Scaphisoma acutulum, 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 : 1416-1417

5.2.19.1. Scaphisoma acutulum nov.sp. ( Figs 180, 181 )

T y p e m a t e r i a l: Holotype 6: Philippines: Leyte Visca N Baybay, 1991 prim. forest 200- 500m leg. Schawaller et al. / 2.3.91 (SMNS). Paratypes: with the same data as the holotype but 22.2.-10.3, 2 66 (SMNS, MHNG).

Description: Length 1.52-1.57 mm, width 1. 05-1.10 mm. Body uniformly reddish-brown, appendages lighter than body. Pronotum and elytra not microsculptured and not iridescent. Length/width ratio of antennomeres as: III 12/7: IV 33/6: V 50/6: VI 42/7: VII 55/12: VIII 43/9: IX 55/13: X 53/13: XI 65/14. Pronotum very finely and fairly densely punctate, with lateral contours evenly rounded, lateral margin carinae throughout visible in dorsal view, lateral striae finely punctate. Tip of scutellum exposed. Elytra with lateral margin carinae entirely visible in dorsal view, apical margins rounded, inner apical angles not prominent, situated posterior level of outer angles; sutural margin not raised, sutural striae deep, slightly curved near base, parallel toward apical third of sutural length, converging toward apices, fairly finely punctate; adsutural areas narrow, flat, each with fairly dense and fine puncture row, lateral striae distinctly punctate. Elytral disc with punctation fairly coarse and dense, puncture intervals mostly about as large to three times as large as puncture diameters. Hypomera and mesanepisterna smooth. Mesepimera about twice as long as intervals to mesocoxae, about four times as long as wide. Median part of metaventrite convex, not microsculptured between mesocoxae and very finely punctate, posterior part of metaventrite impressed, lacking mesal or apicomesal impressions or striae, coarsely punctate and with strigulate microsculpture. Lateral parts of metaventrite with punctation very fine and sparse, coarse antecoxal puncture rows excepted. Submesocoxal areas 0.03 mm, about as fourth of intervals to metacoxae, submesocoxal lines convex, coarsely punctate. Metanepisternum convex, narrowed anteriad, inner margin rounded, impressed below margin of metaventrite. Protibiae and metatibiae straight, metatibiae somewhat narrowed posterior middle; mesotibiae slightly bent. Abdomen with strigulate microsculpture, very finely punctate; submetacoxal areas 0.04-0.05 mm, about as third to almost as half of intervals to apical margin of sternite 1, submetacoxal lines convex, coarsely punctate.

M a l e: Protarsomeres and mesotarsomeres 1 to 3 distinctly widened. Aedeagus ( Figs 180, 181 ) 0.72-0.74 mm long, fairly strongly sclerotized, symmetrical. Median lobe with elongate basal bulb, robust, not prominent articular process and ventral branch of apical process strongly inflexed, tapering and sinuate in lateral view, abruptly narrowed in apical section in dorsal view. Dorsal branches of apical process short, weakly sclerotized. Parameres wide, with large lobes, in dorsal view curved and overlapping apically. Internal sac with robust mesal tooth, bunch of long apical spines and finely denticulate structures in basal and admesal sections.

E t y m o l o g y: The species epithet is a Latin adjective meaning somewhat pointed. C o m p a r a t i v e n o t e s: The shape of the aedeagus is diagnostic. The species is similar in external characters to S. boettcheri PIC. The structure of the internal sac resembles that in S. innotatum PIC, 1926 known from India, Thailand and Vietnam, but the shape of the median lobe and parameres is distinctive.

Figures

Figs 177 - 183: Aedeagi of Scaphisoma; (177), S. surigaosum (PIC), in lateral view, scale 0.2 mm; (178, 179), S. transversale nov. sp., in dorsal and lateral views, scale = 0.1 mm; (180, 181), S. acutulum nov. sp., in dorsal and lateral views, scale = 0.2 mm; (182, 183), S. apomontanum nov. sp., in dorsal and lateral views, scale = 0.2 mm.