Chrysotus agraulus, Wei, Lianmeng & Zhang, Lili, 2010

Wei, Lianmeng & Zhang, Lili, 2010, A taxonomic study on Chrysotus Meigen (Diptera: Dolichopodidae) from southwest China: descriptions of eleven new species belonging to the redefined C. laesus - group, Zootaxa 2683, pp. 1-22 : 6-7

2. Chrysotus agraulus sp. nov.

( Fig. 2 )

Diagnosis. Eyes contiguous on face. Postocular setae black. Proboscis brown, palpus brown. All coxae blackish; femora blackish. Squama pale with brown setulae. Halter pale. Male terminalia with very large and wide ventral projection of the epandrium and proximal portion of hypandrium seldom with projection.

Description. Male: Body length 2.1 mm, wing length 1.9 mm. Head: Metallic green with pale gray pollinosity; eyes contiguous on face. Setulae and setae on head black, postocular setae (including posteroventral setulae) black. Antenna black; first flagellomere subtriangular, 0.85 times as long as wide; arista black, short pubescence. Proboscis brown with black setulae; palpus brown with 1 black apical seta. Thorax: Dark metallic green with pale gray pollinosity. Setulae and setae on thorax black; 6 strong dc, 7–8 irregularly paired acr short and setula-like; scutellum with 2 pairs of setae, basal pair short and setula-like; propleuron with 1 black setula and 1 black seta on lower part. Legs: Brown, all coxae and trochanters blackish, with dark metallic green; femur brownish black, with dark metallic green; tibiae blackish yellow; all tarsi from tip of tarsomere 1 onward brownish. Setulae and setae on legs black. Mid and hind coxae each with 1 outer seta. Fore femur with 2 pv apically; hind femur with 2–3 av and 2 pv apically. Fore tibia with 1 ad, apically with 3 short setae; mid tibia with 2 ad and 2 pd, apically with 4 setae; hind tibia with 2 ad and 5 pd, apically with 4 setae. Relative lengths of tibia and 5 tarsomeres of legs LI 62: 30: 18: 12: 9: 8; LII 78: 38: 17: 12: 9: 9; LIII 90: 28: 20: 12: 9: 9. Wing: Hyaline, veins brown; R4+5 and M1+2 parallel apically, CuAx ratio 0.28. Squama pale with brown setulae. Halter pale. Abdomen: Dark metallic green with pale gray pollinosity; setulae and setae on abdomen black. Male terminalia ( Fig. 2 ). Epandrium with angular projection posteriorly. Ventral projection of epandrium very large, with end flat and wide, and stands at level of distal margin of lateral epandrial lobe. Lateral epandrial lobe rounded arch, bearing 2 setae. Surstylus relatively thin and long, base widened and slightly curved apically. Cercus short and wide, with moderately long setae. Hypandrium with ventral process pointed apically. Proximal portion of hypandrium without projection. Postgonite with strip-like arms and knife-like anterior process, all projections subequal in length. Female: Unknown.

Type material. HOLOTYPE ɗ, Guizhou: Anshun, Ganpu, 1250 m, 26º07’N, 106º05’E, 3.VIII.1993, LM Wei. PARATYPE: 1 ɗ, same as holotype.

Etymology. From the Greek agraulus , meaning “living in field; farm”.

Remarks. According to the key of Negrobov et al. (2000), the new species will run to C. nudisetus Negrobov et Maslova, 1995 , but differs from the latter by the very large ventral projection of the epandrium, with end flat and wide, and stands at level of distal margin of lateral epandrial lobe; hypandrium with ventral process pointed apically.

Based on the key of Becker (1922), the new species will run to couplet 3, but differs from all species under the couplet by blackish brown femora and yellow tibiae.

Figures

FIGURE 2. Chrysotus agraulus sp. nov., male terminalia, left lateral view. Abbreviations: apgon, arms of postgonite; appgon, anterior process of postgonite; cerc, cercus; ejap, ejaculatory apodeme; hyp, hypandrium; lel, lateral epandrial lobe; ph, phallus; peap, posterior epandrial angular projection; sur, surstylus; vpe, ventral projection of epandrium.