Scaphisoma hajeki, 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 : 176-177

Scaphisoma hajeki sp. nov.

( Figs. 5–7 )

Type material. HOLOTYPE: ♂, ‘ MALAYSIA, Perak Cameron Highlands Batu [=Mile] 19 vill. env. 04°22.2’ N, 101°20.0’ E, 590m Jiří Hájek leg. 5.–15.v.2009 ’ ( NMPC). PARATYPES: 3 ♂♂, same data as the holotype ( NMPC, MHNG).

Description. Length 2.30–2.35 mm, width 1.53–1.56 mm. Pronotum, elytra laterally and in apical fourth, and abdomen ochraceous. Large inner part of elytra darkened, rather light brown, darkened area extended laterally along base and posterior mid-length. Meso- and metaventrite slightly darker than prothorax. Head, antennomeres I to VI and legs lighter than prothorax, yellowish, antennal segments VII to XI slightly darkened. Antennae long, length ratio of antennomeres as: II 10: III 4: IV 13: V 22: VI 18: VII 20: VIII 16: IX 20: X 20: XI 19 (holotype). Segments IV to VI very narrow, about even in width; segment XI about 4 times as long as wide. Pronotum with lateral margins evenly rounded, lateral margin carinae throughout exposed in dorsal view, punctation fairly dense and very fine, punctures rather well delimited, coarser on small mediobasal area than on remaining discal surface. Tip of scutellum exposed. Elytra weakly narrowed apically, with evenly rounded lateral margins, lateral margin carinae distinct in dorsal view, apical margins rounded, lacking serration, inner apical angle situated posterior to level of outer apical angles; sutural margin not raised, adsutural areas flat, sutural striae parallel, starting at level of scutellum, slightly curved outwardly; basal striae absent; discal punctation fairly coarse and dense, most punctures distinctly smaller that puncture intervals. Exposed abdominal tergites very finely punctate, with striate microsculpture. Hypomera, mesepisterna, metaventrite and abdominal ventrites with striate microsculpture. Mesepimera shorter than intervals between them and mesocoxae. Metaventrite and abdominal ventrites very finely punctate, except for submesocoxal and submetacoxal rows of coarse punctures, metaventrite with fine antemetacoxal puncture rows. Middle of metaventrite convex, lacking impressions. Submesocoxal areas convex, 0.07 mm long. Metepisterna hardly convex, at widest point about 0.13 mm, slightly narrowed anteriad, with inner suture deep, sulciform, almost straight. Submetacoxal areas convex, 0.08 mm long. Protibiae barely curved, gradually thickened apically. Mesotibiae straight in basal fifth, distinctly curved between basal fifth and apex, throughout evenly thick. Metatibiae hardly sinuate, narrowed between mid-length and apical sixth, at apex thicker than in basal half.

Male. Tarsomeres 1 of prolegs and mesolegs strongly widened, almost as wide as apices of tibiae. Tarsomeres 2 of prolegs and mesolegs much narrower, still strongly widened, tarsomeres 3 weakly widened. Middle part of abdominal ventrite 6 prominent and truncate. Aedeagus ( Figs. 5–7 ) 1.57 mm long. Basal bulb large, oval, sub-symmetrical, weakly sclerotized basally, strongly sclerotized apically; ventral wall with low median ridge. Apical part of median lobe asymmetrical, consisting of two robust, strongly inflexed processes, dorsal process short, in axis with aedeagus, ventral process long, oblique, tapering in ventral view. Parameres symmetrical, each extended at base to form large process oriented proximally, and with large antebasal lobe, robust mesal denticle and explanate, rounded apex. Internal sac complex, with sclerotized plates in centre and membranous basal and apical parts consisting of scale-like structures.

Differential diagnosis. The peculiar shape of the mesotibiae may be a sexual character. This species is a member of the Scaphisoma tricolor group, defined by large aedeagi with strongly asymmetrical apical process of the median lobe and parameres bearing large ventral and dorsal lobes. The aedeagal characters of the new species suggest relationships with S. borneense Pic, 1916 from Kalimantan ( Indonesia) and S. luctuosum Löbl, 1986 from Meghalaya ( India), although the shape of the parameres is quite distinctive in each of these species. The new species may be readily distinguished by the presence of a median tooth on the inner side of the parameres, and externally by the colour of the body, un-shortened sutural striae of the elytra, and the comparatively short ultimate antennomere.

Etymology. The species is named in honour of its collector, Jiří Hájek, Praha, Czech Republic.

Figures

Figs. 5–7. Scaphisoma hajeki sp. nov. 5 – aedeagus in dorsal view; 6 – paramere in ventral view; 7 – aedeagus in lateral view. Scale bars = 0.3 mm.