Scaphisoma posticum, Löbl, 2023

Löbl, Ivan, 2023, On the Scaphidiinae (Coleoptera: Staphylinidae) of Java, Indonesia, Acta Musei Moraviae, Scientiae biologicae 108 (1 - 2), pp. 1-34 : 17-18

Scaphisoma posticum sp. nov.

( Figs 18 20 )

Type material. Holotype male, Java occident. Pengalengan , 4000, 1893, H. Fruhstorfer ( MHNG). Paratypes, 1 male, West Java, Preanger , G. Patoeho, 5000, 1925.IX.1926, F.C. Drescher ( MBBJ); 1 male, West Java, Preanger , G. Tangkoeban Prahoe , 4000 5000, 11.III.1920, F.C. Drescher ( MBBJ); 2 males, 2 females, W. Java, Mt. Gede , 50 km SE Bogor , 1400 1600 m, 5 6.XI.1989, Löbl, Agosti, Burckhardt ( MBBJ, MHNG).

Description. Length 1.80 2.05 mm, width 1.15 1.20 mm. Head, thorax, most of elytra and abdomen reddish­brown. Apical third of elytra yellowish. Appendages reddish­brown, lighter than thorax. Length/width ratios of antennomeres III 17 /8: IV 40 /7: V 53 /8: VI 52 /8: VII 62 /15: VIII 45 /8: IX 56 /13: X 49 /13: XI: 60/17. Pronotum and elytra lacking microsculpture. Pronotum with rounded lateral margins, lateral carinae exposed in dorsal view, lateral margin stria impunctate, discal punctation very fine and rather dense, punctures poorly delimited, hardly visible at magnification 20 times, puncture intervals clearly larger than puncture diameters. Tip of scutellum exposed, triangular. Elytron weekly narrowed apicad, with lateral margin rounded near base, nearly oblique in middle third; lateral margin carina exposed in dorsal view; lateral margin stria punctate; apical margin truncate; inner apical angle situated about the level of outer apical angle; apical crenulation present; sutural margin raised; sutural stria deep, gradually converging to suture, curved near base, not extending along basal margin; adsutural area flat, near scutellum about 0.08 mm wide, irregularly punctate; discal punctation very fine near base, on prevailing surface much coarser than that on pronotum, with punctures well delimited, puncture intervals mostly about as large to twice as large as puncture diameters. Hind wings fully developed. Hypomeron smooth. Mesanepisternum extremely finely and sparsely punctate, lacking microsculpture. Mesepimeron about four times as long as wide and slightly shorter than interval between its tip and mesocoxa. Metaventrite lacking striae or longitudinal impressions, with strigulate microsculpture evanescent between mesocoxae and on most of lateral areas, punctation very fine and dense between mesocoxae, very fine and sparse on most of lateral areas; middle of metaventrite convex, flattened anterior of metacoxal process and conspicuously densely and coarsely punctate, punctures sharply delimited; antecoxal puncture rows consisting of coarse punctures. Submesocoxal areas about 0.05 mm long, as long as fourth of shortest interval to metacoxa; submesocoxal lines convex, coarsely punctate. Metanepisternum flat, lacking microsculpture, narrowing anteriad, with suture straight except at rounded angles. Tibiae straight. Abdomen with strigulate microsculpture and very fine and sparse punctation, similar to punctation on metaventral sides. Ventrite I with submetacoxal areas 0.05 mm long, about as long as fourth of shortest interval to apical margin of ventrite, submetacoxal lines convex, coarsely punctate.

Male. Protarsomeres I to III distinctly widened, narrower than apex of protibia. Apical margin of ventrite VI with triangular lobe about 0.08 mm long. Aedeagus ( Figs 18 20 ) 0.73 0.82 mm long.

Etymology. The species epithet is a Latin adjective meaning behind.

Differential diagnosis. The species resembles S. flavapex by its size, colour, and sutural striae. It may be easily distinguished by the much longer antennomere IV, the antennomeres V and VI nearly evenly long, the elytral punctation coarser than the pronotal punctation, the metaventrite bearing microsculpture and with a patch of coarse punctures, the antemetacoxal puncture rows present, the ventrite I with submetacoxal areas much smaller and the submetacoxal lines coarsely punctate.

Figures

Figs 14-20. Male genitalia. 14, 15 – Scaphisoma neglectoides sp. nov., aedeagus in dorsal and lateral views, scale = 0.1 mm. 16, 17 – Scaphisoma planatoides sp. nov., aedeagus in dorsal and lateral views, scale = 0.2 mm. 18-20 – Scaphisoma posticum sp. nov. 18 – Aedeagus in dorsal view, scale = 0.1 mm. 19 – Ditto, paramere in ventral view, scale = 0.05 mm. 20 – Ditto, internal ac in dorsal view, scale = 0.05 mm.