Chrysotus altavaginas, Liu, Ruosi, Wang, Mengqing & Yang, Ding, 2013

Liu, Ruosi, Wang, Mengqing & Yang, Ding, 2013, Chrysotus Meigen (Diptera: Dolichopodidae) from Tibet with descriptions of four new species, Zootaxa 3717 (2), pp. 169-178 : 170-173

1. Chrysotus altavaginas sp. nov.

( Figs 1 , 6–8 )

Diagnosis. First flagellomere nearly trapezoidal, 1.6 times wider than long. Legs black except fore and mid femora with yellow apices and fore and mid tibiae yellow with brown bases and apices.

Description. Male. Body length 2.1–2.2 mm, wing length 1.9–2.0 mm.

Head metallic green with pale gray pollinosity; eyes contiguous on face. Hairs and bristles on head entirely black except postero-ventral hairs pale. Antenna brown; first flagellomere nearly trapezoidal, 1.6 times wider than long; arista brown, short pubescent ( Fig. 6 ). Proboscis and palpus brown with brown hairs.

Thorax metallic green with pale gray pollinosity. Hairs and bristles on thorax black; 5 strong dc, 5 acr short and hair-like; scutellum with two pairs of bristles, basal pair short and hair-like, lateral pair long; proepisternum with 1 long black bristle on lower part and 1 short black bristle on upper part.

Legs mainly black, all trochanters brown; tips of fore and mid femora yellow; fore and mid tibiae yellow with brown base and apex; fore and mid tarsi from tip of tarsomere 1 onward black, hind tarsus entirely black. Hairs and bristles on legs black but fore coxa with brown hairs. Hind coxa with 1 black outer bristle at base. Fore tibia with 1 ad; apically with 4 short bristles. Mid tibia with 2 ad and 2 pd; apically with 4 bristles. Hind tibia with 3 pd; apically with 3-4 bristles. Relative length of tibia and 5 tarsomeres of legs LI: 4.6: 2.5: 1.2: 0.8: 0.6: 0.6; LII: 5.8: 3.2: 1.4: 1.0: 0.7: 0.7; LIII: 7.0: 2.1: 1.7: 1.1: 0.7: 0.7.

Wing hyaline, tinged brown ( Fig. 1 ); veins blackish, R4+5 and M parallel apically; CuAx ratio 0.24. Squama pale with brown hairs. Halter pale.

Abdomen metallic green with pale gray pollinosity; hairs and bristles on abdomen black. Male genitalia ( Figs 7, 8 ): Epandrium somewhat rounded, without angular projection posteriorly. Hypandrium with acute end, far from distal margin of lateral epandrial lobe. Lateral epandrial lobe short wide, with 2–3 hairs at apex. Surstylus wide basally, somewhat tapered apically. Cercus somewhat short, with moderately long bristles. Apex of phallus with deeply hollow apex.

Distribution. China (Tibet).

Etymology. The specific epithet refers to the deeply hollow apex of phallus. Remarks. The new species is similar to Chrysotus sinuolatus Wang & Yang in the nearly trapezoidal first flagellomere and wide lateral epandrial lobe, but can be separated from the latter by the deeply hollow apex of phallus. In C. sinuolatus , the apex of phallus is not hollow but is curved and protruding (Yang et al. 2011).

2. Chrysotus biprojicienus Wei & Zhang ( Figs. 2 )

Chrysotus biprojicienus Wei & Zhang, 2010: 10 . Type locality: China: Guizhou, Shibing, Yuntaishan.

Diagnosis. Femora blackish; tibiae yellow except bases of all tibiae and apex of hind tibia blackish. Epandrium with angular projection posteriorly. Hypandrium with somewhat pointed end, slightly projecting beyond level of waved distal margin of lateral epandrial lobe. Apex of phallus with two lateral lobes.

Specimens examined. 5♂ 2♀, China: Tibet, Linzhi, Motuo 80K, 29°33′N, 95°32′E, 1000 m, 2012. VIII.5–10, X.K. Li.

Distribution. China (Tibet, Guizhou).

Figures

FIGURES 1 – 5. habitus photographs: 1, Chrysotus altavaginas sp. nov. (male), scale bars = 0.5 mm; 2, Chrysotus biprojicienus Wei & Zhang, scale bars = 0.5 mm; 3, Chrysotus motuoensis sp. nov. (male), scale bars = 0.5 mm; 4, Chrysotus namaicunensis sp. nov. (male), scale bars = 0.5 mm; 5, Chrysotus tibetensis sp. nov. (male), scale bars = 0.5 mm.

FIGURES 6 – 8. Chrysotus altavaginas sp. nov. (male): 6, first flagellomere, lateral view, scale bars = 0.1 mm; 7, genitalia, lateral view, scale bars = 0.1 mm; Abbreviations: cer, cercus; epn, epandrium; hyp, hypandrium; lel, lateral epandrial lobe; pg, postgonite; ph, phallus; sur, surstylus. 8, apex of phallus, lateral view, scale bars = 0.05 mm.