Hebecnema Schnabl, 1889

Michelsen, Verner, 2019, Macaronesian Muscidae (Diptera). I. The genus Hebecnema Schnabl with description of a new Canarian endemic species and a review of the European fauna, Zootaxa 4706 (2), pp. 332-348 : 333

Genus Hebecnema Schnabl

Diagnosis. Small muscids, wing length not exceeding 6.5 mm. Abdomen without paired dark spots on tergites. Arista plumose. Female frons with two fronto-orbital setae and without a pair of setae on frontal vitta. Dorsocentral setae 2+4 (2+ 3 in some extralimital species). Prealar seta absent. Prosternum, notopleuron, anepimeron, katepimeron and meron without setulae. Wing without setulae on Rs node (setulae present ventrally or on both sides of Rs node in some extralimital species). Distal section of vein M straight. Hind tibia without a submedian pd seta. Female terminalia (ovipositor) of the “ Mydaea type ”: short and thick, sternite VIII pieces with spine-like setae, cerci flattened and without projecting tips.

Description. The following description is adjusted to the European species: Small muscids (wing length 3.8‒ 6.5 mm) with wholly dark head and body; appendages also dark except femora and tibiae often to varying degree coloured ochre brown to yellow. Male and sometime female wing with dark clouding of varying intensity; cross-veins r‒m and dm‒m not specifically shadowed. Abdomen without paired dark spots on tergites II‒IV. Arista plumose, longest branches same length or longer than width of postpedicel. Female frons with two fronto-orbital setae, both reclinate; frontal vitta without interfrontal setae. Prealar seta absent. Presutural acrostichal setae 3‒5 pairs slightly to moderately stronger than mesonotal ground setulae, standing as wide or wider apart than their distance to adjacent rows of dorsocentral setae; area between presutural acrostichal rows occupied by setulae in 2‒4 irregular rows; area between acrostichal and dorsocentral setal rows bare. Dorsocentral setae 2+4. Notopleuron without setulae in addition to usual two setae. Prosternum, anepimeron, katepimeron and meron bare. Vein C setulose ventrally, dorsally bare or setulose on distal half. Rs node without dorsal or ventral setulae. Distal section of vein M straight. Leg chaetotaxy sparse and similar in both sexes: Fore tibia without p seta; mid tibia with 2 p setae; hind tibia with 1‒3 av and 1(‒2) ad setae, without submedian pd seta or setae on p‒pv surface; hind coxa without setulae on inner posterior margin. Sternite I bare, rarely with a few fine setae. Male terminalia: shape and chaetotaxy of sternite V, surstyli and cerci are usually species characteristic, whereas interspecific differences in the pre- and postgonites and phallus are very subtle. Female terminalia: ovipositor short and thick, curved upwards and distally somewhat laterally compressed; sternite VIII pieces with 4 or 7 spine-like seta(e); epiproct shortened; cerci short, subvertical, without projecting tips; hypoproct convex, with a cluster of fine up-curved setulae.