Neosclerus bicarinatus, Assing, 2011

Assing, Volker, 2011, A revision of the genus Neosclerus C (Coleoptera: Staphylinidae: Paederinae), Beiträge Zur Entomologie = Contributions to Entomology 6 (1), pp. 89-148 : 130-131

Neosclerus bicarinatus sp. n. ( Figs 151-156)

Type material:

Holotype : " Vietnam: Hatinh Pr., Raò An , 13 km W Huang Son, rt. 8, 7 km S Nuòc Sôt village, 18°21'N; 105°15'E, 300 m, V/9-22/1998, L. Herman, flight intercept trap / Holotypus  Neosclerus bicarinatus sp. n. det. V. Assing 2010 " ( AMNH) . Paratypes: 5 exs.: same data as holotype ( AMNH, cAss) .

Description:

Body length 2.7-3.2 mm. Habitus as in Fig. 151. Coloration: head blackish; pronotum darkbrown to blackish; elytra dark-brown, with the humeral angles and the posterior margin rather extensively reddish; abdomen brown to dark-brown; legs and antennae yellowish.

Head across eyes 1.15-1.20 times as wide as long; postocular region approximately as long as width of antennomere II ( Fig. 152); punctation moderately coarse and moderately dense in anterior portion, sparser in posterior portion of dorsal surface; interstices without distinct microreticulation and glossy (traces of microsculpture may be visible in posterior portion of dorsal surface); antenna approximately 0.9-1.0 mm long.

Pronotum weakly transverse, approximately 1.05 times as wide as long and approximately 0.85 times as wide as head ( Fig. 152); punctation similar to that of anterior portion of head or slightly less coarse; impunctate midline of variable width, narrow to moderately broad; interstices without microsculpture and glossy.

Elytra of variable length, 0.95-1.10 times as long as pronotum; humeral angles marked ( Fig. 152); punctation dense and moderately fine; interstices glossy. Hind wings apparently fully developed.

Abdomen slightly to distinctly narrower than elytra; punctation fine and moderately dense; interstices with very shallow, sometimes barely noticeable microsculpture; posterior margin of tergite VII with palisade fringe.

: sternite VII very distinctive, posterior margin broadly and shallowly concave in the middle, on either side of this concavity with pronounced tooth-like process, pubescence not distinctly modified ( Fig. 153); sternite VIII highly distinctive, anteriorly not distinctly elevated, but with pair of carinae of approximately 1/3 the length of sternite, median portion extensively without pubescence, posterior excision with approximately 10 marginal setae, not very acute, its depth approximately 1/5 the length of sternite ( Fig. 154); aedeagus with curved, subapically not dentate, and apically acute ventral process, internal sac in apical portion with pair of long sclerotized structures ( Figs 155-156).

Etymology:

The specific epithet (Latin, adjective: with two carinae) alludes to the distinctive modifications of the male sternite VIII.

Comparative notes:

Neosclerus bicarinatus is apparently most closely related to N .. glaber , as can be inferred from the similarly derived morphology of the aedeagus (shape of ventral process; pair of oblong sclerotized structures in apical portion of internal sac), the unmodified pubescence of the male sternite VII, and the similar external characters (punctation of the head and pronotum, absence of microsculpture on the head). The species is readily distinguished from its congeners by the coloration of the elytra (similar only to N .. rougemonti ) and the male sexual characters, particularly the dentate processes of the abdominal sternite VII (unique), the presence of a pair of carinae in the anterior portion of sternite VIII, and the shape of the ventral process of the aedeagus.

Distribution and bionomics:

The species is currently known only from one locality (altitude: 300 m) in Vietnam, but may be widespread in the Oriental region , as is suggested by the fact that the type specimens were collected on the wing (flight interception trap in May) .