Xenopygina Frey, 1948

Mohrig, Werner & Kauschke, Ellen, 2016, New Black Fungus Gnats (Diptera, Sciaridae) of North America Part I. Genus Scatopsciara Edwards, 1927, Zootaxa 4150 (4), pp. 401-435 : 415-416

Subgenus Xenopygina Frey, 1948

Type species: Bradysia (Xenopygina) paradoxa Frey, 1948: 55 , 78, Fig. 52, plate 9. Literature: Hippa & Vilkamaa (1991): 115, 117; Menzel & Mohrig (2000): 486.

Species of the subgenus Xenopygina differ from those of the subgenus Scatopsciara s. str. mainly through the absence of an apical tooth. All other characteristics of the genus Scatopsciara are present in the subgenus Xenopygina as well. The subgenus is not as homogenous as Scatopsciara s. str., which is divided into two species groups only. Species of Xenopygina are divided here into three species groups, Scatopsciara paradoxa group, Sc. armata group and Sc. inesae group, newly introduced here.

1. Sc. paradoxa group includes the species abedabunae , adsilae , armigera , fratercula , hastata , paradoxa , robustior , subfratercula and vagula . The species group is characterized by the following characteristics: Body hairiness whitish or pale; tibial organ weakly developed (2–3 bristles on a weak, indistinct comb-like base); middle and hind tibiae with two well developed spurs, nearly equal in length; wings with short c (seldom longer than 1/2 w, often shorter); gonostylus with strong spines on the apex and in the middle of inner side, sometimes on a distinct process. Sc. fratercula and Sc. subfratercula have one distinct lobe-like process as base of two spines at the inner side, which mediates between two unique species Sc. hastata and Sc. paradoxa having a long process at inner side.

Species without process at inner side but with one or two bristles on the basal segment of the palpus only, might be misinterpreted as belonging to the genus Corynoptera . All species of the Corynoptera vagula group sensu Vilkamaa & Hippa (2006) belong in fact to species of the genus Scatopsciara (see also Mohrig et al. 2013: 195). Accordingly, the following species were combined new: Scatopsciara fera ( Mohrig & Heller, 1992) comb. n.; Scatopsciara nyxa Mohrig & Menzel, 1992 recomb. n..

2. Sc. armata group includes the species arenicola , alawae , praealawae and ventrospinula . The species group is characterized by a small tibial organ and a short c (1/2 w or shorter). Gonostylus are short and curved, the apex is slightly or strongly divided and the inner side has strong spines; apex of hind tibiae has two distinct, unequal spurs.

3. Sc. inesae group includes the species anobae, awanatae , chenoae , cucumeris , inesae , itumae , miakodae , praeawanatae , subawanatae , subitumae and submiakodae . This species group is characterized by brown body hairiness, two or more bristles on the basal segment of the palpus (rarely only one); wings with long c (longer ½ w); a broad, comb-like tibial organ; two distinct unequal spurs on the apex of middle and/or hind tibiae; gonostylus bulbous or slender, with 2–4 apical spines. Species resemble Bradysia in the shape of the gonostylus and a rather broad comb-like row of bristles of the tibial organ. Currently this species group is known for North America only.