Sepedon Latreille, 1804

Li, Zhu & Yang, Ding, 2017, Sepedon (Diptera: Sciomyzidae) species from China, with notes on taxonomy and distribution, Zootaxa 4254 (3), pp. 301-321 : 302

Genus Sepedon Latreille, 1804

Sepedon Latreille, 1804 . Nouv. Dict. Hist. nat. 24 (Tab. méth. Ins.): 196. Type species: Syrphus sphegeus Fabricius, 1775 (Monotypy) .

Diagnosis. Antennae long and porrect, pedicel slender, almost rod-like. In many species, frontal vitta and ptilinal suture absent. Orbital setae present or absent, ocellar setae absent. Usually one pair of apical scutellar setae present, rarely absent. Wings relatively narrow without reticulate pattern, with straight or arcuate posterior crossvein. Hind femur with short and strong ventral spines in both sexes.

Remarks. Sepedon is an easily distinguished genus with a large set of highly apomorphic characters. Some species have metallic luster, and in all species the median frontal vitta is replaced by a median longitudinal depression. Many setae are reduced, including the anterior orbital setae, the ocellar setae, and the basal scutellar setae, which are found in almost all other genera of Sciomyzidae and which are common to the ground plan of the family. In Sepedon lobifera , even the orbital setae and scutellar setae are absent. The male terminalia is unusually symmetrical, including the epandrium and hypandrium. Among the Sciomyzidae , one feature found only in some species of Sepedon is a sperm pump termed a “cochleate vesicle” ( Steyskal & Knutson, 1975).

Sepedon and related genera are so distinctive within the Sciomyzidae that various authors have considered them as a tribe, subfamily, or even family ( Knutson & Orth, 1984). Some Sepedon species are morphologically similar, and several species were often misidentified, as noted in some publications ( Steyskal, 1980; Rozkošný et al. 2010).