Scaphisoma hexamerum, Ivan Löbl & Ryo Ogawa, 2016

Ivan Löbl & Ryo Ogawa, 2016, On the Scaphisomatini (Coleoptera, Staphylinidae, Scaphidiinae) of the Philippines, IV: the genera Sapitia ACHARD and Scaphisoma LEACH, Linzer biologische Beiträge 48 (2), pp. 1339-1492 : 1369-1370

5.2.7.8. Scaphisoma hexamerum nov.sp. ( Figs 85, 86 )

T y p e m a t e r i a l: Holotype 6: Luzon: Lagunas Mt. Banahaw, above Kinabuhayan, 600- 700m, I. Löbl, 24.XI.95, degraded rainforest floor litter (MHNG).

D e s c r i p t i o n: Length 1.15 mm, width 0.83 mm. Head and body light brown, appendages lighter than body, yellowish. Pronotum and elytra not microsculptured and not iridescent. Antennomeres with length/width ratio as: III 11/5: IV 13/5: V 22/6: VI 48/7: VII 52/10: VIII 36/8: IX 43/10: X 45/11: XI 45/13. Pronotum finely and densely punctate, punctures well visible at 30 times magnification; lateral contours rounded, lateral margin carinae barely visible in dorsal view, lateral striae punctate. Exposed tip of scutellum minute. Elytra with lateral margin carinae not exposed in dorsal view, apical margins slightly rounded, inner apical angles not prominent, situated about in level with outer angles; sutural margin not raised, sutural striae fairly shallow, somewhat bent at base, not extending laterally, parallel from level of tip of scutellum toward apices, very finely punctate; adsutural areas narrow, very finely punctate. Lateral striae appearing impunctate. Elytra with discal punctation fine and dense, less fine than pronotal punctation, punctures comparatively well delimited, with puncture intervals mostly twice to three times as large as puncture diameters. Hind wings fully developed. Hypomera and mesanepisterna smooth, not microsculptured. Mesepimera about as long as intervals to mesocoxae and about three times as long as wide. Metaventrite very finely punctate, flattened and microsculptured in middle, with a fovea-like mesal impression, lateral parts lacking microsculpture; antecoxal puncture rows absent. Submesocoxal areas 0.02 mm, about as seventh of intervals to metacoxae, submesocoxal lines parallel, distinctly punctate. Metanepisternum flat, wide, parallel-sided, inner margin straight, suture deep. Tibiae straight. Abdomen with distinct strigulate microsculpture, very finely punctate. Sternite 1 with submetacoxal areas about 0.05 mm, about as halves of intervals to apical margin, submetacoxal lines convex, with distinct marginal punctures.

M a l e: Protarsomeres 1 to 3 weakly widened. Aedeagus ( Figs 85, 86 ) 0.43 mm long, symmetrical, moderately sclerotized. Apical process of median lobe much shorter than basal bulb, inflexed, with concave ventral side, tapering, tip blunt in dorsal view, acute in lateral view; articular processes prominent, notched. Parameres straight in basal halves, narrowed subapically and bent in apical section in dorsal view, reaching beyond tip of median lobe. Internal sac tubular, with dense spine-like structures.

E t y mo l o g y: The species epithet is Latinized Greek meaning consisting of six parts and referring to the conspicuous antennomere VI.

C o m p a r a t i v e n o t e s: This species is well characterized and may be easily distinguished from most of the Philippine congeners by its conspicuously elongate antennomere VI, S. minutipenis, S. apomontium and S. hexameroides excepted. Scaphisoma minutipenis differs drastically by the sutural striae of elytra extended along base to form basal striae and by the aedeagal characters. Scaphisoma hexameroides may be distinguished by its larger body-size, the metaventrite lacking mesal impression and the very distinctive aedeagus. Scaphisoma discretum LÖBL, 1986 from Assam possesses similar antennae though its distal antennomere is longer than the preceding segment. The latter may be easily distinguished by the submetacoxal areas with are much larger and by the internal sac of the aedeagus lacking distinct spine-like structures. See also notes under S. apomontium.

Figures

Figs 83 - 88: Aedeagi of Scaphisoma in dorsal and lateral views; (83, 84), S. densepunctatum nov. sp., scale = 0.2 mm; (85, 86), S. hexamerum nov. sp., scale 0.1 mm; (87, 88), S. kodadai nov. sp., scale = 0.1 mm.