Hercostomus plagiatus

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 : 425

Hercostomus plagiatus species group

Diagnosis. This diagnosis is based on males and females of the three included species (see detailed descriptions and illustrations of the then known species in Pollet (1993)).

Length: body about 4 mm, wing slightly shorter; body robust, dark metallic; head higher than wide; face moderately broad, gradually narrowed towards palpi; clypeus small, slightly bulging in both sexes, not reaching lower margin of eyes; palpus and proboscis small; vertical setae stronger than postverticals; antenna with simple antennomeres, located at upper quarter of head; scape setose dorsally, with pointed apicoventral process; pedicel with inner triangular projection; postpedicel rounded-triangular, with mid-dorsal stylus; arista-like stylus usually short-pubescent (but long-pubescent in H. golanensis ); pleural surface in front of posterior spiracle bare; mesonotum without distinct dark spot above notopleuron; 1 strong and 1–2 fine postpronotals, 1 strong posthumeral, 2–3 presutural, 1 sutural, 2 notopleural, 2 supraalar, 1 postalar bristles well developed; 6 pairs of strong dorsocentral bristles slightly decreasing in length anteriorly; acrostichals biserial, extending to scutellum (at least in H. golanensis ); anterior slope of mesonotum with dense hairs; propleuron with group of hairs above and 1 strong bristle below; all legs relatively short, with rather strong and long major bristles; hind coxa with 1 strong external seta at middle; one strong posterior to posteroventral preapical seta on mid femur; mid and hind femora moderately broad, with one preapical anterior bristle; all tibiae with strong dorsal bristles; fore tibia with anterodorsal comb-like row of setae distally; mid tibia with strong ventral bristles; hind tibia with only fine ventral setae; tarsi simple; hind basitarsus distinctly shorter than next tarsomere; wing regularly fumous; veins R4+5 and M1+2 usually straight and weakly convergent; abdominal sterna 3 and 4 strongly sclerotized; tergum 6 mostly concealed, bare; segment 7 short, bare, with distinct tergum and sternum; hypopygium large, without basiventral epandrial lobes; hypandrium mostly free, fused to epandrium at extreme base; basiventral epandrial seta situated near base of hypandrium; apicoventral epandrial lobes arising rather distally, far from base of hypandrium; anteroventral part of postgonite not developed; posterodorsal portion poorly developed, horn-like, slightly curved ventrally, swollen at base, with reduced lateral lobes; surstylus bilobate; female segment 8 with sternum and tergum fused into a narrow sclerite.