Euhybus tenuifemur sp. nov., 2024

Li, Meilin, Wang, Jingyu & Yang, Ding, 2024, The genus Euhybus Coquillett (Diptera: Hybotinae) from China, with descriptions of five new species, Zootaxa 5481 (5), pp. 520-530 : 525-526

9. Euhybus tenuifemur sp. nov.

( Fig. 3 )

Diagnosis. Arista short pubescent except apical 1/4 thin and bare. Legs entirely black. Hind femur weakly thickened, 1.2 times as thick as mid femur. Hind tibia with 2 short weak ad. Hypandrium apically somewhat narrowed and rounded.

Description. Male ( Fig. 3a ). Body length 3.2–3.4 mm, wing length 3.4–3.9 mm.

Head black with gray pollinosity. Eyes brownish yellow, with upper facets distinctly enlarged. Setae and setulae on head black; ocellar tubercle distinct, with 2 long anterior oc and 2 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 2.5 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. Setae and setulae on thorax black; setulae on scutum short and sparse; h absent, 2 long thick npl, irregularly biseriate acr, uniseriate dc and 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 entirely black. Setae and setulae on legs black except tibiae and tarsi with some dark brown setulae. Fore femur as thick as mid femur, with row of short setula-like pv slightly longer than femur thickness. Mid femur with row of long pv distinctly longer than femur thickness. Hind femur weakly thickened, 1.2 times as thick as mid femur, with 2 preapical ad, with one row of 9–10 av mostly spine-like (longest av slightly longer than femur thickness). Fore tibia distinctly thickened. Hind tibia distinctly thickened apically. Fore tibia apically with 3 slightly long thin setae. Mid tibia with 1 long thick ad at base and 1 long thin pd at extreme base, apically with 4 setae including 1 very long pv brownish. Hind tibia with 2 short weak ad (1 ad located near extreme base and 1 ad at middle), apically with 4 setae (1 pd long, brownish yellow). Fore tarsomere 1 apically with 4 mostly weak setae (only 1 av thick). Mid tarsomere 1 apically with 4 mostly weak setae (only 1 av thick). Hind tarsomere 1 with 1 long, spine-like ventral seta near base; apically with 1 long, spine-like av. Wing slightly infuscate, with well-developed anal lobe; costal cell not enlarged, costal vein with longer setae on basal 1/2; pterostigma long and brown, about 1/3 as long as cell r 1; veins dark brown. Squama dark brown with brownish yellow setulae. Halter brown.

Abdomen subshiny black with gray pollinosity, sternites 1–5 weakly sclerotized. Blackish setae and setulae on abdomen, except tergites 1–4 with dark yellow setulae and setae laterally and sternites 1–4 with dark yellow setulae. Male genitalia: Lepn narrower than repn, with inner margin slightly incised ( Fig. 3b ); lsur very wide, irregularly trifurcated, median process thin and acute in lateral view ( Fig. 3d ). Repn with inner margin weakly convex medially; rsur rather wide, apically with small incision nearly trapezoidal in lateral view ( Fig. 3c ). Hypandrium distinctly 1.4 times longer than wide, apically somewhat narrowed and obtuse ( Fig. 3g ).

Female. Unknown.

Type material. HOLOTYPE ♂, China: Xizang, Yadong, Renqinggang [27°41'41.57"N, 88°56'56.61"E, 3535 m], 2013.VII.18, Xiaoyan Liu ( CAU) . PARATYPE: same data as holotype (1 ♂, CAU) .

Distribution. China (Xizang).

Remarks. The new species is easily separated from other known species of the genus by the legs entirely black and hind femur rather thin.

Etymology. The specific name refers to the thin hind femur.

Figures

FIGURE 3. Euhybus tenuifemur. a. Male habitus, lateral view; b. Genitalia, dorsal view; c. Right surstylus, lateral view; d. Left surstylus, lateral view; e. Right surstylus, dorsal view; f. Left surstylus, dorsal view; g. Hypandrium, ventral view. Scale bar: 0.5 mm (a); 0.1 mm (b–g).