Scaphisoma hamatum, 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 : 1406-1407

5.2.16.1. Scaphisoma hamatum nov.sp. ( Figs 157-159 )

T y p e m a t e r i a l: Holotype 6: Mindanao, P.I.: Cotabato Prov.; 50 km. N. of Parang Elev. 500 ft. XII:6:1946 / on encrusting polypore / CNHM-Philippine Zool.Exped. (1946-47) F.G.Werner leg. (FMNH). Paratypes: with the same data as the holotype, 2 6 (FMNH, MHNG).

D e s c r i p t i o n: Length 1.60-1.70 mm, width 1.18-1.22 mm. Head and prothorax dark ochreous to dark reddish-brown. Elytra, mesoventrite and metaventrite slightly darker, brown. Abdomen light brown. Antennae light, almost yellowish. Legs light brown. Pronotum and elytra not microsculptured and not iridescent. Length/width ratio of antennomeres as: III 16/8: IV 32/6: V 53/8: VI 49/10: VII 70/15: VIII 42/9: IX 70/15: X 65/15: XI 82/15. Pronotum finely and densely punctate, with lateral margins evenly rounded, lateral margin carinae barely exposed in dorsal view, lateral striae impunctate. Tip of scutellum well visible. Elytra with lateral margin carinae entirely and well visible in dorsal view, apical margins rounded, inner apical angles not prominent, situated about in level with outer angles; sutural margin slightly raised in apical third, sutural striae deep, hardly bent at base and not extending along basal margin, parallel except near bases and in apical third, very finely punctate; adsutural areas flat, densely and very finely punctate, with punctures smaller than those on elytral disc, lateral striae finely punctate. Elytral disc with punctation coarse, punctures fairly well delimited, punctures intervals mostly about as large to twice as large as puncture diameters. Hind wings fully developed. Hypomera and mesanepisterna smooth. Mesepimera shorter than intervals to mesocoxae, about three times as long as wide. Metaventrite with mesal stria, impressed in posterior half of median part, with strigulate microsculpture, punctation dense and very fine in impression, sparse and very fine between mesocoxae. Lateral parts of metaventrite not microsculptured, sparsely and very finely punctate; antecoxal puncture rows present, in hardly impressed striae. Submesocoxal areas 0.04-0.05 mm, about as third of intervals to metacoxae, submesocoxal lines convex, finely punctate. Metanepisternum flat, hardly narrowed anteriad, inner margin almost straight, suture shallow. Protibiae and metatibiae straight, mesotibiae distinctly curved. Abdomen with strigulate microsculpture. Sternite 1 impressed and densely and finely punctate in middle, very finely and sparsely punctate on sides; submetacoxal areas 0.04-0.05 mm, about as third of intervals to apical margin, submetacoxal lines convex, finely punctate.

M a l e: Protarsomeres and mesotarsomeres 1 to 3 distinctly widened. Aedeagus ( Figs 157-159 ) 0.93-0.96 mm long, strongly sclerotized, symmetrical. Basal bulb much longer than apical process of median lobe, latter with dorsal branch partly exposed, ventral branch oblique, slightly sinuate and gradually narrowed toward tip (lateral view). Parameres dorsally overlapping. Internal sac with large, robust and strongly sclerotized hook, joint to tuft of long spines.

E t y m o l o g y: The species epithet is a Latin adjective meaning hooked.

Co mp ar a t i v e n o t e s: The aedeagal characters suggest relationships with S. palu LÖBL, 1983 from Sulawesi. The shape of the apical process of the median lobe of the new species, seen in lateral view, is diagnostic. In addition, S. hamatum may be readily distinguished by its colour pattern and the sutural striae of the elytra parallel while they diverge basally in S. palu. The internal sacs are extruded in the three available males.

Figures

Figs 157 - 161: Aedeagi of Scaphisoma in dorsal and lateral views; (157 - 159), S. hamatum nov. sp., internal sac extruded, scale = 0.2 mm; (159), ditto, apical part of median lobe with internal sac, scale = 0.1 mm; (160, 161), S. banguiense LÖBL, scale = 0.1 mm.