Euhybus furcatus 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 : 522-524

2. Euhybus furcatus sp. nov.

( Fig. 2 )

Diagnosis. Legs black except extreme tip of fore tibia brownish yellow and entire mid tibia dark yellow; tarsi blackish except fore and mid tarsomeres 1–2 dark yellow, hind tarsomere 1 dark brownish yellow. Rsur trifurcated, median process finger-like with very long setae.

Description. Male ( Fig. 2a ). Body length 3.2 mm, wing length 3.6 mm.

Head black with pale gray pollinosity. Eyes dark yellow with upper facets indistinctly enlarged. Setae and setulae on head black; ocellar tubercle weak, with 2 long anterior oc and 2 short posterior setulae. Antenna blackish; first flagellomere slightly longer than scape + pedicel, about 3 times longer than wide, without dorsal setae; arista 3.7 times as long as first flagellomere, dark brown, bare, with apical 1/4 thin. Proboscis brownish, distinctly shorter than head, thickened, nearly obtuse apically; palpus dark brown with 1 long, curved seta at extreme tip.

Thorax black with pale gray pollinosity except mesonotum shiny black with narrow anterior and wide posterior portion pollinose. Setae and setulae on thorax black; h absent, 2 long strong npl, setula-like acr biseriate, setula-like dc uniseriate except only 1 posteriormost dc slightly long, 1 psa, scutellum with 6 marginal setulae and 2 long sc. Legs black except extreme tip of fore tibia brownish yellow and entire mid tibia dark yellow; tarsi blackish except fore and mid tarsomeres 1–2 dark yellow, hind tarsomere 1 dark brownish yellow. Setae and setulae on legs black. Fore femur nearly as thick as mid femur; hind femur 2 times as thick as mid femur, with 3 long thin preapical ad. Hind femur with row of 13 mostly long av spines, basal portion with row of 3 mostly long pv spines. Fore tibia weakly thickened, apically with 3–4 thin setae (1 posterior seta very long); mid tibia with 1 long thin ad, apically with 4 thin setae (1 av and 1 pv very long). Hind tibia distinctly thickened apically, without dorsal setae; apically with 1 thin av and 1 long strong preapical ad. Fore and mid tarsomere 1 with some long setulae. Mid tarsomere 1 with 1 long strong pv at base. Hind tarsomere 1 with 1 spine-like av at base. Wing lightly infuscate; costal vein with longer setae on basal 2/3; dark brown pterostigma short and rounded (about 1/6 as long as cell r 1, not filling apex of cell r 1); veins dark brown. Squama brown with brownish setulae. Halter dark brown.

Abdomen subshiny black with thin gray pollinosity; hypopygium distinctly swollen, broader than abdomen. Blackish setae and setulae on abdomen, except tergites 1–3 with dark yellow setae and setulae and sternites 1–5 with dark yellow setulae. Male genitalia: Lepn slightly narrower than repn, basally with inner margin weakly incised ( Fig. 2b ); lsur very wide, bifurcated with U-shaped median incision apically in lateral view ( Fig. 2d ). Repn apically with slightly incised inner margin; rsur trifurcated, median process finger-like with very long setae in lateral view ( Fig. 2c ). Hypandrium 1.6 times longer than wide, with slightly incised and oblique apical margin bearing short setulae ( Fig. 2g ).

Female. Unknown.

Type material. HOLOTYPE ♂, China: Xizang, Nielamu, Zhangmu [27°59'18.04"N, 85°58'58.00"E, 2893 m], 2013.VII.27, Xiaoyan Liu ( CAU).

Distribution. China (Xizang).

Remarks. The new species is somewhat similar to E. taiwanensis from Taiwan, but may be separated from the latter by the mid tibia with 1 ad, and lepn without process on inner margin. In E. taiwanensis , the mid tibia has 2 ad, and lepn has one spherical process on inner margin ( Liu et al. 2011).

Etymology. The specific name refers to the rsur trifurcated.

Figures

FIGURE 2. Euhybus furcatus. 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).