Scaphisoma acutatum, Lobl, 2015

Löbl, Ivan, 2015, On the Scaphidiinae (Coleoptera: Staphylinidae) of the Lesser Sunda Islands, Revue suisse de Zoologie 122 (1), pp. 75-120 : 99

Scaphisoma acutatum sp. nov.

Figs 74-75

Holotype: SMNS; ♂; Indonesia, Lombok Is. Sapit- Sembalun Bumbung 14-16 Feb.1994 Bolm lgt., 900- 1500 m.

Paratype: MHNG; ♀; with the same data as the holotype.

Etymology: The species epithet is a Latin adjective, meaning pointed and referring to the shape of the apex of the median lobe.

Description: Length 1.85 mm, width 1.22 mm. Head, body and appendages almost evenly light brown, tibiae and tarsi slightly lighter than pronotum or elytra. Antennae long, length/width ratio of antennomeres as follows: III 14/8: IV 16/7: V 37/9: VI 53/11: VII 58/13: VIII 48/8: IX 60/14: X 57/15: XI 64/12. Pronotum very finely punctate, punctures dense, not well delimited, lateral margins hardly rounded, lateral margin carinae not visible in dorsal view. Point of scutellum exposed. Elytra with lateral margin carinae exposed in dorsal view, apical margins rounded, inner apical angle not prominent, situated somewhat posterior level of outer angles, sutural margin not raised, sutural striae shallow, parallel, curved at base and extending laterally about to basal mid-width, adsutural areas flat. Elytral punctation very fine and dense, similar to pronotal anterior mid-length, posterior mid-length consisting of punctures larger and not well delimited, with puncture intervals mostly about twice to three times as large as puncture diameters. Hypomera smooth. Mesepimeron about 1.5 times as interval to mesocoxa, about 4 times as long as wide. Metaventrite not microsculptured, slightly convex in middle, lacking impressions or sulci; punctation even, very fine and dense. Submesocoxal areas 0.04 mm, about as fifth of interval to metacoxa, submesocoxal lines convex, with fine marginal punctures. Metanepisternum flat, in level with metaventrite, not narrowed anteriad, with inner margin straight. Tibiae straight. Abdomen very finely punctate, with striate microsculpture. Submetacoxal areas 0.06 mm, submetacoxal lines convex, with fine margin punctures.

Male: Tarsomeres 1 to 3 of protarsi slightly widened, Aedeagus (Figs 74-75) 0.58 mm long, symmetrical, fairly sclerotized. Median lobe with basal bulb narrow, longer than apical process, lacking prominent articular process. Apical process fairly inflexed, gradually narrowed apically in dorsal view, with ventral side arcuate in lateral view. Parameres narrow, not lobed, hardly bent and narrowed in subapical parts in dorsal view, almost straight and slightly widened apically in lateral view. Internal sac without flagellum or other sclerotized pieces, membranes bearing denticulate structures.

Distribution: Indonesia: Lombok.

Type locality: Lombok, Sapit-Sembalun Bumbung, 900-1500 m.

Comments: The aedeagus of this species is similar to that of S. irideum Löbl, 2012 from the Moluccas island Halmahera, though the basal bulb is longer and the membranes of the internal sac are finely denticulate. It differs drastically from the latter by the not iridescent body, and from the congeners known from the Lesser Sundas by its short antennomere IV.