Scaphisoma subgracile, 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 : 1353-1354

5.2.2.4. Scaphisoma subgracile nov.sp. (Figs 35, 48, 49)

T y p e m a t e r i a l: Holotype 6: Palawan: Central, Olangoan 18 km NE San Rafael, 5-6- XII.95 I. Löbl, fungi on logs, bark (MHNG). Paratypes: Palawan, with the same data as the holotype, 5 66, 9♀♀, 4 ex. sex not examined (MHNG, BZLA); Palawan Central, Sabang, trail to Underground River, sea level, 30.XI.1995, fungi on logs, leg. I. Löbl, 1 6 (MHNG); Palawan Central, Conception, sea level, I. Löbl, 6.-7.XII.1995, fungi on logs, bark, 2 66, 2 ♀♀ (MHNG); Palawan Central, Conception, large logs across Conception River, NE San Rafael, ca 20 m, 8.XII.1995, leg. J. Kodada & B. Rigová, 2 66, 1♀ (MHNG); Palawan, Binaluan, 7 66, 11 ♀♀ (SMTD, MHNG); Luzon, Lagunas Prov., Mt. Makiling, summit road (SE Los Banos) 600 m, 21- 22.XI.95, fungi on large logs, bark, leg. I. Löbl, 5 66, 4 ♀♀ (MHNG, BZLA); Luzon, Lagunas Prov., Mt. Makiling, 4 km S Los Banos, 11.IV.1977, leg. L.E. Watrous, 2 ex. (MHNG).

D e s c r i p t i o n: Length 1.0-1.35 mm, width 0.71-0.97 mm. Head, thorax, elytra and abdominal sternite 1 dark reddish-brown. Apical abdominal segments light brown to yellowish. Femora light brown, tibiae, tarsi and antennae usually lighter than femora, yellowish. Pronotum and elytra not microsculptured and not iridescent. Length/width ratio of antennomeres as: III 8/7: IV 12/6: V 22/8: VI 32/8: VII 50/13: VIII 30/9: IX 43/12: X 41/11: XI 57/12. Pronotum finely and densely punctate, with lateral margins evenly rounded, lateral margin carinae not or hardly visible in dorsal view, lateral striae impunctate. Exposed tip of scutellum minute. Elytra somewhat flattened, 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 not or somewhat raised, sutural striae fairly deep, bent at base, not extending along basal margin, parallel except near apices, fairly coarsely punctate; adsutural areas narrow, flat, each with single puncture row, lateral striae distinctly punctate. Elytral disc with punctation very fine, similar to that on pronotum on large humeral area and along lateral margin. Remaining punctation conspicuously coarse and very dense, with punctures to part larger than puncture intervals and well delimited, becoming gradually finer and sparser posterior middle third of elytra. Hind wings fully developed. Hypomera and mesanepisterna smooth. Mesepimera indistinct, fused. Metaventrite not microsculptured. Median part of metaventrite flattened, without impressions, fairly coarsely punctate, smooth between metacoxae, lateral parts of metaventrite with extremely fine and sparse punctation; antecoxal puncture rows absent. Submesocoxal areas 0.04-0.06 mm, about as half to two thirds of intervals to metacoxae, submesocoxal lines convex, fairly coarsely punctate, punctures not extended by striae. Metanepisternum flat, hardly narrowed anteriad, inner margin almost straight, suture conspicuously deep. Tibiae straight. Abdominal sternite 1 lacking obvious microsculpture, very finely and sparsely punctate, except on small basomedian area bearing distinct punctures; submetacoxal areas 0.07- 0.10 mm, as to twice as intervals to apical margin of sternite, submetacoxal lines strongly convex, distinctly punctate. Following ventrites with punctulate microsculpture.

M a l e: Protarsomeres 1 to 3 weakly widened. Aedeagus ( Figs 48, 49 ) 0.22-0.31 mm long, symmetrical, with basal bulb weakly sclerotized. Basal bulb very small. Articular processes large, prominent. Apical process of median lobe simple, long, at least twice as long as basal bulb, hardly inflexed, gradually narrowed or subparallel in dorsal view, subcylindrical and curved at tip in lateral view. Parameres narrow and long, weakly broadened apically in lateral view, almost evenly wide posterior bases in dorsal view, with membranous inner margin in basal third. Internal sac simple, with very narrow flagellum, spines and scale-like structures absent.

E t y m o l o g y: The species epithet is derived from the Latin sub meaning below and gracile meaning slender, referring to the shape of the aedeagus.

C o m p a r a t i v e n o t e s: This species shares with S. subconvexum most diagnostic characters, in particular the large submetaxocal areas and indistinct, fused mesepimera, both being derived character states. The new species may be distinguished from S. subconvexum by its elytral punctation that becomes gradually finer toward apices, as in S. simplex, and by the very narrow apical process of the median lobe of the aedeagus. The aedeagus of S. subgracile is similar to that in the New Caledonian S. nanulum LÖBL, 1972 and S. perpusillum LÖBL, 1972.

Figures

Figs 46 - 51: Aedeagi of Scaphisoma in dorsal and lateral views; (46, 47), S. simplexoides nov. sp.; (48, 49), S. subgracile nov. sp.; (50, 51), S. subplanatum nov. sp. Scale = 0.1 mm.