Micrillus rougemonti, Assing, 2018

Assing, Volker, 2018, A revision of Palaearctic and Oriental Scymbalium and Micrillus III. New species, new combinations, and additional records (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 50 (2), pp. 977-996 : 994

Micrillus rougemonti nov.sp. ( Figs 41-45 )

T y p e m a t e r i a l: Holotype ♂ [abdominal apex damaged]: " CEYLON, Habarana, 15.III.81, Rougemont / Holotypus ♂ Micrillus rougemonti sp. n., det. V. Assing 2013" (cRou).

E t y m o l o g y: This species is dedicated to Guillaume de Rougemont, Oxford, who collected the holotype.

D e s c r i p t i o n: Body length 5.7 mm; length of forebody 3.1 mm. Habitus as in Fig. 41 . Coloration: head dark-brown with frons and posterior portion pale-reddish; pronotum pale-reddish; elytra brown with the suture and the posterior margins narrowly paler; abdomen reddish, with the middle of tergite VI darker brown; legs dark-yellowish; antennae pale-reddish.

Head ( Fig. 42 ) 1.1 times as long as broad, strongly convex in cross-section, rather large in relation to pronotum, and with weakly marked posterior angles; punctation fine and very sparse; interstices with pronounced microsculpture composed predominantly of transverse striae. Eyes large, approximately as long as postocular region in dorsal view. Antenna 1.8 mm long; antennomeres IV-VII weakly oblong, VIII-IX approximately as long as broad, and X weakly transverse. Maxillary palpus slender, apical palpomere needle-shaped and approximately half as long as palpomere III.

Pronotum ( Fig. 42 ) 1.23 times as long as broad and 0.9 times as broad as pronotum; lateral margins straight, very weakly converging posteriad in dorsal view; punctation fine, but less so than that of head, less sparse than that of head; midline broadly impunctate; interstices without microsculpture.

Elytra ( Fig. 42 ) 1.05 times as long as pronotum; punctation fine and moderately dense. Hind wings fully developed. Protarsomeres I-IV not dilated. Metatarsomere I approximately as long as combined length of II and III.

Abdomen approximately as broad as elytra; punctation rather sparse and moderately fine; interstices with distinct transverse microsculpture; posterior margin of tergite VII with palisade fringe; tergite X and sternite IX very small.

♂: posterior excision of sternite VIII broadly concave ( Fig. 43 ); aedeagus ( Figs 44-45 ) 0.45 mm long, symmetric, and weakly sclerotized, with distinctive internal structures.

C o m p a r a t i v e n o t e s: This species is characterized particularly by a relatively large, oblong, and distinctly convex head, by distinct transverse microsculpture of the head and abdomen, very sparse and fine punctation of the head, the shape of the male sternite VIII, as well as by the morphology of the aedeagus. For characters separating it from the closely allied M. coloratus see the comparative notes in the preceding section.

D i s t r i b u t i o n: The type locality is situated in central Sri Lanka. The holotype was sifted (Rougemont pers. comm.).

Figures

Figs 41-45: Micrillus rougemonti: (41) habitus; (42) forebody; (43) male sternite VIII; (44-45) aedeagus in lateral and in ventral view. Scale bars: 41: 1.0 mm; 42-43: 0.5 mm; 44-45: 0.1 mm.