Poecilosomella spinicauda, Papp, 2002

Papp, L., 2002, Eighteen New Oriental Species Of Poecilosomella Duda (Diptera: Sphaeroceridae), Acta Zoologica Academiae Scientiarum Hungaricae 48 (2), pp. 107-156 : 141-143

Poecilosomella spinicauda sp. n.

( Figs 54–57 )

Holotype male ( ROM): PHILIPPINES, Negros , Oriental: Cuernos de Negros, 7 km W. Valencia, 29 JUN – 8 JUL 1987. DC Darling, E. Mayordo. ROM 873061 – 1 ° rainforest edge, 700 m, Malaise w/pans.

Paratypes: 1 male, 6 females (1 male, 2 females in HNHM): same as for holotype ; 1 male, 2 females ( ROM, 1 female HNHM): ibid., 15–21 JUL 1987, ROM 873063 – 09° 17’N x 123° 15’E ; 1 male, 1 female ( ROM): ibid., 700 m, 5–13 MAY 1988, ROM 873102 , DC Darling – Malaise w/pans, 1° forest edge ; 1 male, 2 females ( NMNH, HNHM): TONGA: Vavau, Neiafu , 0– 100 m ., III–74, N.L.H. Krauss; 1 male ( NMNH): “Society Is., Tahiti, Paea, Robinson’s Place, K.M. 26, March 27, 1261 " .

Measurements in mm: body length 1.80 (holotype), 1.80–2.12 (paratype males), 1.84–2.20 (paratype females), wing length 1.72 (holotype), 1.72 – 2.13 (paratypes), wing width 0.89 (holotype), 0.88 – 1.07 (paratypes).

Facial plate more convex. At least face or frons reddish or even lighter. Two pairs of long and thick orbital setae. Apical part of first flagellomere markedly lighter than rest of flagellomere, also in females. Arista rather short, only 0.55 mm on holotype. Arista with medium long cilia only (ca. 0.022mm), cilia on flagellomere shorter. Two or three pairs of medium long ifr. Genal seta rather long, 0.17mm on holotype.

Scutellum normal, i.e. slightly shorter than broad: 0.41 mm long, 0.60 mm broad basally, apical scutellar 0.67 mm (Tahiti paratype male). Katepisternals both large, subequal in size.

Wings broad, only about twice longer than wide, without vein appendage on R 2+3. Costal hairs shorter. Second costal section 0.55 mm, third section 0.57 mm (Tahiti paratype). Vein R 4+5 more strongly bent towards the costa, i.e. apical part not straight, consequently medial part less curved (basal half slightly S-shaped).

Male fore tibia and basitarsus (possibly other tarsomeres) posteriorly, or ventrally to posteriorly, with long hairs (longer than their diameter at bases of hairs). Male mid tibia not curved inwards and not flattened. Male mid tibia ventrally without long hairs, ventroapical seta more or less strong. Fore tarsomeres at least partly yellow, but not white. A yellow ring present on the middle of fore tibia.

Male tergite 5 normal, with the usual marginal bristles. Epandrium with long setae. Lateral part of subepandrial sclerite ( Figs 56–57 ) with 4 pairs of thick black slightly inclinate setae, more medially a patch of medially directed, thicker, almost straight, hairs. Surstylus ( Fig. 54 ) medially with a thick but acute thorn and several strong setae, lateral lobe rather broad, its medial base with a large black dentiform (slightly bidentate) thorn (process). Postgonite ( Fig. 55 ) comparatively short, strongly curved, rather broad medially, apical half bears dense short hairs.

Female terminalia not studied.

Distribution: Philippines, Tonga, Tahiti; probably widespread in the Pacific Oceanian region. view. Scales: 0.2 mm for Figs 54–56 , 0.1 mm for Fig. 57

The relationships of P. spinicauda sp. n. are unclear to me at present. It is possible that it is not far from the P. varians species group. The thick setae of subepandrial sclerite do not seem to be homologous with those of P. sabahi . For instance, their bases are so close to epandrium ( Fig. 56 ) that in some views the thick setae seem to emerge from the apex of the epandrium itself. Apical part of first flagellomere markedly lighter than rest of flagellomere, in both males and females, and this character can be used to reliably identify females of this species.

Figures

Figs 54–57. Poecilosomella spinicauda sp. n., paratype male, genitalia. 54 = surstylus, outer widest (subcaudal) view, 55 = postgonite, lateral view, 56 = ventral part of epandrium, lateral view (as if thorns on subepandrial sclerite were on epandrium), 57 = left half of subepandrial sclerite, subventral