Neosclerus anguliceps, Assing, 2017

Assing, Volker, 2017, A revision of Neosclerus CAMERON VI. Three new species from India, Thailand, and Vietnam (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 49 (1), pp. 317-325 : 318-320

Neosclerus anguliceps nov.sp. ( Figs 1-9 )

T y p e m a t e r i a l: Holotype Ƌ: " India: Kerala, Thiruvananthapuram distr., 0.6 km NE Kallar, rocky stream confluent to Kallar river , above huge rocks and pools / 08°42'50''N, 77°07'51''E, 190 m, 16.X.2016, leg. Gyurm; branches, rotting leaves on rough sand + gravel between stones, flotation / Holotypus Ƌ Neosclerus anguliceps sp.n. det. V. Assing 2017" ( NHMW) . Paratype Ƌ: India: Kerala, Thiruvananthapuram distr., 0.5 km N Kallar, stream confluent to Kallar river , shaded valley above small dam / 08°42'51''N, 77°07'50''E, 170 m, 13.X.2016, leg. Gyurm ; wet, rotten leaves between stones on bank, flotation" (cAss).

E t y m o l o g y: The specific epithet is a noun in apposition and alludes to the pronounced posterior angles of the head.

D e s c r i p t i o n: Body length 4.0- 4.2 mm; length of forebody 2.2-2.4 mm. Coloration: body black; legs yellow; antennae pale-reddish.

Head ( Fig. 1 ) 1.21-1.23 times as broad as long, with distinct temples and posterior angles (dorsal view); punctation of dorsal surface coarse, non-umbilicate, and rather dense, less dense in median dorsal portion; interstices without microreticulation; ventral surface with sparse punctation; gular sutures weakly pronounced, fused with ventral integument ( Fig. 2 ). Eyes large and bulging, but far from reaching posterior angles. Both mandibles ( Fig. 1 ) with two molar teeth. Labrum, labium, and ligula as in Figs 3-5 .

Pronotum ( Fig. 1 ) distinctly transverse, 1.12-1.13 times as broad as long and 0.88-0.90 times as broad as head; punctation similar to that of frons; interstices without microsculpture and glossy; midline narrowly impunctate, posteriorly finely sulcate.

Elytra ( Fig. 1 ) approximately as long as pronotum; punctation dense, somewhat less coarse than that of pronotum. Hind wings probably present. Metatarsomere I short, approximately as long as metatarsomere II or slightly longer.

Abdomen slightly narrower than elytra; punctation fine, denser on anterior than on posterior tergites; interstices with shallow microreticulation; posterior margin of tergite VII with palisade fringe.

Ƌ: sternite VII ( Fig. 7 ) moderately transverse, with weakly concave posterior margin, pubescence unmodified; sternite VIII ( Fig. 6 ) approximately as long as broad, posterior excision broad and approximately one-fifth as deep as length of sternite, pubescence unmodified; aedeagus ( Figs 8-9 ) approximately 0.75 mm long; ventral process of highly

distinctive shape: long, slender, apically hooked; internal sac with pairs of large dark structures.

C o m p a r a t i v e n o t e s: Neosclerus anguliceps is readily distinguished from all its described congeners by the shape of the head and by the distinctive shape of the ventral process of the aedeagus. In addition, it is characterized by relatively large size and a distinctly transverse pronotum. Its affiliations to any of the previously proposed species groups are unclear. Based on the presence of distinct temples, the posteriorly angled head, and the unmodified pubesence of the male sternite VIII it would best fit into the N. fortepunctatus group, which also includes the sole previously described representative of the genus in South India, N. revolutus ASSING, 2015 . From this species, N. anguliceps is distinguished by larger body size, a much more robust and broader habitus, completely different head shape, uniformly black coloration of the body, relatively shorter elytra, dense and coarse punctation in the posterior portion of the head, much denser punctation of the pronotum, less dense punctation of the elytra, and by the male primary and secondary sexual characters.

For illustrations of previously described Neosclerus species see ASSING (2011a, b, 2013, 2014, 2015).

D i s t r i b u t i o n a n d b i o n o m i c s: The type locality is situated in Kerala province, Southwest India. The specimens were floated from leaf litter on stream banks at altitudes of 170 and 190 m.

Figures

Figs 1-9: Neosclerus anguliceps nov.sp.: (1) forebody; (2) antero-median portion of ventral aspect of head; (3) labrum; (4) labium; (5) ligula; (6) male sternite VIII; (3) postero-median portion of male sternite VIII; (7) male sternite VII; (8-9) aedeagus in lateral and in ventral view. Scale bars: 1: 1.0 mm; 2, 4, 6-9: 0.2 mm; 3, 5: 0.1 mm.