Witteia tensa Assing 2017, spec. nov.

Witteia tensa spec. nov.

urn:lsid:zoobank.org:act: 32B142EA-09BF-423E-8951-C710CE8AF383

(Figs 19, 61, 170–177)

Type material: Holotype ♂: “ CHINA: S-Yunnan (Xishuangbanna) 23 km NW Jinghong, vic Na Ben (NNNR) 730 m, N22°09.49, E100°39.92, rubber plantation, MF1, 30.X.2008, leg. A. Weigel / Holotypus ♂ Witteia tensa sp. n., det. V. Assing 2016” (NME). Paratypes: 2 ♀♀: same data as holotype, but “transition zone, MF1, 18.VII.2008 ” (NME, cAss); 1 ex. [teneral]: same data as holotype, but “transition zone, MF2, 20.X.2008 ” (NME); 1 ♀: same data as holotype, but “transition zone, MF1, 10.X.2008 ” (NME); 1 ♀: same data as holotype, but “transition zone, MF, 28.VI.2008 ” (NME); 1 ♀: same data as holotype, but “transition zone, MF, 12.V.2008 ” (cAss); 1 ♂: same data as holotype, but “transition zone, GSr, 28.VI.2008 ” (cAss). 1 ex.: same data as holotype, but “ 28.VI.2008, BF, leg. A. Weigel, rubb. plant. ” (cAss); 1 ex.: “ CHINA: S-Yunnan (Xishuangbanna), 20 km NW Jinghong, vic Man Dian (NNNR) / N22°07.80, E100°40.05, 730 m, 08.VII.2008, ricefield fallow, leg. A. Weigel MF” (NME); 1 ex.: “ CHINA: S-Yunnan (Xishuangbanna), 20 km NW Jinghong, vic Man Dian (NNNR) / N22°07.80, E100°40.05, 720 m, 30.X.2008, BF, leg. A. Weigel, rice fallow” (NME).

Etymology: The specific epithet (Latin, adjective: elongate, stretched) alludes to the conspicuously slender body (including all body parts) and the slender spermatheca.

Description: Body of very slender habitus, 5.6–6.5 mm long; length of forebody 3.5–4.0 mm. Coloration (Figs 19, 61): head black, except for the reddish-brown antero-median portion of the frons; pronotum reddishbrown to blackish-brown with the lateral margins broadly paler; elytra pale-brown to dark-brown; abdomen brown to dark-brown with the apex, the posterior margins of the tergites, and often also the paratergites and the anterior tergites paler; legs pale-brown to dark-brown; antennae reddish to dark-brown; maxillary palpi yellowish to reddish.

Head (Fig. 61) strongly transverse, nearly 1.5 times as broad as long, without sexual dimorphism; vertex with pronounced and extensive impression between eyes; punctation distinctly granulose and moderately sparse to moderately dense, often less dense in median impression; integument with pronounced microsculpture rendering the surface matt. Eyes enormous, occupying all of lateral margins of head, and strongly bulging (of similar shape as in species of Stenus LATREILLE, 1797). Antenna (Fig. 19) conspicuously long and slender, approximately 3 mm long; all antennomeres distinctly oblong.

Pronotum (Fig. 61) distinctly oblong, approximately 1.1 times as broad as long (or nearly so) and slightly less broad than head, without sexual dimorphism; lateral margins sinuate, sharply bordered, and broadly flattened; midline with sharply defined and rather deep sulcus extending nearly to anterior margin; punctation coarsely granulose and dense; interstices with pronounced microsculpture and matt.

Elytra (Fig. 61) approximately 0.85 times as long as pronotum; lateral margins delimited by a conspicuously sharp and elevated carina; punctation distinctly granulose, less dense and less coarse than that of pronotum; interstices with pronounced microsculpture and matt. Hind wings fully developed. Legs very long and slender; metatibia 1.4–1.5 mm long; metatarsus 1.2–1.3 mm long; metatarsomere I very slender, nearly as long as the combined length of metatarsomeres II–IV.

Abdomen slightly narrower than elytra; tergites III–IV with, tergite V with or without very shallow anterior impressions; punctation rather dense and fine; pubescence dense, short, and depressed; interstices with microreticulation composed of isodiametric meshes; posterior margin of tergite VII with palisade fringe.

♂: tergite VIII (Figs 173–174) oblong, posterior margin truncate and very finely crenulate in the middle; sternite VIII (Fig. 175) very weakly transverse and with convex posterior margin; median lobe of aedeagus (Figs 170–171) approximately 0.75 mm long, very slender both in ventral and in lateral view, subapically abruptly narrowed and apically acute in ventral view, and with a very prominent crista apicalis; paramere approximately 0.65 mm long and with rather long apical lobe.

♀: tergite VIII (Fig. 176) oblong, posterior margin weakly convex and not crenulate in the middle; sternite VIII (Fig. 177) weakly tranverse and with convex posterior margin; spermatheca (Fig. 172) long and slender, its maximal extension approximately 0.4 mm.

Comparative notes: This species is distinguished from the two previously known representatives of the genus by the much longer and more slender spermatheca, and additionally as follows: from W. dentilabrum by the darker coloration of the pronotum, elytra, abdomen, and legs, by the distinctly granulose punctation of the pronotum, and by the shape of the median lobe of the aedeagus; from W. borneensis (male unknown) by a more glossy forebody and a more distinctly granulose punctation of the pronotum.

For illustrations of W. dentilabrum and W. borneensis see MARUYAMA et al. (2010) and PACE (1987).

Distribution and natural history: The type specimens were collected in several close localities to the northwest of Jinghong, Xishuangbanna (China: Yunnan), mostly with Malaise traps. One teneral specimen was found in October. The host ant is unknown.