Scaphisoma longiusculum, Löbl, 2012

Löbl, Ivan, 2012, On a collection of Scaphisomatini (Coleoptera: Staphylinidae: Scaphidiinae) from West Malaysia, Acta Entomologica Musei Nationalis Pragae 52 (1), pp. 173-184 : 178-179

Scaphisoma longiusculum sp. nov.

( Figs. 8–10 )

Type material. HOLOTYPE: ♂, ‘ MALAYSIA, Pahang Cameron Highlands Tanah Rata vill. env. Gunung Jasat [Mt.] ; 1470–1705 m 04°28.4–7’ N, 101°21.6–22.1’ E Jiří Hájek leg. 18.iv.–10.v.2009 ’ ( NMPC). PARATYPES: 1 ♂, 5 ♀♀, same data as the holotype ( NMPC, MHNG).

Description. Length 1.60–1.70 mm, width 1.04–1.17 mm. Head and most of body dark reddishbrown to almost black, elytra each with light, ochraceous transverse subapical fascia, and at apices narrowly lighter. Subapical fascia expanded in outer half of elytra, not reaching elytral mid-length, apically reaching to posterior seventh of elytron. Apical abdominal segments, legs and antennomeres I to VI light ochraceous to yellowish, following antennomeres slightly darkened. Length ration of antennomeres as: II 10: III 3: IV 9: V 13: VI 12: VII 15: VIII 13: IX 15: X 14: XI 18 (holotype). Segments IV to VI narrow, V and VI slightly wider than IV, VI about 6 times as long as wide; segments VII and VIII each about 4 times as long as wide; segment XI about 4.5 times as long as wide. Pronotum with lateral margins evenly rounded, lateral margin carinae not visible in dorsal view, discal punctation fine, sparse, punctures well delimited. Tip of scutellum visible. Elytra moderately narrowed apically, with lateral margins rounded, lateral margin carinae exposed; apical margins trunctate, lacking serration; sutural margin not raised in basal half, weakly raised in apical half; adsutural areas flat, finely punctate; sutural striae starting at base, not curved laterally, weakly converging apically; discal punctation coarse, forming irregular longitudinal rows reaching subapical fasciae, with puncture diameters smaller than puncture intervals. Punctation on posterior fasciae very fine and irregular. Hypomera with barely visible microsculpture. Mesepimeron almost 1.5 times as long as interval to mesocoxae. Metaventrite lacking microsculpture, without basomedian impressions, centre weakly convex, with fairly coarse punctures in basomedian area, very finely punctate on anterior area. Lateral parts of metaventrite very finely punctate, each with antemetacoxal row of fine punctures. Submesocoxal lines slightly convex, submesocoxal areas 0.04 mm long. Metepisterna flat, 0.09 mm wide, narrowed anteriad, with inner suture moderately deep, almost straight between rounded angles. Exposed abdominal ventrites with striate microsculpture, microsculpture evanescent on basolateral parts of ventrite 1. Submetacoxal lines convex, fairly coarsely punctate, submetacoxal areas 0.05–0.06 mm long. Abdominal punctation very fine and sparse. Tibiae straight, mesotibiae and metatibiae evenly narrow.

Male. Segments 1 to 3 of protarsi slightly widened. Aedeagus ( Figs. 8–10 ) 0.72 mm long. Median lobe symmetrical, fairly strongly sclerotized. Apical process of median lobe longer than basal bulb, tapering, in lateral view sinuate. Parameres long and narrow, strongly curved in lateral view, widened apically. Internal sac with two weakly sclerotized plates covering scale-like structures and two mesal rods followed apically by dense spine-like structures.

Differential diagnosis. This species has the characters of the Scaphisoma rouyeri group (defined by the symmetrical aedeagus with mesally incompletely fissured dorsal wall of the apical process of the median lobe and the parameres each bearing a small mesal lobe, elytral punctation forming coarse longitudinal rows, abdomen with transversely striate microsculpture (see LÖBL 1981) except for the parameres which are not lobed mesally. The aedeagal characters suggest relationship with the Indian S. aurun Löbl, 1979 . The latter species has parameres widened more proximally and sclerotized plates of the internal sac situated centrally. Both species may be easily distinguished by their external characters, in particular by the uniformly brown body and very dense and irregular elytral punctation in S. aurun . Scaphisoma aurun was originally placed in the S. haemorrhoidale group, based on the shape of the parameres and the elytral punctation not arranged to form longitudinal rows ( LÖBL 1979).

Etymology. The name is a Latin adjective, referring to the long parameres of the aedeagus.

Figures

Figs. 8–9. Scaphisoma longiusculum sp. nov., aedeagus in dorsal (8) and lateral view (9). Scale bar = 0.2 mm.

Figs. 10–12. 10 – Scaphisoma longiusculum sp. nov., internal sac in dorsal view, scale bar = 0.1 mm. 11–12 – Scaphisoma edentatum sp. nov.: 11 – aedeagus in dorsal view, scale bar = 0.2 mm; 12 – internal sac in dorsal view, scale bar = 0.1 mm.