Scaphisoma opacum, 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 : 1383-1384

5.2.8.2. Scaphisoma opacum nov.sp. ( Figs 25, 112, 113 )

T y p e m a t e r i a l: Holotype 6: E. slope of Mt. McKinley, Davao Prov., Mindanao, Elev.3200ft. lot 54 IX, 7-8, 1946; beating / CNHM-Philippine Zool.Exped.(1946-47) F.G. Werner leg. (FMNH). Paratypes: with the same data as the holotype, 2♀♀ (FMNH, MHNG); Mindanao, Davao Prov., Baracatan, N. slope of Mt. Apo, Eagle Centre, 1100 m, 5.VIII.1985, leg. M. Sakai, 1 6 (MHNG); Mindanao, 30 km E of Malaybalay, Busdi, 1000 m, 5-9.V.1996, leg. Bolm, 1♀ (SMNS); Mindanao, Misamis occ., Don Victoriano, 1700 m, 1-3.V.1996, leg. Bolm, 1 6 (MHNG).

Description: Length 1.44-1.73 mm, width 1.03-1.12 mm. Head, body and appendages reddish-brown, appendages and apical abdominal segments lighter than most of body in darker specimens. Head and pronotum not microsculptured and not iridescent, elytra with distinct strigulate microsculpture and conspicuously dull. Length/width ratio of antennomeres as: III 12/7: IV 15/6: V 30/8: VI 43/10: VII 48/14: VIII 43/13: IX 49/12: X 49/13: XI 65/13. Pronotum very finely and densely punctate, punctures hardly visible at 50 times magnification, lateral contours evenly rounded, lateral margin carinae not visible in dorsal view, lateral striae impunctate. Exposed tip of scutellum minute. Elytra with lateral margin carinae exposed in dorsal view, apical margins slightly rounded, inner apical angles not prominent, situated posterior level of outer angles; sutural margin not raised, sutural striae shallow, bent at base, extending along basal margins to form basal striae reaching about elytral mid-width, parallel from level of tip of scutellum toward apices, impunctate; adsutural areas narrow, impunctate. Lateral striae impunctate. Elytral disc with punctation very fine and sparse, as that of pronotum. Hind wings fully developed. Hypomera, mesanepisterna, metaventrite and abdomen with strigulate microsculpture. Mesepimera longer than intervals to mesocoxae and about four times as long as wide. Metaventrite extremely finely punctate. Median part of metaventrite flattened, with fairly deep, elongate mesal impression; antecoxal puncture rows absent. Submesocoxal areas 0.04 mm, about as fourth of intervals to metacoxae, submesocoxal lines convex, distinctly punctate. Metanepisternum flat, narrow, slightly or not narrowed anteriad, inner margin almost straight, suture shallow. Protibiae straight, mesotibiae and metatibiae slightly curved. Abdomen with punctation very fine and sparse, hardly visible; submetacoxal areas about 0.03 mm, as fifth of intervals to apical margin of sternite, submetacoxal lines convex, with fairly coarse marginal punctures.

M a l e: Protarsomeres 1 to 3 distinctly widened. Aedeagus ( Figs 102 , 113 ) 0.40-042 mm long, symmetrical, fairly sclerotized. Apical process of median lobe shorter than basal bulb, gradually narrowed in dorsal view, almost tubular and weakly inflexed in lateral view, its narrowed and bent apical section excepted. Apex of median lobe blunt, articular processes not prominent. Parameres extended behind level of apex of median lobe, weakly curved in dorsal view, almost straight in lateral view, widened apically. Internal sac simple, with basal tube, membranes covered by denticular structures.

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

Co mpar a tive note s: The sole so far known Asian species of Scaphisoma possessing dull elytra are S. pecki LÖBL, 1982 from Japan and S. apparatum LÖBL, 2015 from Kalimantan. These species may be, however, readily distinguished: Scaphisoma pecki is 1.9 mm long, and has the pronotum clearly darker than the elytra, the elytral microsculpture consisting of meshes, the antennomeres IX to XI equally long, the sutural striae extended along basal margins of elytra, the metaventrite lacking microsculpture and bearing two apicomedian impressions, and the median parts of the metaventrite and sternite 1 bearing patches of dense and coarse punctures. Unlike S. pecki, S. opacum is about 1.4-1.7 mm long, has its body uniformly reddish-brown, the antennomere XI notably longer than the antennomeres IX or X, the elytral microsculpture consisting of striae, the sutural striae not extended along basal margins of the elytra, the metaventrite bearing a single, elongate mesal impression and strigulate microsculpture, and punctation entirely very fine, as that of sternite 1. The new species may be readily distinguished from S. apparatum by the short antennomere IV (in S. apparatum about twice as long as III), and the not darkened centre of elytra. The aedeagal characters of S. opacum suggest relationships with S. breviatum.

Figures

Figs 108 - 114: Aedeagi of Scaphisoma; (108, 109), S. subanun nov. sp., in dorsal and lateral views; (110, 111), S. breviatum nov. sp., in dorsal and lateral views; (112, 113), S. opacum nov. sp., in dorsal and lateral views; (114), S. elpis nov. sp., in dorsal view, without contours of proximal part of basal bulb. Scale = 0.1 mm.

Figs 101 - 107: Aedeagi of Scaphisoma in dorsal and lateral views; (101, 102), S. nabiluanum nov. sp., scale = 0.1 mm; (103, 104), S. obscurum nov. sp., scale = 0.1 mm; (105, 106), S. sagax nov. sp., scale 0.1 mm; (107), ditto, internal sac, scale = 0.05 mm.