Euhybus nigritarsis, Wang, Ning, Li, Zhu & Yang, Ding, 2013

Wang, Ning, Li, Zhu & Yang, Ding, 2013, Euhybus newly recorded from Tibet with descriptions of two new species (Diptera: Empidoidea, Hybotinae), Zootaxa 3686 (3), pp. 373-380 : 377-378

2. Euhybus nigritarsis sp. nov.

( Figs 8, 9 , 10–14 )

Diagnosis. Antenna uniformly blackish. Wing grayish; R4+5 and M1 slightly convergent apically. Only mid tarsomeres 1–2 yellow. Hind femur 2 times as thick as mid femur, with 2 preapical setae and three rows of ventral setae; hind tibia with 3 weak ad. Costal cell and anal lobe enlarged.

Description. Male. Body length 3.4 mm, wing length 4.1 mm.

Head black with gray pollinosity. Eyes dark brownish yellow, with enlarged upper facets brownish yellow. Setae and setulae on head black; ocellar tubercle distinct, with 2 long oc, lacking short posterior setulae. Antenna blackish; pedicel with circlet of subapical setae; first flagellomere slightly longer than scape + pedicel, 3 times as long as wide, without dorsal setae; arista 3.5 times as long as first flagellomere, dark brown, short pubescent except apical 1/4 thin and bare. Proboscis brownish, distinctly shorter than head, slightly thickened and nearly obtuse apically; palpus blackish with 1 long seta at extreme tip.

Thorax black with gray pollinosity. Chaetotaxy on thorax black; setulae on scutum short and sparse; h absent, 2 long thick npl, acr in 6 irregular rows, uniseriate dc narrowly separated from acr, 1 long posteriormost dc, 1 prsc as long as dc, 1 long psa; scutellum with 8 marginal setulae (2 setulae between sc) and 2 long sc. Legs black with fore and mid tarsi blackish except mid tarsomeres 1–2 yellow. Setae and setulae on legs black except tibiae and tarsi with some dark brown setae. Fore femur as wide as mid femur, with row of short hair-like pv nearly as long as femur thickness. Mid femur with row of long pv distinctly longer than femur thickness. Hind femur 2 times as thick as mid femur, with 2 preapical ad, more or less with 3 rows of ventral spines (longest av nearly as long as femur thickness). Hind tibia thickened apically. Fore tibia apically with 1 long ad and 1 long pv. Mid tibia with 3 thick ad and 2 long hair-like pd, apically with 4 thick setae including 1 preapical ad and 1 long pv. Hind tibia with 3 weak ad (1 ad located near extreme base and 2 ad at middle), apically with pair of hair-like preapical dorsal seta and 1 somewhat thick av. Fore tarsomere 1 with 1 hair-like ad and 1 hair-like av. Mid tarsomere 1 with 1 thick anterior seta, 3 short av, 3 short pv and 1 long thick posterior seta; apically with 5 setae. Hind tarsomere 1 with 1 long spinelike av and 2–3 short spine-like pv; apically with 1 long spine-like av and 1 short spine-like pv. Wing ( Fig. 9 ) infuscate, with well developed anal lobe; costal cell enlarged, costal vein with longer setae basally; stigma long and dark brown, 1/3 as long as cell r1; veins dark brown, R4+5 and M1 slightly convergent apically. Squama dark brown with brownish yellow setulae. Halter dark brown.

Abdomen black with gray pollinosity. Abdominal setae and setulae black except tergites 1–5 with dark yellow setulae laterally and sternites 1–5 with dark yellow setulae.

Male genitalia ( Figs 10–14 ): Left epandrial lamella with inner margin distinctly incised; left surstylus relatively narrow, with two apical processes (one process weak, other process greatly elongated outwards and long finger-like). Right epandrial lamella with slightly incised inner margin; right surstylus rather wide with two thick apical processes (one process incised at middle and irregular in shape, other process obtuse). Hypandrium distinctly longer than wide, subapically with a transverse dorsal bridge, apically with three short processes. Phallus basally thick, but apically distinctly narrowed. Left and right postgonites narrow, strip-like.

Female. Unknown.

Type material. HOLOTYPE 3, Tibet, Medog (N 29.3281, E 95.3320), 80K, 1000 m, 23.vii.2012, Wenliang Li.

Distribution. China (Tibet).

Remarks. The new species is similar to E. nanlingensis Yang & Grootaert , but may be separated from the latter by the blackish first flagellomere, only mid tarsomeres 1–2 yellow and hind femur 2 times as thick as mid femur with 2 preapical ad. In nanlingensis , the first flagellomere is dark brownish yellow, tarsomeres 1–2 of all legs are dark yellow, and the hind femur is 1.5 times as thick as the mid femur with 3 preapical ad ( Yang & Grootaert 2007).

Etymology. The specific name refers to the black fore and mid tarsi.

Figures

FIGURE 9. Euhybus nigritarsis sp. nov., wing. Scale bar = 0.5 mm.

FIGURES 10 – 14. Euhybus nigritarsis sp. nov. 10. male genitalia, dorsal view; 11. right surstylus, lateral view; 12. left surstylus, lateral view; 13. hypandrium, ventral view; 14. hypandrium and phallic complex, dorsal view. Scale bar = 0.1 mm.