Chrysotus adunatus, 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 : 5-6

1. Chrysotus adunatus sp. nov.

( Fig. 1)

Diagnosis. Eyes contiguous on face. Postocular setae black. Palpus brown. All coxae blackish, femora blackish, apex of mid and hind tibiae brownish. Squama yellow with black setulae. Halter pale. Male terminalia with surstylus almost straight (only base and pointed apex bent) and hypandrium with bananashaped dorsolateral projection, which is unique among all species in this group.

Description. Male: Body length 2.8 mm, wing length 2.2 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, 0.8 times as long as wide; arista black, short pubescence. Proboscis brown with brown setulae; palpus brown with 1 black apical seta. Thorax: Dark metallic green with pale gray pollinosity. Setulae and setae on thorax black; 6 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: Blackish brown, all coxae and trochanters blackish (fore coxa paler); femora blackish (fore femur paler); tibiae yellow with base brownish, hind tibia brown apically; apex of mid and hind tibiae brownish; all tarsi from tip of tarsomere 1 onward brownish to brown. Setulae and setae on legs black. Mid and hind coxae each with 1 outer seta. Mid femur with 2 av and 3 pv apically; hind femur with 2 av apically. Fore tibia with 1 ad, apically with 3 short setae; mid tibia with 3 ad, apically with 4 setae; hind tibia with 2 ad and 3 pd, apically with 4 setae. Relative lengths of tibia and 5 tarsomeres of legs LI 40: 20: 10: 6: 5: 5; LII 50: 25: 12: 10: 6: 5; LIII 60: 16: 12: 9: 5: 5. Wing: Hyaline, veins black; R4+5 and M1+2 parallel apically, CuAx ratio 0.3. Squama yellow with black setulae. Halter pale. Abdomen: Dark metallic green with pale gray pollinosity; setulae and setae on abdomen black. Male terminalia ( Fig. 1). Epandrium with angular projection posteriorly. Ventral projection of epandrium with acute end, far from distal margin of lateral epandrial lobe, width of projection about 0.7 as wide as lobe. Lateral epandrial lobe short and wide, with flat distal margin, bearing 2 setae. Surstylus almost straight, with base bent and apex tapering and slightly curved. Cercus short and wide, with moderately long setae. Hypandrium with banana-shaped lateral projection. Proximal potion of hypandrium with short projection. Postgonite with strip-like arms and anterior process, subequal in length, common base of arm and process with small sclerotized angular projection anteriorly. Female: Unknown.

Type material. HOLOTYPE ɗ, Guizhou: Anshun, Jiaozishan, 1400 m, 26º20’N, 105º57’E, 17.VII.1994, LM Wei, CG Wu and X Wei.

Etymology. From the Latin adunatus meaning “unite; ally”.

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 lateral epandrial lobe with flat distal margin bearing 2 setae and hypandrium with banana-shaped dorsolateral projection.

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.