Chrysotus minuticapillatus Liu, Przhiboro & Yang, 2016

Wang, Mengqing, Liu, Ruosi, Przhiboro, Andrey & Yang, Ding, 2016, New species of Dolichopodidae from eastern Mongolia (Diptera), Zoological Systematics 41 (1), pp. 102-108 : 105-108

Chrysotus minuticapillatus Liu, Przhiboro & Yang , sp. nov. ( Figs 5–8 , 11–12 )

Male. Body length 1.8–2.2 mm, wing length 1.6–2.0 mm ( Fig. 5 ).

Head metallic-green with pale grey pollinosity; eyes contiguous on face. Hairs and bristles on head black except posteroventral hairs somewhat pale. Antenna dark brown; first flagellomere subtriangular, 1.4 times as wide as long; arista brown, short pubescent ( Fig. 7 ). Proboscis dark brown with brown hairs; palpus pale brown with one brown bristle at apex.

Thorax metallic-green with pale grey pollinosity. Hairs and bristles on thorax black; 6 dc (five strong and anterior one weak), 6–7 irregularly paired acr short and hair-like; scutellum with two pairs of bristles, basal pair long, lateral pair short; proepisternum with one long black bristle on lower part and one short black bristle on upper part.

Legs mainly brown; all trochanters yellow; base and apex of all femora yellow; fore and mid tibiae yellow, hind tibia yellow with brown apex; fore tarsomere 1 and 2 yellow (sometimes tarsomere 1 and base of tarsomere 2 yellow), mid tarsomere 1 yellow, base of hind tarsomere 1 yellow. Hairs and bristles on legs black. Fore and mid coxae with long hairs and bristles; hind coxa with one outer bristle at base. Hind trochanter with one bristle at middle. Fore femur without obvious bristles; mid femur with 1–2 av and 1 pv apically; hind femur with 3–4 av apically. Fore tibia with 1–2 weak ad and 1 weak pd, apically with 3 short bristles; mid tibia with 2 strong ad and 2–3 pd, apically with 4 bristles; hind tibia with 2 ad and 3 pd ( Fig. 8 ), apically with 3–4 bristles. Relative lengths of tibia and five tarsomeres of legs as follows: LI 4.0: 2.4: 1.1: 0.7: 0.5: 0.5; LII 5.0: 2.8: 1.3: 0.9: 0.7: 0.6; LIII 6.0: 1.8: 1.5: 0.9: 0.6: 0.6.

Wing hyaline; veins blackish, R 4+5 and M parallel apically; CuAx ratio 0.25. Squama yellow with brown hairs. Halter pale yellow.

Abdomen metallic-green with pale grey pollinosity; hairs and bristles on abdomen black.

Male genitalia ( Figs 11–12 ). Epandrium somewhat rounded, without angular projection posteriorly. Lateral epandrial lobe protruded and wide. Surstylus somewhat long and curved, tapered at apex. Postgonite developed, somewhat narrow at apex, 4–5 times as long as wide. Cercus short and wide, with medium-sized bristles. Apex of phallus with a fin-like structure.

Female ( Fig. 6 ). Body length 2.1–2.5 mm, wing length 1.9–2.3 mm. Similar to male, but eyes widely separated. Hind tibia almost entirely yellow.

Material examined. Holotype. ♂, Mongolia, Hentiy Aimag, 2 km S of Ondorhaan (47°18'N, 110°39'E; elev. 1 030 m), bank of Kerulen Gol river , net-sweeping and aspirator, 18–19 August 2002, coll. Andrey Przhiboro (no. 65) . Paratypes. 5♂ 15♀, the same data as holotype .

Distribution. Mongolia.

Etymology. The species name refers to hairs (“ minu ” (=smaller size) and “ capillum ” (=hairs)) on the apical part of hind tibia and tarsomere 1 (compare to Ch. shanxiensis Liu & Yang).

Remarks. The new species is similar to Ch. shanxiensis Liu & Yang from Shanxi in the male genitalia and antenna, but can be separated from the latter by the postgonite 4–5 times as long as wide and hairs on the apical part of hind tibia and hind tarsomere 1 of usual size and sparse ( Fig. 8 ). In Ch. shanxiensis, the postgonite 2–3 times as long as wide, and hairs on the apical part of hind tibia and hind tarsomere 1 long and dense ( Fig. 9 ).

Funding This work was partly supported by the 973 Program (2013CB127602) the National Natural Science Foundation of China (3141101151, 4151101023), the Russian Foundation for Basic Research (grants 15-54-53038 and 15-04-00732) and the Russian Scientific Foundation (grant 14-14-01134).

Acknowledgements The material was collected in the scope of the Russian-Mongolian Complex Biological Expedition. Andrey Przhiboro is grateful to M. L. Danilevskii, O. G. Gorbunov and Yu. Yu. Dgebuadze (Institute for Problems of Ecology and Evolution,Russian Academy of Sciences, Moscow) for the help in the field work. The authors are grateful to Ms. Chufei Tang ( China Agricultural University, Beijing, China) for kind help in many ways.

Figures

Figures 5–7. Chrysotus minuticapillatus Liu, Przhiboro & Yang, sp. nov. 5. Habitus, male, lateral view. 6. Habitus, female, lateral view. 7. Antenna, male, lateral view. Scale bars: 5–6=0.5 mm; 7 =0.1 mm.

Figures 8–9. Chrysotus spp., hind femur and tibia, male, lateral view. 8. Ch. minuticapillatus Liu, Przhiboro & Yang, sp. nov. 9. Ch. shanxiensis Liu & Yang. Scale bars=0.1mm.

Figures 10–12. Male genitalia. 10. Campsicnemus pallidoapicalis Wang, Przhiboro & Yang, sp. nov., lateral view. 11–12. Chrysotus minuticapillatus Liu, Przhiboro & Yang, sp. nov. 11. lateral view. 12. Apex of phallus, ventral view. Scale bars=0.1 mm.