Syneches basalis, Liu, Xiaoyan, Zhang, Lili & Yang, Ding, 2012

Liu, Xiaoyan, Zhang, Lili & Yang, Ding, 2012, Two new species of Syneches belonging to S. signatus species-group from Vietnam (Diptera: Empidoidea, Hybotinae), Zootaxa 3300, pp. 55-61 : 58-61

2. Syneches basalis sp. nov.

(Figs. 6, 7, 8–10)

Diagnosis. Thorax brownish yellow. Hind leg yellow except basal 0.5 and extreme tip of femur dark brown, apical 0.33 of tibia brown, and tarsomere 5 dark brown. Pterostigma elongate, about 0.33 as long as cell R1. R4+5 and M1 distinctly convergent subapically.

Description. Male (Fig. 6). Body length 6.1 mm, wing length 6.2 mm.

Head blackish brown with gray pollen. Eyes contiguous on frons, brownish with enlarged upper facets dark yellow. Hairs and bristles on head black. Ocellar tubercle distinct with 2 oc and 2 posterior hairs. Antenna dark yellow except first flagellomere blackish with dark yellow base; first flagellomere about 2X longer than wide, with 1 dorsal bristle; arista dark brown, very long (about 3X as long as three basal antennal segments), bare. Proboscis nearly as long as head, brownish yellow; palpus dark yellow with black hairs, 1 ventral bristle near base and 1 ventral bristle at extreme tip.

6. Syneches basalis sp. nov. (male). Adult. Scale bar = 1 mm.

Thorax brownish yellow with gray pollen; mesonotum dark brownish yellow. Hairs and bristles on thorax black. Hairs on mesonotum short, but mid-posterior area with some longer hairs; h absent; 6 irregularly seriated acr short and hair-like, 1 npl, 1 psa; scutellum with 18 marginal hairs and bristles. Fore and mid legs yellow except tarsomere 5 brown; hind leg yellow except basal 0.5 and extreme tip of femur dark brown, apical 0.33 of tibia brown, tarsomere 5 dark brown. Hind femur distinctly thickened, 2.6X as wide as hind tibia. Hairs and bristles on legs black except several ventral bristles and apicoventral bristles on mid tibia brownish yellow. Fore femur with row of long av and pv slightly longer than femur thickness; mid femur with row of very long av and pv distinctly longer than femur thickness. Mid tibia with 1 very long black ad near base and 1 very long brownish yellow av near middle; apically with 5–6 strong bristles mostly brownish yellow, of which 1 av is long and 1 pv is very long. Hind femur with 2 ad apically, one row of 11 strong av on tubercles (of which basal tubercles weak and 6 apical tubercles long, finger-like); apically with 3 short v on tubercles; hind tibia weakly curved. Wing ( Fig. 7 ) slightly tinged grayish; long pterostigma brown; veins dark brown; R4+5 and M1 distinctly convergent apically. Halter dark brown with yellow base and knob brownish.

Abdomen dark brown with gray pollen except tergite 1 and lateral portion of tergite 2 brownish yellow, sternites 1–2 yellow. Hairs and bristles on abdomen black.

Male genitalia ( Figs. 8–10 ). Epandrium ( Fig. 9 ) distinctly longer than wide and with trapezoid mid-basal incision in dorsal view; surstylus ( Fig. 8 ) with short, dorsal finger-like process, ventral process short, wide and obtuse apically in lateral view; hypandrium ( Fig. 10 ) distinctly longer than wide, apically slightly widened at tip and with V-shaped middle incision; phallus ( Fig. 10 ) somewhat acute apically, subapically with short obtuse lateral process; postgonite not clearly identified.

Female. Unknown.

Type material. HOLOTYPE ɗ (in alcohol), VIETNAM, Dongnai, Tanphu, Namcattien, Cattien National Park, 11°38'12.89''N 107°27'24.99''E, 2011. VII.3, Guoquan Wang ( CAU). The specimen was collected from tropical forest.

Remarks. The species is similar to Syneches xishuangbannaensis (Yang et Yang) from Yunnan of China, but can be separated from the latter by the hind leg yellow except basal 0.5 of femur dark brown, apical 0.33 of tibia brown and tarsomere 5 dark brown, and phallus somewhat cross-shaped apically. In xishuangbannaensis , the hind leg is brown except the coxa and tarsus yellow with tarsomere 5 brown, and the phallus is nearly circular apically (Yang & Yang 1994).

A female specimen ( Vietnam: Thua Thien-Hue: Bach Ma Natl. Park, Pheasant trail, 500 m, 2–13.vi.2001, 16°13'41.2''N 107°51'20.5''E, D.C. Darling & B. Hubley, trop. evergreen for., MT) in the Canadian National Collection is very similar to S. basalis , except the hind tibia is entirely yellow (B. Sinclair, pers. comm. 2012). A careful assessment of leg chaetotaxy is required to determine whether it is conspecific with the male holotype.

Etymology. The specific name refers to the basal half of the hind femur dark brown.

Figures

FIGURE 7. Syneches basalis sp. nov. (male). Wing. Scale bar 1 mm.

FIGURES 8 – 10. Syneches basalis sp. nov. (male). 8. Epandrium and cercus, lateral view; 9. Epandrium and cerci, dorsal view; 10. Hypandrium and phallus, ventral view. Scale bar 0.1 mm.