Stenus cirriostentans, Puthz, 2012

Puthz, V., 2012, On the Stenus LATREILLE 1797 from Taiwan with non-spotted elytra (Coleoptera, Staphylinidae) (327 Contribution to the Knowledge of Steninae), Linzer biologische Beiträge 44 (2), pp. 1431-1475 : 1434-1435

Stenus cirriostentans nov.sp. ( Fig. 27 )

Type material: Holotype () and 3, 3 - paratypes: Taiwan: Nantou Hsien: near Tsuifeng , 2200m, 22.VIII.1976, Y. Shibata. Paratypes: 4, 11: same locality as HT, 29.VII. and 20.VIII., 21.VIII.1976, idem.- HT and PTT in coll. Shibata (Tokyo), PTT also in cP.

Description: Apterous, black, forebody moderately shiny, abdomen brilliant, fore-body coarsely punctate, punctation of pronotum and elytra very shortly coalescent, anterior punctation of abdomen coarse and dense, posterior punctation fine and sparse; pubescence long, erect on abdomen. Antennae yellowish brown, club infuscate. Maxillary palpi yellowish, segment 3 infuscate. Legs yellowish brown. Clypeus black, labrum blackish brown, sparsely pubescent. Abdominal segment 3 with very narrow paratergites, the following segments only with a very fine line laterally. Tarsal segment 4 simple.

Length: 2.6-3.1 mm (fore-body: 1.3-1.5 mm).

PM of the HT: HW: 25.5; DE: 12; PW: 19; PL: 19; EW: 23; EL: 19; SL: 14.

Male: Metasternum slightly impressed, moderately coarsely and densely punctate, interstices very shallowly reticulate. Sternites 3-7 simple, sternite 7 medially more densely punctate than laterally; sternite 8 with a broad and shallow apical emargination (LS: ED= 53:3). Sternite 9 acute apicolaterally. Aedeagus (fig. 27), apical portion of median lobe broadly rounded, anterior margin of expulsion clasp acute on both sides; parameres nearly as long as the median lobe, with about 12 long apical setae.

Female: Sternite 8 broadly rounded posteriorly. Valvifer acute apicolaterally. Spermatheca about as in fig. 16 ( PUTHZ 2009): spermathecal duct with a coiled portion medially, a tiny collum, infundibulum slender, at least 4x as long as broad.

Head broader than elytra, frons moderately broad, longitudinal furrows distinct, median portion nearly as broad as each of the lateral portions, elevated, slightly exceeing the level of medial eye margins; punctation coarse and very dense on lateral portions, sparser on median portion, diameter of punctures about as large as apical cross section of antennal segment 2, interstices laterally much smaller than half the diameter of punctures, larger medially, sometimes larger than diameters of punctures. Antennae short, when reflexed extending to the posterior third of pronotum, penultimate segments about as long as broad. Pronotum as broad as long, broadest in anterior half, sides convex anteriorly, concave posteriorly with a broad longitudinal impression medially, a shallow transverse constriction near anterior margin and a shallow transverse impression in posterior half on each side; punctation coarser than on frons, very dense, very slightly coalescent, the median impression impunctate, diameter of punctures at least as large as apical cross section of antennal segment 2. Elytra sub-trapeziform, much narrower than head, about as long as broad, shoulders oblique, sides feebly convex, slightly narrowed behind, posterior margin broadly emarginate; sutural impression indistinct, humeral impression very shallow; punctation slightly coarser than on pronotum, also slightly coalescent, diameter of punctures at least as large as widest cross section of antennal segment 2. Abdomen elliptic, basal furrows of first segments moderately deep, tergite 7 with a narrow, sometimes incomplete membranous fringe apically; punctation of tergite 3 and the bases of tergites 4 and 5 coarse and dense, on the rest increasingly finer and sparser, punctures on tergite 7 nearly as large as one eye facet at dorsal eye margin, interstices four times or more as large as punctures; tergite 10 nearly smooth. Legs slender, metatarsi nearly as long as four fifths of the metatibiae, segment 1 about as long as the 3 following segments combined, nearly twice as long as the last segment. Fore-body with a very shallow reticulation, abdomen smooth.

Comparative note: This new species belongs to the S. cirrus- group and resembles several other Taiwanese species very much. For identification see key.

Etymology: Because of the erect pubescence of the abdomen I name this species " cirriostentans " (Lat.= presenting setae).

Figures

Figs 17-29: Ventral aspect of aedeagus of Stenus perpusillus nov.sp. (17, PT), S. sugayai nov.sp. (18, 19: Anmashan, PTT), S. perpinguis nov.sp. (20, T 28, PT), S. perspicabilis nov.sp. (21, Lalashan, PT), S. perpastus nov.sp. (22, T 92, PT), S. mysterialis PUTHZ (23, near Tadongshan), S. pervenustus nov.sp. (24, T 138, PT), S. persculptus nov.sp. (25, T 95, PT), S. perpropinquus nov.sp. (26, T 52, PT), S. cirriostentans nov.sp. (27, PT), S. perpauper nov.sp. (28, Fenchifu, PT), S. persculpturatus nov.sp. (29, T 101, PT). – Scale bar = 0.1mm (17= 18, 19, 20= 21-29).