Chrysotus apicicaudatus, 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 : 8-10

4. Chrysotus apicicaudatus sp. nov.

( Fig. 4 )

Diagnosis. Eyes contiguous on face. Postocular setae black. Proboscis blackish brown, palpus blackish brown. All coxae black, femora black, base of tibiae brown. Squama pale with brown setulae. Halter pale. Male terminalia with ventral projection of epandrium prominent. Surstylus thin and long, clearly curved. Postgonite with tongue-shaped anterior process.

Description. Male: Body length 2.2 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 black. Antenna black; first flagellomere broken off. Proboscis blackish brown with black setulae; palpus blackish brown with 1 black apical seta. Thorax: Dark metallic green with pale gray pollinosity. Setulae and setae on thorax black; 6 strong dc, 6 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: (fore tarsomeres 3-5 and midleg lost) Yellow, all coxae and trochanters black, femora black; base of tibiae brown; fore tarsus from tip of tarsomere 1 onwards brown to blackish brown, hind tarsus black. Setulae and setae on legs black. Mid and hind coxae each with 1 outer seta. Fore femur with 3 pv apically, hind femur with 3 av apically. Fore tibia with 1 ad, apically with 3 short setae; hind tibia with 2 ad and 4 pd, apically with 4 setae. Relative lengths of tibia and 5 tarsomeres of legs LI 40: 20: 10:?:?:?; LII?:?:?:?:?:?; LIII 60: 17: 12: 10: 5.5: 5. Wing: Hyaline, veins brown; R4+5 and M1+2 parallel apically, CuAx ratio 0.3. Squama pale with brown setulae. Halter pale. Abdomen: (left surstylus lost) Dark metallic green with pale gray pollinosity; setulae and setae on abdomen black. Male terminalia ( Fig. 4 ). Epandrium with angular projection posteriorly. Ventral projection of epandrium prominent, with acute end slightly withdrawn from level of waved distal margin of lateral epandrial lobe. Lateral epandrial lobe shorter and wider, bearing 2 short and weak setae. Surstylus thin and long, clearly curved. Cercus wide and short, with strong setae. Hypandrium with ventral process pointed apically. Proximal portion of hypandrium with short process. Postgonite with strip-like arms and tongueshaped anterior process, where former shorter than latter. Otherwise, anterior process with triangular process anteriorly. Female: Body length 2.4 mm, wing length 2.5 mm. Similar to male, except face wide. Mid tibia with 3 ad and 1 pd, hind tibia with 2 ad and 6 pd (upper 3 pd somewhat weak). Relative lengths of tibia and 5 tarsomeres of legs LI 62: 38: 17: 10:10: 10; LII 90: 50: 20: 13: 9: 9; LIII 116: 30: 25: 15: 10: 10. Terminalia ( Figs. 4 A-B). Ventral viewed: Tg6–7 with deep inverted U-shaped incisions; Tg8 divided into pair of rod-like sclerites, each with large triangular sclerite on inner margin mesally, weakly sclerotized; Tg9 retrogressive; acantophorites (Tg10) divided into two sclerites, each on dorsal surface with crest 6 acute spines; posterior margin of St5 with shallow U-shaped incision; St6 rectangular, with length shorter than width, anterior margin with shallow U-shaped incision; St7 rectangular, weakly sclerotized, with length longer than width, anterior margin with shallow inverted U-shaped incisions; St8 divided into pair of rod-like sclerites and connected anteriorly by sclerotized bridge; St10 with finger-like apex, setose. In profile: both Tg8 and St8 widely separated from each other basally; St8 with fork-like end; St9 divided into 2 bent sclerites, both acute apically, with setulae; St10 curved stick-shape, with group of setae apically; cercus longer, diamond-like, proximal end with seta ventrally.

Type material. HOLOTYPE ɗ, Guizhou: Daozhen, Dashahe, 1400 m, 16.V.2006, ZH Yang. PARATYPES: 2 Ψ, same as holotype.

Etymology. From Latin apic “pointed end” and caudatus “comb”, meaning pointed end of abdomen (epandrium).

Remarks. According to the key of Negrobov et al. (2000), the new species will run to C. nudisetus Negrobov et Maslova, 1995 but can be separated from the latter by ventral projection of epandrium prominent and slightly withdrawn from level of waved distal margin of lateral epandrial lobe; hypandrium with only a 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 4. Chrysotus apicicaudatus sp. nov., (A) male terminalia, right lateral view; B-C. female terminalia; (B) dorsal view; C. lateral view).