Poecilosomella occulta, Papp, 2010

Papp, L., 2010, Seven New Afrotropical Species Of Poecilosomella Duda (Diptera: Sphaeroceridae), Acta Zoologica Academiae Scientiarum Hungaricae 56 (1), pp. 9-41 : 21

Poecilosomella occulta sp. n.

( Figs 27–32 )

Holotype male ( HNHM): RSA [Republic of South Africa], Eastern Cape Prov., beside Bloukrans River , Jan 14, 2007, GPS17, S33°57’20.9” E23°38’18.8”, 28 m, leg. L. PAPP & M. FÖLDVÁRI.

Paratype male ( HNHM): ibid., KwaZulu Natal, N Drakensberg, Rainbow Gorge, Jan 26–28, GPS29, S28°57’36.7” E29°13’33.6”, 1529 m, No.39 .

Measurements in mm: body length 2.37 (holotype), 2.31–2.42 (paratypes), wing length 2.04 (holotype), 1.85–2.07 (paratypes), wing width 0.90 (holotype), 0.79–0.92 (paratypes).

Head all dark brown, at most frons reddish anteriorly. Facial plate brown and shiny. Antennae dark, only pedicel somewhat dark reddish. Aristal cilia short, not longer than 0.015 mm. Genal seta strong.

Anterior katepisternal seta minute.

Wing mostly clear, membrane light brownish, only a darker brown spot present around conjunction of R 1 and costa, down to the R fork and almost to vein M. A dark brown spot around curved apical section of R 2 +3 present. Veins ochre, dark brown on the areas of spots. Second costal section 0.505, third section 0.495, ratio 1.02 (holotype, but rather similar also on paratypes). Apical part of vein R 2 +3 strongly but not angled curved, without any vein appendage, or, with a short vein appendage (3 paratypes). Inter-crossvein section of M shorter than hind crossvein and both are white .

Legs brown, both ends of tibiae dirty (brownish) yellow; a broad ring of this colour present on middle of each tibia. Anterodorsals on mid tibia (holotype): 11/55 (small), 13/55 (short), 20/55 (long and thick), 38/55 (long and thick). A very long a thick subdorsal seta at 47/55. Posterodorsals: 18/55 (small), 21/, 25/, 31/, 38/55 (all short), 43/55 (medium long). Anteroventral and posteroventral setal rows of mid basitarsus not strong (i.e. not characteristic). Ventro-apical of mid tibia weak, slightly incurved. Tarsi dirty yellow, tarsomeres 4 and 5 brown.

Male genitalia ( Figs 27–32 ) distinctive. Cerci (pseudocerci) with a pair of not too high (0.01–0.015 mm) and comparatively distant ridges, which do not overrun caudal margin. Medial part of the cercal area with fine hairs only ( Fig. 27 ). Dorsal lobes of subepandrial sclerite not too high. Surstylus ( Figs 28–29 ) with small medial (membranous) lobe, proximal part without numerous long setae (characteristic in P. kittenbergeri ), cranial lobe with long setae. Thorn on apex of caudal lobe ( Fig. 29 ) rather long. Postgonite ( Fig. 30 ) with large broad apical half and rather short and thin proximal part. Hairs on apical part laterally are rather short. Basiphallus ( Figs 31–32 ) much curved, setae on ventral part not peg-like but rather long and sharp.

Female not known (at least I was not confident in selecting any female as a paratype).

Poecilosomella occulta sp. n., as any other member of the P. longecostata species group, is to be identified by an analysis of the male genitalia.

Etymology. The specific epithet of this new species refers to the cryptic appearance, since it is very similar to its related species, except for male genitalia (‘occultus’ = hidden, concealed).

Figures

Figs 27–32. Poecilosomella occulta sp. n., paratype male, genitalia. 27 = ventral part of epandrium with cerci and subepandrial sclerite, caudal view, 28 = surstylus in broadest extension, 29 = same, apical part in higher magnification, 30 = postgonite in broadest (sublateral) view, 31 = basiphallus of the holotype, lateral view, 32 = basiphallus of a paratype. Scales: 0.2 mm for Figs 27–28, 0.1 mm for Figs 29–32