Stenus aspripennis, Puthz, 2013

Puthz, V., 2013, Further new Stenus LATREILLE from Taiwan (Coleoptera, Staphylinidae) th, Linzer biologische Beiträge 45 (1), pp. 885-891 : 886-887

Stenus aspripennis nov.sp. (Figs 1, 6, 8, 9)

T y p e m a t e r i a l: Holotype (3) and 233- paratypes: TAIWAN: Nantou Hsien, Houhuanshan Kuenyang , 3050m, 27.IV.1990, A. Smetana ( T 29 ); 2♀♀ - paratypes: ibidem, 28.IV.1990, ibidem ( T 30 ).- HT and PTT in coll. A. Smetana (Ottawa), 1 PT in cP.

D e s c r i p t i o n: Brachypterous, black with a slight brownish hue, moderately shiny, head and pronotum coarsely and very densely punctate, elytra very coarsely, irregularly punctate, pronotum and elytra with many impressions, abdomen moderately coarsely (anteriorly) to finely (posteriorly), moderately densely punctate; pubescence very short, nearly imperceptible. Segment 1 of maxillary palpi yellow, segment 2 yellowish brown, segment 3 brown. Antennae dark brown. Legs chestnut-brown, posterior half of tibiae and tarsi dark brown. Clypeus black, labrum dark brown, scarcely pubescent.

Length: 3.4-3.6mm (forebody: 1.8-1.9mm).

PM of the HT: HW: 34.7; DE: 19; PW: 27; PL: 28; EW: 36; EL: 31; SL: 23.

M a l e: Femora clubbed, tibiae simple. Metasternum broadly and shallowly impressed, moderately coarsely, sparsely punctate, interstices deeply reticulate (fig. 8). Sternite 3 with a shallow median impression, which is sparser punctate than the sides of the sternite; sternite 4 with a broad and shallow posteromedian impression, also sparser punctate medially, sternites 5 and 6 with very broad and deep median impressions, the side of which are carinated and divergent posteriad, those of sternite 6 projecting posteriorly, punctuation and pubescence of impressions very fine and extremely dense, posterior margins broadly emarginated; sternite 7 in proximal half with a broad median impression, which becomes shallower posteriad, densely punctate and pubescent. Sternite 8 with a moderately narrow notch in about posterior fifth of the sternite. Sternite 9 acute apicolaterally. Tergite 10 broadly rounded at posterior margin. Aedeagus (fig. 1), apical portion of median lobe triangularly narrowed, expulsion hooks connected medially; parameres slightly longer than median lobe, narrowed apically, with 11 long setae in apical third.

F e m a l e: Metasternum also sparsely punctate (fig. 9). Sternite 8 obtusely- angled at posterior margin. Valvifer acute apicolaterally. Tergite 10 broadly rounded at posterior margin. Spermatheca (fig. 6), infundibulum short and broad.

Head slightly broader than elytra, frons broad with deep longitudinal furrows, median portion as broad as each of the side portions, strongly elevated like a longitudinal bump and (nearly) impunctate; punctuation of the side portions coarse and very dense, diameter of punctures about as large as median cross section of antennal segment 3, interstices much smaller than half diameter of punctures. Antennae moderately slender, when reflexed extending towards the posterior quarter of pronotum, penultimate segments 1/3 longer than broad. Pronotum slightly longer than broad, sides in anterior 2/3 strongly convex, posteriorly strongly concave; surface very uneven: a strong impunctate median impression in about anterior middle, several deep, punctate impressions on each side; punctuation coarse, dense and irregular, rarely confluent at places, diameter of punctures between largest cross section of antennal segment 3 and apical cross section of antennal segment 2, interstices mostly smaller than half diameter of punctures. Elytra trapezoid, much broader than long, shoulders moderately angled, sides distinctly widened behind, posterior margin deeply emarginated, suture gapes open posteriad; sculpture about similar to that of the pronotum, also very uneven: a long and deep sutural impression, a long humeral impression, and a transverse impression in anterior half; punctuation even coarser than on pronotum, punctures mostly as large as apical cross section of antennal segment 2, sometimes even larger. Abdomen broadly convex, paratergites slightly declining ventrad, moderately narrow, those of tergite 4 nearly as broad as antennal segment 2, with few fine scattered punctures; basal furrows of anterior tergites very deep, tergite 7 with a narrow apical membranous fringe; punctuation of tergite 3 coarse to moderately coarse, moderately dense (laterally) to moderately sparse (medially), finer on posterior tergites; on tergite 7 punctures are about as large as facets near medial eye margins, interstices as large as punctures or slightly larger, tergite 10 finely and moderately densely punctate. Legs strong, metatarsi 2/3 as long as metatibiae, segment 1 longer than segments 2 and 3 combined, slightly longer than segment 5; segment 4 deeply bilobed. The whole insect is reticulate in different depth.

C o m p a r a t i v e n o t e s: This new species and the following three are remarkable by the very uneven surface of pronotum and elytra. It is distinguished from the other non-spotted Taiwanese Stenus as indicated in the key below.

E t y m o l o g y: Because of the uneven suface of the forebody I name this new species " aspripennis " (Lat.= with uneven/rough elytra).