Hercostomus golanensis, Grichanov, Igor Ya., 2015

Grichanov, Igor Ya., 2015, Palaearctic species of the Hercostomus plagiatus group (Diptera: Dolichopodidae) with description of a new species from the Middle East, Zootaxa 3918 (3), pp. 424-432 : 427-429

Hercostomus golanensis sp. nov.

( Figs 1–8 )

Material. HOLOTYPE ♂, Israel: Golan (Heights), Qatzrin, 30.05.1981, F. Kaplan ( TAU). Paratype: 1 ♂, Israel: (Golan Heights), Tel Dan, 10.vii.1975, A. Freidberg ( TAU).

Diagnosis. Face under antenna inconspicuously wider than postpedicel height; postpedicel subtriangular, about as long as high; arista-like stylus long-pubescent, 2.2X longer than antennomeres combined; wing distinctly fumose; wing veins R4+5 and M1+2 parallel along most of their length, slightly convergent near wing apex; hypopygium with triangular cercus without scale-like setae; hypandrium smoothly curved, nearly reaching apex of apicoventral epandrial lobe; apicoventral epandrial lobe bearing 2 setae on its knob and 1 very long seta at base of stem.

Etymology. The species is named after the Golan Heights, where the types were collected.

Description. Male ( Fig. 1 ): Head: antenna mostly darkish yellow, distal half of postpedicel brown ( Fig. 2 ); postpedicel subtriangular, hardly longer than height; arista-like stylus mid-dorsal, 2.2X longer than antennomeres combined; distal segment of arista with all hairs at least 2X longer than basal diameter of stylus, sparse at apex; length ratio of scape to pedicel (inner view) to postpedicel to stylus (segments 1 and 2), 11/12/22 /23/49; frons black with greenish reflection, grey pollinose, nearly parallel-sided, slightly wider than height, with distinct dot-like depression in middle of lower part; eyes finely haired; face black, whitish-grey pollinose; ratio of height to width under antennae to width at clypeus, 0.40/0.20/0.15; clypeus small, bulging; palpus small, yellow, with few black hairs and 1 black seta; proboscis short and broad, yellow brown; lower postocular setae yellow, upper postoculars black. Thorax: all setae black; pronotum densely pubescent, with black hairs; mesonotum black with bluish reflection, weakly grey pollinose; 6 dorsocentral setae, 12–13 acrostichals, short, biserial, reaching scutellum; pleura entirely dark, with grey pruinosity, in front of posterior spiracle bare; metapleuron with vertical anteroventral row of about 6 short setae; scutellum mainly brownish-yellow, with black triangular spot on dorsum, with 2 strong medial setae and 2 fine lateral setae. Legs: almost entirely yellow, mid coxa with brown spot, 2–3 distal tarsomeres brown, hairs and setae black; all tarsi simple; foreleg with coxa bearing numerous black hairs anteriorly and 3 strong setae apically, fore femur with preapical posterior seta, fore tibia with 2 anterodorsal, 2 posterodorsal, 2–3 apical setae, with anterodorsal comb-like row of setae distally, no long apicoventral seta; midleg with coxa bearing some black hairs laterally and 2–3 strong setae apically, mid femur with 1 anterior and 1 posteroventral preapical strong seta, mid tibia with 3 anterodorsal, 2 posterodorsal, 1 anteroventral, 1 posteroventral and 5 apical bristles; hindleg with coxa bearing 1 strong seta at middle and few adjacent hairs, hind femur with 1 anterior preapical bristle at apical quarter, hind tibia with 3 anterodorsal, 3 posterodorsal, 3 apical bristles and 1 short ventral seta at middle; hind basitarsus with 2–3 ventral setae, distinctly shorter than next tarsomere. Femur, tibia and tarsomere (from first to fifth) length ratio (in mm): fore leg: 1.03/1.07/0.53/0.19/0.13/ 0.11/0.15, mid leg: 1.37/1.46/0.76/0.40/0.33/0.20/0.17, hind leg: 1.52/1.66/0.52/0.64/0.39/0.30/0.18. Wing ( Fig. 3 ): nearly 3 times longer than wide; membrane regularly fumous, veins brown; costa simple, with short black setae dorsally; R2+3, R4+5 and M1+2 almost straight; R4+5 and M1+2 subparallel; M joining costa at wing apex; ratio of costal section between R2+3 and R4+5 to that between R4+5 and M1+2: 0.38/0.23, distal part of CuA1 1.5X longer than dm-cu; anal vein distinct; anal angle obtuse; lower calypter yellow with black cilia; halter yellow. Abdomen: bluishgreenish-black and shiny, weakly pollinose, with black hairs and long marginal setae; 8th segment pear-like, black, with black cilia dorsally. Male genitalia ( Figs 4–8 ): epandrium black, rhomboid, as long as terga 3–5 combined; hypandrium mainly yellow, mostly free, fused to epandrium at extreme base, smoothly curved, nearly reaching apex of apicoventral epandrial lobe; phallus thin and long; basiventral epandrial lobes symmetrical, each lobe reduced to short seta at base of hypandrium; apicoventral epandrial lobe yellow, arising rather distally, far from base of hypandrium, prominent, with distinct apical expansion, bearing 2 setae on knob and 1 very long seta at base of stem; anteroventral part of postgonite not developed; posterodorsal portion poorly developed, horn-like, slightly curved ventrally, swollen at base, with reduced lateral lobes; surstylus bilobed, ventral lobe elongate-ovate, without dorsal hump, with short apical setae, dorsal lobe thin, expanded at base, slightly curved dorsally, with short apical setae and 1 strong and very long basodorsal seta; cercus yellow-brown in basal half, blackish distally, triangular, nearly 2/3rds epandrium length, nearly 2X as long as wide, with row of long black marginal setae and adjacent inner row of shorter light setae, without modified setae. Measurements: Body length 4.2 mm, antenna length 1.0 mm, wing length 3.8 mm, wing width 1.25 mm. Female: Unknown.

Figures

FIGURE 1. Habitus of Hercostomus golanensis sp. nov.

FIGURE 2. Antenna of Hercostomus golanensis sp. nov.

FIGURE 3. Wing of Hercostomus golanensis sp. nov.

FIGURE 4. Hypopygium of Hercostomus golanensis sp. nov., left lateral view.

FIGURE 5. Hypopygium of Hercostomus golanensis sp. nov., ventral view.

FIGURE 6. Hypopygium of Hercostomus golanensis sp. nov., ventral side, left lateral view.