Scaphisoma iridescens, 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 : 1402-1403

5.2.14.7. Scaphisoma iridescens nov.sp. ( Figs 150-152 )

T y p e m a t e r i a l: Holotype 6: Mainit Riv. Mt Apo / Mindanao IX.3. 7OP.I. / Coll. By C. F. Clagg / Altitude 7000 ft. / Field Mus (F. Psota Coll.) (FMNH).

Description: Length 1.85 mm, width 1.30 mm. Head, body and femora ochreous, tibiae, tarsi and antennae lighter than body, yellowish. Pronotum and elytra not microsculptured and not iridescent, mesanepisterna, lateral parts of metaventrite and abdomen iridescent. Length/width ratio of antennomeres as: III 17/10: IV 25/8: V 37/9: VI 65/11: VII 60/16: VIII 50/14: IX 60/17: X 57/16: XI 65/17. Pronotum very finely and fairly densely punctate, with lateral margins evenly rounded, lateral margin carinae not visible in dorsal view, lateral striae indistinctly punctate. Exposed tip of scutellum minute. Elytra with lateral margin carinae hardly visible in dorsal view, apical margins rounded, inner apical angles not prominent, situated about in level with outer angles; sutural margin not raised, sutural striae shallow, starting at each side of pronotal lobe, parallel between level of scutellar tip to apical third of sutural length, slightly converging toward apices, finely punctate; adsutural areas narrow, flat, densely and finely punctate, lateral striae indistinctly punctate. Elytral disc with punctation dense and fine, similar to pronotal punctation, puncture intervals much larger large than puncture diameters. Hind wings fully developed. Hypomera smooth. Mesanepisterna with distinct strigulate microsculpture, impunctate. Metaventrite entirely microsculptured; slightly convex, finely and very densely punctate in middle, with punctures to part about as large as puncture intervals, lacking impressions or stria; lateral parts of metaventrite impunctate and with distinct strigulate microsculpture. Submesocoxal areas 0.04 mm, about as fifth of intervals to metacoxae, submesocoxal lines convex, finely punctate. Metanepisternum flat, hardly narrowed anteriad, inner margin straight except at angles, not impressed below margin of metaventrite. Protibiae almost straight, becoming thicker toward apices, mesotibiae distinctly curved, metatibiae slightly curved, slender than mesotibiae. Abdomen with strigulate microsculpture, appearing impunctate; submetacoxal areas 0.04 mm, about as fourth of intervals to apical margin of sternite 1, submetacoxal lines convex, distinctly punctate.

M a l e: Protarsomeres 1 to 3 and mesotarsomeres 1 and 2 strongly widened, tarsomeres 1 wider than respective tibiae. Aedeagus ( Figs 150-152 ) 0.91 mm long, strongly sclerotized, symmetrical. Median lobe with large, bent basal bulb, robust articular process, and short, oblique ventral branch of apical process. Dorsal side of apical process wide, subtriangular, erected dorsally if internal sac extruded. Parameres arcuate in dorsal view, widened near base, narrowed apically; sinuate and gradually narrowed in lateral view. Internal sac with very fine denticular and spinel-like structures, lacking sclerotized pieces.

E t y m o l o g y: The species epithet derives from the Latin iris meaning rainbow and refers to the colour pattern of the ventral side of the body.

Comparative notes: This species may be readily distinguished by the microsculptured and iridescent mesanepisterna, lateral parts of metaventrite and abdomen, in combination with the large, 1.85 mm long body and the antennomere VI conspicuously long, longer than the antennomeres IV and V combined. The raised dorsal side of the median lobe as illustrated ( Fig. 151 ) is possibly produced by the extruded internal sac.

Figures

Figs 146 - 150: Aedeagi of Scaphisoma; (146, 147), Scaphisoma cuyunon nov. sp., in dorsal and lateral views, scale = 0.1 mm; (148, 149), S. hexameroides nov. sp., in dorsal and lateral views, scale = 0.2 mm; (150), S. iridescens nov. sp., in lateral view, scale = 0.2 mm.

Figs 151 - 156: Aedeagi of Scaphisoma; (151), S. iridescens nov. sp., aedeagus in dorsal view, internal sac extruded; (152), ditto, paramere in dorsal view, scale = 0.2 mm; (153, 154), S. werneri nov. sp., aedeagus in dorsal and lateral views, scale = 0.2 mm; (155, 156), S. dissymmetricum nov. sp., aedeagus in dorsal and lateral views, scale = 0.1 mm.