Lonchaea stelviana
Differential diagnosis: Within the European fauna, the combination of bare eyes, multiserial anterior genal setulae and a single stigmatical setae indicate that this species belongs to the Lonchaea tarsata Fallén, 1820 group of species which also contains L. longitarsis MacGowan, 2008 and L. setifemora MacGowan, 2009. L. stelviana is easily distinguished from these species by the lack of long posterodorsal setulae on the hind femora. L. stelviana is also distinguished from L. tarsata by differences in the male genitalia most notable by its large, rectangular cerci and two segmented aedeagus.
The single setulae on the left orbital plate and the setulae present next to the stigmatical setae on the left side do perhaps indicate that this species has some relationship to the L. patens Collin, 1953 group. Although members of this group do have a two segmented aedeagus and surstyli with a pointed posteroventral process the lack of a setulose scutellar disc and distinctive male genitalia serve to distinguish L, stelviana.
Description : Male : Head : Eyes bare. Frons narrowing slightly from level of ocellar triangle to antennal bases at which point it is half the width of an eye, dull black with long and numerous frontal and interfrontal setulae some of which are 75% the length of the orbital setae. Orbital plate shining black, bare on right side but bearing one small setulae on the right orbital plate. Lunule and face matt black, parafacials shining black. Anterior genal setulae rather spread over the width of the genae but with a row of four very small setulae at extreme anterior along the mouth edge. Antennal 1st flagellomere twice as long as it is deep, entirelly black, arista brownish basally with microscopic setulae.
Thorax : disc subshining black, covered with long setulae which are as long as the orbital setae. Prosternum bare. All pleural setulae long, setae on anepisternum not distinguishable form the other setulae on the sclerite. Katepisternum with one long thin setae on dorsal margin, with one setulae lying posterior to it. One propleural and one stigmatical setae on the left side, right side with an additional hair-like stigmatical beside the setae. Prothorax bare. Scutellum shining black and bare on disc, margin between the lateral and apical setae with two setulae on one side and one on the other, three setulae between the apical setae. Calypteres greyish with a dark margin and fringe. Wings clear with yellow veins, intercostal space four times length of crossvein r-m. Wing length 4.0 mm.
Abdomen: when seen from above rather circular in outline, tergites shining black laterally, sternite 1 bare. Legs with basal tarsomeres brownish yellow, others becoming darker apically.
Male genitalia, (Figs. 2 - 4) in lateral view epandrium rather rectangular, slightly wider than high, bearing a few setulae along the ventral and posterior margins. Cerci large and roughly rectangular, more than half the depth of the epandrium, chitinised dorsally and posteriorly and bearing a few setulae on their surface and along the posterior and dorsal margins. Surstyli projecting beyond the shell of the epandrium posterior ventrally as a rather triangular, sharp pointed process. In ventral view inner margin of surstyli along their length bearing a close row of relatively long setulae, margins slightly scalloped posteroventrally. Aedeagus two segmented, basal portion a broad J-shape, apical portion sinuous.