Orsunius latexciscus, Assing, 2014

Assing, V., 2014, On Orsunius II. Eight new species and additional records (Coleoptera: Staphylinidae: Paederinae: Medonina), Linzer biologische Beiträge 46 (1), pp. 461-479 : 469

Orsunius latexciscus nov.sp.

( Figs 18-21 , 33 , Map 2 )

Type material Holotype: " Thailand, 23.-25.ii.1996, Ranong prov. 9°56' 98°40', Ranong: Hot Springs , K. Majer leg. / Holotypus Orsunius latexcisus sp.n. det. V. Assing 2013" ( NHMB) . Paratype: same data as holotype ( cAss).

Etymology: The specific epithet is an adjective composed of the Latin adjective latus (broad) and the past participle excisus. It refers to the broad posterior excision of the male sternite VIII.

Description: Body length 3.4-3.6 mm; length of forebody 2.1 mm. Habitus as in Fig. 18 . Coloration: forebody dark-brown, with the anterior margins and the humeral angles of the elytra yellowish; abdomen brown, with the posterior portion of segment VII and all of segment VIII dark-yellowish; legs yellowish; antennae reddish, with antennomere I infuscate.

Head ( Fig. 19 ) weakly transverse, approximately 1.05 times as broad as long and with moderately marked posterior angles; lateral margins behind eyes subparallel; posterior margin weakly concave in the middle; punctation moderately dense and conspicuously coarse; interstices without microsculpture; lateral margins without long black setae. Eyes large, approximately as long as postocular portion in dorsal view. Antennae 1.1-1.2 mm long; antennomeres VII moderately, and VIII-X strongly transverse, more than 1.5 times as broad as long. Anterior margin of labrum with U-shaped excision in the middle.

Pronotum ( Fig. 19 ) 1.10-1.15 times as wide as long and approximately as broad as head; posterior angles rounded, weakly marked; lateral margins without long black setae; punctation moderately dense and distinct, but less coarse than that of head; midline with more or less pronounced impunctate band; interstices without microsculpture.

Elytra ( Fig. 19 ) approximately 1.1 times as long as pronotum; punctation dense, finer than that of pronotum; interstices without microsculpture. Hind wings fully developed. Protarsomeres I-IV very weakly dilated. Metatarsomere I moderately slender, longer than II, but shorter than the combined length of II and III.

Abdomen narrower than elytra; punctation dense and extremely fine; interstices with distinct microreticulation; posterior margin of tergite VII with palisade fringe.

: sternite VII with weakly concave posterior margin; sternite VIII ( Fig. 33 ) approximately as long as broad and with shallow, broad posterior excision; aedeagus ( Figs 20- 21 ) small, 0.45 mm long, ventral process relatively short, distinctly curved in lateral view.

Comparative notes: This species is distinguished from other Orsunius species by the coloration, the conspicuously coarse punctation of the head, the distinctly transverse antennomeres VIII-X, the broad and shallow posterior excision of the male sternite VIII, and by the distinctive morphology of the aedeagus.

Distribution and natural history: The type locality is situated near Ranong in southern Thailand ( Map 2 ). The specimens were collected together with O. immsi , O. gladiator , O. flavovirgatus , and an undescribed species (represented by one female).

Figures

Map 2: Distributions of Orsunius gladiator (white and black circles), O. latexcisus (black circle), O. flavovirgatus (black circle), O. heissi (black star), O. stimulans (black and grey triangles), O. granulosus (white and grey triangles), O. cuneatus (white diamond), and O. spathulatus (black square).

Figs 18-25: Orsunius latexcisus nov.sp. (18-21) and O. flavovirgatus nov.sp. (22-25): (18, 22) habitus; (19, 23) forebody; (20, 24) aedeagus in lateral view; (21, 25) aedeagus in ventral view. Scale bars: 18-19, 22-23: 1.0 mm; 20-21, 24-25: 0.2 mm.

Figs 26-35: Orsunius granulosus nov.sp. (26-32), O. latexcisus nov.sp. (33) and O. flavovirgatus nov.sp. (34-35): (26) habitus; (27) forebody; (28) male sternite VII; (29, 33, 34) male sternite VIII; (30, 35) posterior portion of male sternite VIII; (31) aedeagus in lateral view; (32) aedeagus in ventral view. Scale bars: 26-27: 1.0 mm; 28-29, 31-34: 0.2 mm; 30, 35: 0.1 mm.