Systenus huanglianus, Lin & Zhang & Yang, 2023

Lin, Chen, Zhang, Chunmin & Yang, Ding, 2023, The genus Systenus Meigen, 1803 (Diptera: Dolichopodidae) from Yunnan, China, with descriptions of six new species, Zootaxa 5383 (2), pp. 153-166 : 161

5. Systenus huanglianus sp. nov.

( Figs 5 , 15–16 )

Diagnosis. Postpedicel rather long, 4.0 times longer than wide; arista 0.88 times as long as postpedicel. All coxae yellow, but mid coxa brownish yellow at base. R 4+5 and M 1 weakly convergent apically. Surstylus basally rather thick, apical long thin and finger-like. Male cercus strongly bent, basally slightly thick, apically with long thick ventral process.

Description. Male ( Fig. 5 ). Body length 3.0– 3.25 mm, wing length 2.5–3.0 mm.

Head metallic green with pale gray pollinosity. Frons metallic green with white gray pollinosity; face dark metallic green with dense silvery white pollinosity, narrower than width of postpedicel. Hairs and bristles on head black. 2 oc, 2 vt, 2 pvt. Antenna black; pedicel with blackish apical bristles; postpedicel rather long, 4.0 times longer than wide, basally rather thick, apically finger-like, and with dense dark brown pubescence; arista apical, 0.9 times as long as postpedicel, with very short dark brown pubescence ( Fig. 15 ). Proboscis short, brown with brown or dark brown hairs; palpus small, brown, with black hairs and 1 long black apical bristle.

Thorax metallic green with pale gray pollinosity, but pleura blackish except pteropleuron, hypopleuron black and anterior portion of sternopleuron. Hairs and bristles on thorax black; 6 dc, 12–13 irregularly paired acr; 2 strong npl, 1 strong sa, 2 strong pa; sc strong and long, lsc thin and short. Propleuron with 1 brownish yellow bristle on lower portion.

Legs mainly yellow to dark yellow; all coxae yellow, but mid coxa brownish yellow at base; mid and hind tibiae dark yellow at tip; all tarsi dark yellow to brown onwards from tarsomere 1. Hairs and bristles on legs mainly black; hairs on all coxae yellow, bristles brownish; hind coxa with 1 brown outer bristle at middle. Mid trochanter with 3 black bristles; hind trochanter with 1 black outer bristle at middle. Mid tibia with 1 ad, 2 pd and 2 apical bristles; hind tibia with 3 pd and 2 apical bristles. Mid and hind tarsomeres 1–4 each with 4 short apical bristles. Relative length of tibiae and five tarsomeres of legs LI 3.8: 1.7: 1.2: 0.8: 0.4: 0.6; LII 5.7: 2.8: 1.4: 1.2: 0.6: 0.5; LIII 6.1: 1.1: 3.0: 1.3: 0.7: 0.5.

Wing hyaline, somewhat brownish; veins dark brown, R 4+5 and M 1 weakly convergent apically; CuAx ratio 0.5. Squama yellow, with fan of pale white bristles. Halter pale yellow.

Abdomen dark metallic green with pale gray pollinosity, venter dark yellow. Hairs and bristles on abdomen black.

Male genitalia ( Fig. 16 ): epandrium distinctly longer than wide; epandrial lobe long, uniformly thick, apically with two minute denticles; surstylus basally rather thick, apically long finger-like. Cercus strongly bent, basally somewhat thick, apically with long thick finger-like ventral process. Hypandrium rather short, subconical. Phallus long and thin.

Female. Unknown.

Type material. HOLOTYPE ♂, China: Yunnan, Lvchun, Yakou, Shuikuxiafang [23°3’25.2”N, 102°46’37.71”E, 1779 m], collected by Malaise trap, 2019.IV.19–V.19, Liang Wang and Xin Li ( CAU) . PARATYPE: 1 ♂, same as holotype except, 2019.III.19–IV.19 ( CAU) .

Distribution. China (Yunnan).

Remarks. Systenus huanglianus sp. nov. is very similar to S. apicidigitatus sp. nov., but may be separated from the latter by the following features: antenna wholly dark brown; R 4+5 and M 1 weakly convergent apically; postpedicel rather long, 4.0 times longer than wide; arista 0.88 times as long as postpedicel; cercus basally somewhat thick.

Etymology. The specific name refers to the type locality Huanglianshan.

Figures

FIGURES 1–6. 1. Systenus apicidigitatus sp. nov.; 2. Systenus basiflavus sp. nov.; 3. Systenus digitatus sp. nov.; 4. Systenus flavilateralis sp. nov.; 5. Systenus huanglianus sp. nov.; 6. Systenus latimaculatus sp. nov. All male. Scale bar =1.0mm.

FIGURES 15–16. Systenus huanglianus sp. nov. (male). 15. Antenna; 16. Male genitalia, lateral view. Scale bar = 0.1mm. FIGURES 17–18. Systenus latimaculatus sp. nov. (male). 17. Antenna; 18. Male genitalia, lateral view. Scale bar = 0.1mm.