Poecilosomella setosissima, Papp, 2010

Papp, L., 2010, Seven New Afrotropical Species Of Poecilosomella Duda (Diptera: Sphaeroceridae), Acta Zoologica Academiae Scientiarum Hungaricae 56 (1), pp. 9-41 : 35-38

Poecilosomella setosissima sp. n.

( Figs 64–68 , 72 )

Holotype male ( NMSA): [ Republic of South Africa] HOGSBACK NORTH OF ALICE, E CAPE PROVINCE 2–3 NOVEMBER 1964 B & P STUCKENBERG. Its left wing is prepared on a slide, its abdomen with genitalia prepared and is in a plastic microvial with glycerol.

Paratype female ( NMSA): SOUTH AFR: Cape Prov Hogsback 3226DB, 13–16.xii. 1985, J. & B. Londt Forest & forest margins .

Measurements in mm: body length 2.97 (holotype), 3.08 (paratype), wing length 2.42 (holotype), 2.51 (paratype), wing width 1.10 (holotype), 1.14 (paratype).

Body dark greyish brown, mesonotum with rich silvery pattern.

Three pairs of rather long interfrontals (only 2 pairs on paratype female). Anterior fronto-orbital much shorter than posterior pair (0.165 vs. 0.24 mm). No genal setae, i.e. anterior genal seta slightly shorter than the 1st peristomal behind vibrissa. Facial plate, antennal bases and lunule yellow (m) or brown (f). Gena reddish below eye and not broad (0.14 mm on holotype, 0.13 mm on paratype). Aristal cilia rather short (somewhat shorter than 0.02 mm).

Thoracic setae: 1 postpronotal, 2 notopleural (posterior pair on a swelling in supra-alar position), 1 true postalar, 1 presutural, 1 intra-alar (over wing base) and 1 intra-alar in prescutellar position; 2 pairs of strong dorsocentral setae. Prescutellar acrostichal pair of 0.29 mm (paratype). Anterior katepisternal seta 0.35 mm, posterior katepisternal 0.40 mm long (subequal on paratype female).

Wings ( Fig. 72 ) richly patterned. Wing membrane light brown, with darker brown diffuse spots, and marble brown spots. Second costal section shorter than third (0.55 mm vs. 0.64 mm on holotype) . Costa overruns apex of R by 0.015 mm. Sub-basal thorns of costa 0.24 mm and 0.19 mm long (holotype) . Apical section of R strongly thickened, almost perpendicular to costa, angle at base of apical section not edged, longitudinal part strongly curved medially. Apical half of R strongly curved up, arched, and ends farther from wing apex than vein M; vein M present almost to wing margin as a vein. Inter-crossvein section of M 0.25 mm, discal cell with a small upper triangular emargination, hind cross-vein 0.22 mm long (holotype) . Basal third of anal vein strongly thickened .

4+5

2+3

4+5

Femora and tibiae all dark brown, base of fore tibia as well as both ends of mid tibia dirty yellow. Tarsi mostly yellow, 5th tarsomeres, fore and hind basitarsus as well as 2nd mid and hind tarsomere brown. Male fore basitarsus with long hairs posteriorly and subventrally. Male fore femur and tibia with very long hairs ventrally and posteriorly. Mid femur with a row of long thick black setae in basal ¾, anteriorly subapically a large thorn present. Male mid tibia anteroventrally with medium-long black setae in apical ¾, posteroventrally with long hairs. Mid basitarsus with a complete though not straight row of short black setae, a posteroventral row on basal ¾ only, posteriorly with 2–3 unarranged rows of long hairs (no such hairs in female). Mid tibia of holotype with anterodorsal setae at 21/73 (long), 29/73 (very long), 52/73 (very long); long dorsal at 48/73 and an extremely long at 54/73; posterodorsals at 20/73 (long), 29/73 (very long), 44/73 (very long). Ventral hairs of hind femur and tibia also long, up to 0.2 mm.

(holotype male)

Abdomen broad (1.05 mm, length ca. 1.32 mm). Abdominal tergites dark brown with thick dark grey microtomentum, i.e. abdomen subshiny. Tergites 1 and 2 with a huge desclerotised and demelanised area, which almost reaches caudal margin and occupies almost half of tergite 2 medially. Longest marginal setae on tergite 5 0.29 mm. Sternites 2 to 5 transverse. Sternite 5 without any special setosity (armature), or sclerotised modifications medio-caudally. Sternite 6 with a – partly detached – plate in the medial area, which is almost horizontal (forming a cranial part of genital pouch). Sternite 8 at longest (sublaterally-subdorsally) not longer than sternite 6 and 7 combined, and continued ventrally. Epandrium slightly asymmetrical ( Fig. 64 ) and sparsely setose, longest (dorsal) pair only 0.19 mm long. Cercal lobes with thicker setae, other setulae thin. Subepandrial sclerite rather high with narrowed dorsal projections. Hypandrial arms rather thin and perpendicular to body axis (i.e. the possibly shortest), medial part 8with processes to postgonites) much shorter and thinner than phallapodeme. Surstylus ( Figs 65–66 ) composed of a shorter simple setose cranial and an intricate slightly trifid caudal lobe (one of the latter bears the blunt apical tooth). Some long setae on surstylus sub-basally, its setae on medial part not long but thick. Postgonite ( Figs 67–68 ) L-shaped; its longer vertical part ends in a swelling with short blunt pegs, apical (more horizontal) part covered with longer light hairs, better seen in ventral view. Basiphallus compact, a smaller ventral less sclerotised part with numerous blunt pegs. Threadlike process of distiphallus is broken on holotype but probably long. Phallapodeme 0.50 mm, broad based and rather high subapically.

Female cerci with medium-long dorsal and apical hairs (0.12–0.15 mm).

Etymology. Its specific epithet ‘setosissima’ [‘the most setose one’] refers to the unusually setose legs and the very strong body setosity of the new species.

I have not found a close relative of P. setosissima sp. n. among the Afrotropical species. This new species is characterised by its strong setosity of body and legs, richly patterned wing and by details of male genitalia. Cercal part of the epandrial complex covered by long hairs, surstylus long (high) with a shorter simple setose cranial and an intricate slightly trifid caudal lobe ( Figs 65–66 ); postgonite of peculiar shape ( Figs 67–68 ).

Figures

Figs 64–68. Poecilosomella setosissima sp. n., holotype male, genitalia. 64 = epandrium with cerci and subepandrial sclerite, caudal view,65 = surstylus in broadest extension (a sublateral view), 66 = apex of caudal lobe of surstylus, caudal view, 67 = postgonite and basiphallus, lateral view, 68 = post- gonite, ventral (!) view. Scales: 0.2 mm for Figs 64–65, 0.1 mm for Figs 66–68

Figs 69–72. Wings of Poecilosomella spp. n. 69 = P. additionalis sp. n. (paratype female); 70 = P. duploseriata sp. n. (paratype male), 71 = P. setimanus sp. n. (holotype male); 72 = P. setosissima sp. n.