Trisunius thaicus, Assing, 2011

Assing, V., 2011, Trisunius gen. nov. from the southern East Palaearctic and the Oriental regions (Coleoptera: Staphylinidae: Paederinae: Medonina), Linzer biologische Beiträge 43 (1), pp. 195-220 : 217-218

Trisunius thaicus nov.sp. ( Figs 67-80 )

T y p e m a t e r i a l: Holotype Ƌ: "N-Thailand, Chiang Mai, Do Inthanon, Do Pui, 1100- 1500 m NN, 10.11.1995, P. Wunderle / Holotypus Ƌ Trisunius thaicus sp.n. det. V. Assing 2010" (cAss) . Paratypes: 2ƋƋ, 2♀♀, 1 ex. without abdomen: same data as holotype (cWun, cAss) ; 1♀: " Nordthailand : 1.1.1995, Prov: Chiang Mai, 10 km E. Mae Chaem, Doi Inthanon N. P., 1000 mH, Leg. Schulz & Vock" (cAss) ; 3♀♀: " Thailand, C.M. Doi Pui,:III:1987, Rougemont" (cRou) .

D e s c r i p t i o n: Body length 2.8-3.2 mm. Habitus as in Fig. 67 . Coloration: body reddish, with the abdomen slightly darker; legs dark-yellowish; antennae pale reddish.

Head ( Fig. 68 ) approximately as long as wide; punctation coarse and moderately dense, median dorsal portion impunctate; interstices without microsculpture ( Fig. 69 ). Eyes slightly longer than half the length of postocular region in dorsal view. Mouthparts: maxillary palpomere III somewhat flattened and strongly dilated ( Fig. 73 ); anterior margin of labrum with the external tooth-like process relatively short ( Fig. 70 ); mandibles as in Fig. 71-72 , right mandible with three teeth; labial palpi as in Fig. 74 .

Pronotum ( Fig. 68 ) weakly oblong, approximately 1.05 times as long as wide and about 0.95 times as wide as head; punctation similar to that of head, on either side of the broadly impunctate midline forming a series of approximately 15 punctures; interstices without microsculpture ( Fig. 75 ).

Elytra long, approximately 1.05-1.10 times as long and 1.25 times as broad as pronotum, not distinctly widened posteriad; humeral angles marked ( Fig. 68 ); punctation moderately dense, finer than that of head and pronotum; interstices without microsculpture. Hind wings fully developed.

Abdomen approximately as wide as elytra; punctation fine and dense on tergites III-VI, sparser on tergites VII-VIII; interstices with shallow, more or less isodiametric microsculpture ( Fig. 76 ); posterior margin of tergite VII with palisade fringe.

Ƌ: sternite VII posteriorly with cluster of relatively long setae on either side of middle, posterior margin weakly concave in the middle ( Fig. 77 ); sternite VIII with very narrow and acute posterior excision of approximately 1/5 the length of sternite, posterior margin and posterior median portion impunctate and without pubescence ( Fig. 78 ); aedeagus as in Figs 79-80.

E t y m o l o g y: The specific epithet is a latinized adjective derived from Thai, the people living in Thailand.

C o m p a r a t i v e n o t e s: This species is distinguished from all its congeners by by the conspicuous morphology of the aedeagus, the paler coloration, the shape and chaetotaxy of the male sternite VIII, and additionally from all of them, except T. appeniculatus, by the absence of microsculpture on the dorsal and the ventral surface of the head.

D i s t r i b u t i o n a n d n a t u r a l h i s t o r y: Trisunius thaicus is known only from two localities in northern Thailand. The specimens from the type locality were collected at an altitude of 1100-1500 m in November, those from Doi Pui in March.

Figures

Figs 67-80: Trisunius thaicus nov.sp.: (67) habitus; (68) forebody; (69) median dorsal portion of head; (70) labrum; (71-72) mandibles; (73) maxilla; (74) labial palpi; (75) median dorsal portion of pronotum; (76) abdominal tergite VII; (77) male sternite VII; (78) male sternite VIII; (79-80) aedeagus in lateral and in ventral view. Scale bars: 67: 1.0 mm; 68: 0.5 mm; 69, 75-78: 0.2 mm; 70-74, 79-80: 0.1 mm.