristles. Relative lengths of tibia and 5 tarsomeres LI 3.2 : 2.3 : 0.5 : 0.4 : 0.2 : 0.3; LII 5.2 : 3.1 : 1.2 : 1.0 : 0.6 : 0.4; LIII 6.7 : 2.4 : 1.7 : 1.2 : 0.7 : 0.5. Wing hyaline, veins black; costal callus indistinct; M bent medially, M and R 4+5 parallel apically; CuAx ratio 0.43. Squama yellow with brown hairs. Halter yellow.
Distribution. Oriental realm: China (Sichuan). Remarks. The new species is somewhat similar to A. beijingensis Wang & Yang, but can be separated from the latter by the following features: fore and mid femora black at base 1/3, hind femur black at apical 1/3, hind tibia black at apical 1/4; dorsal lobe of surstylus with one long bristle. In A. beijingensis, the ventral surface of the fore and mid femora are black at base, the hind femur is black at apical 1/5; the dorsal lobe of the surstylus has three bristles (Wang et al. 2004: 386, fig. 2;Yang et al. 2011Yang et al. : 1106 . 714).
Etymology. The specific name refers to the type locality, Pingwu.
Thorax metallic green with pale gray pruinescence. Hairs and bristles on thorax black. Five strong dc, six acr, two strong npl, one strong sa, two strong pa; scutellum with two pairs of sc. Propleuron with one pale bristle. Legs mostly black. All coxae black; all femora black except apical 1/4 of fore femur yellow; all tibiae yellow except apical 1/3 of hind tibia black; fore and mid tarsi from tip of tarsomere I onward black, hind tarsus entirely black. Hairs and bristles on legs black. Fore coxa with eight bristles, mid coxa with six bristles, hind coxa with four outer bristles. All femora with two rows of long ventral bristles, twice as long as width of femur. Fore tibia with one ad, four pd, and three apical bristles; mid tibia with one ad, three pd, three av, and three apical bristles; hind tibia with five ad, six pd, av absent and four apical bristles. Fore tarsomere II slightly thickened with short thick bristles. Relative lengths of tibia and 5 tarsomeres LI 2 Abdomen metallic green with pale gray pruinescence. Abdominal tergite II with large yellow lateral spot. Hairs and bristles on abdomen black. Male genitalia (Fig. 13): Surstylus deeply incised apically; dorsal lobe brown, nearly strip-like, with one apical bristle; ventral lobe yellow, finger-like, basally wide, with two bristles. Cercus long, medially wide, with distinct bristles. Hypandrium yellow, long, medially bent, apically rounded. Female (Fig. 6). Body length 5.4-5.6 mm. Wing length 5.4-5.6 mm. Fore coxa yellow except basally black. Hind femur black apically; hind tibia yellow except apical 1/5 black. Fore tarsomere II normal without short thick bristles. Abdomen without yellow lateral spot.
Types. Holotype male, CHINA, Sichuan, Pingwu, Wanglang National Nature Reserve, Baixionggou; 2857 m; collected by sweeping nets in grassland; 2016.VIII.06, Yuqiang Xi. Paratypes: 17 males, 448 females, same data as holotype. Distribution. Oriental realm: China (Sichuan). Remarks. The new species is somewhat similar to A. beijingensis Wang & Yang, but can be separated from the latter by the following features: all femora black, only fore femur yellow at apical 1/4; hind tibia apically black; fore tarsomere II slightly thickened with short thick bristles; dorsal lobe of surstylus apically unobviously inflated, nearly strip-like, with one apical bristle. In A. beijingensis, the ventral surface of the fore and mid femora are black at base, the hind femur is black at apical 1/5; the dorsal lobe of the surstylus is wide, apically distinctly inflated with three bristles (Wang et al. 2004: 386, fig. 2; Yang et al. 2011Yang et al. : 1106 fig. 714).
Etymology. The specific name refers to the type locality, Sichuan province.