Scaphisoma tarsale, Löbl, 2015

Löbl, Ivan, 2015, Notes on Scaphisoma of Kalimantan (Coleoptera: Staphylinidae: Scaphidiinae), Acta Entomologica Musei Nationalis Pragae 55 (1), pp. 129-144 : 141-143

Scaphisoma tarsale sp. nov.

( Figs 9–12 )

Type locality. Indonesia, East Kalimantan, ca. 55 km W of Balikpapan, PT Fajar Surya Swadaya area, 01°13.3′S, 116°21.0′E, 100 m a.s.l.

Type material. HOLOTYPE: ♂, ‘ Indonesia, E. Kalimantan, ca 55 km W of Balikpapan PT Fajar Surya Swadaya [area] 01°13.3’S 116°21.0’E, 100m J. Hájek, J. Schneider, P. Votruba leg. 24-25+ 29.xi.2011 / border of Acacia mangium plantation and primary rainforest, stream and waterfall, puddles; individual collecting, + light trap’ ( NMPC). PARATYPE: ♂, with the same data as the holotype but ‘ 23.xi.2011 ’ and ‘ base camp surrounded with Acacia plantation; individual collecting on vegetation, dead wood and in puddles, + light trap’ ( MHNG).

Description. Length 1.95–2.04 mm, width 1.36–1.38 mm. Head, pronotum and apical abdominal segments light reddish-brown, most of elytra, mesoventrite and metaventrite dark reddish-brown, apical fifth of elytra light, almost yellowish, ventrite 1 light, darkened near apical margin, appendages somewhat lighter than pronotum. Pronotum and elytra without microsculpture. Antennae with length/width ratio of antennomeres as follows: III 13/10: IV 46/9: V 67/9: VI 57/9: VII 65/13: VIII 50/8: IX 63/8 (antennomeres X and XI missing). Pronotum with lateral margins rounded, lateral margin carinae visible in dorsal view, discal punctation very fine, punctures dense, not well delimited, slightly larger on basomedian area than in middle, pubescence indistinct. Apical part of scutellum exposed. Elytra with lateral margin carinae exposed in dorsal view, apical margins slightly rounded, inner apical angle not prominent, situated somewhat posterior level of outer angles, sutural margin not raised, sutural striae shallow, starting posterior level of scutellum, almost parallel anterior mid-length, weakly converging posterior mid-length, indicated by puncture row in basal third of elytron; adsutural areas flat, with single puncture row, combined 0.15 mm at elytral mid-length. Elytral punctation coarse and dense, much coarser than pronotal punctation, consisting of punctures fairly well delimited, with puncture intervals mostly about 1.5 to 2 times as large as puncture diameters. Hypomera smooth. Mesepimeron somewhat shorter than interval to mesocoxa, about 3 times as long as wide. Metaventrite with distinct strigulate microsculpture, except on sides, in middle somewhat convex, with two shallow apicomedian, distinctly punctate impressions, antecoxal puncture rows present, in impressed lines, remaining punctation very fine and sparse. Submesocoxal areas 0.04 mm, about as quarter of interval to metacoxa, submesocoxal lines parallel, with coarse marginal punctures. Metanepisternum flat, somewhat below level of metaventrite, 0.12 mm wide, weakly narrowed anteriad, with inner margin almost straight, rounded near apical angles. Protibiae straight, mesotibiae distinctly curved, metatibiae hardly sinuate, slender than protibiae or mesotibiae. Abdomen with strigulate microsculpture. Intercoxal process of ventrite 1 with irregular transverse row of fairly coarse punctures, remaining surface of ventrites very finely and sparsely punctate. Submetaxocal lines convex, coarsely punctate, submetacoxal areas 0.06 mm, as fifth of interval to apical margin of ventrite.

Male characters. Protarsomere 1 strongly widened, about as wide as protibial apex, protarsomere 2 moderately widened, protarsomere 3 narrow, about as protarsomere 4. Mesotarsomere 1 conspicuously strongly enlarged, wider than mesotibial apex, mesotarsomere 2 about as wide as mesotibial apex, mesotarsomere 3 moderately widened. Ventrite 6 prominent apically, forming large, about 0.20 mm long, rounded lobe. Aedeagus ( Figs 9–12 ) about 1.15 (proximal part of median lobe damaged) – 1.22 mm long. Median lobe with ventral branch almost perpendicular to aedeagal axis, tapering, in dorsal view appearing sinuate. Dorsal branch of apical process sinuate in lateral view. Parameres with large, overlapping lobes attached to strongly sclerotized processes. Internal sac with basal and apical tufts of spine-like and scalelike structures, and three denticles, basal denticle transverse, following two denticles bent.

Differential diagnosis. This new species is similar to and likely closely related with S. tricolor Heller, 1917 , from the Philippines. It may be readily distinguished by the broadly triangular dorsal branch of the aedeagal apical process and by the shape of the sclerites of the internal sac, in particular the straight and comparatively short basal sclerite, and the absence of a plate between the two mesal sclerites.

Etymology. The species epithet refers to the shape of the strongly widened tarsi.

Distribution. Indonesia (Kalimantan).

Figures

Figs 9–12. Aedeagus of Scaphisoma tarsale sp. nov., in dorsal view (9), in lateral view (10), internal sac in dorsal view (11), parameres in ventral view (12). Scale bars = 0.2 mm.