Scaphisoma angulare, Lobl, 2015

Löbl, Ivan, 2015, On the Scaphidiinae (Coleoptera: Staphylinidae) of the Lesser Sunda Islands, Revue suisse de Zoologie 122 (1), pp. 75-120 : 105-107

Scaphisoma angulare sp. nov.

Figs 87-90

Holotype: SMNS; ♂; Indonesia, W. Sumbawa Batudulang , 30 km S of Sumb. Besar, 1000 m Bolm lgt. 10. Febr. 1994.

Paratypes: SMNS, MHNG; 7 ♂, 1 ♀; Indonesia, with the same data as the holotype.

Etymology: The species epithet is a Latin adjective, meaning angulate and referring to the shape of the elytra.

Description: Length 1.93-2.10 mm, width 1.25-1.33 mm. Head, pronotum and hypomera very dark reddish-brown to blackish-brown. Elytra black, with base somewhat lighter, adsutural areas about as pronotum, at apices yellowish. Metaventrite very dark reddish-brown to blackish, abdomen dark brown or reddish-brown. Appendages light reddish-brown to yellowish. Pronotum and elytra lacking microsculpture. Antennae long, length/width ratio of antennomeres as follows: III 16/8: IV 40/8: V 55/10: VI 51/9: VII 58/14: VIII 51/10: IX 57/10: X 55/14: XI 65/15. Antennomere III subtriangular. Pronotum finely and densely punctate, with lateral margins evenly rounded, basal halves of lateral margin carinae visible in dorsal view. Apex of scutellum exposed. Elytra with lateral margin carinae entirely exposed in dorsal view, apical margins truncate, inner apical angle rectangular, not prominent in male, prominent and tooth-like in female; situated posterior level of outer angles, sutural margin not raised, sutural striae deep, parallel, hardly curved at base, not extending laterad pronotal lobe, adsutural areas flat. Elytral punctation fairly coarse, dense, punctures well delimited, puncture intervals mostly about as large to twice as large as puncture diameters. Hypomera smooth. Mesepimera longer than interval to mesocoxa. Metaventrite with microsculpture striagulate, distinct on median area, hardly visible on lateral areas. Median area of metaventrite slightly convex, with two indistinct apicomedian impressions, punctation fine but distinct apicomedianly, elsewhere very fine. Submesocoxal areas 0.04 mm, about as fifth of intervals to metacoxae, submesocoxal lines subparallel, with coarse marginal punctures. Metanepisternum flat, hardly narrowed anteriad, with inner margin straight in middle, rounded near angles, impressed below margin of metaventrite. Tibiae straight. Abdomen with microsculpture consisting of transverse striae. Sternite 1 all over very finely punctate. Submetacoxal areas 0.07-0.08 mm, submetacoxal lines convex, with coarse margin punctures.

Male: Protarsal and mesotarsal segments 1 to 3 distinctly widened. Inner apical angle of elytra not prominent. Aedeagus (Figs 87-90) 1.07-1.10 mm long. Median lobe and parameres symmetrical, strongly sclerotized. Median lobe with large basal bulb, ventral branch of apical process short, weakly inflexed in apical half, with subapical dorsal denticle, dorsal branches of apical process slightly shorter than ventral branch, articular process not prominent. Parameres in level with median lobe, arcuate in basal part, oblique posterior basal part, narrowed toward apices in lateral view, sinuate in dorsal view, lacking distinct crenulations; pores scattered, situated in basal halves. Internal sac complex, with tufts of dense denticles, large median tooth, and membranes bearing scalelike structure.

Female: Inner apical angle of elytra prominent, toothlike.

Distribution: Indonesia: Sumbawa.

Type locality: W. Sumbawa Batudulang, 30 km S of Sumb. Besar, 1000 m.

Comments: The aedeagus of this species is very similar to that of S. sapitense , suggesting close relationships. Possibly, these species are vicariant. The new species differs however conspicuously from S. sapitense by its colour pattern, and also by the very finely punctate basomedian part of the sternite 1 and the laterally microsculptured metaventrite. The aedeagi are in both species similar. Unlike S. sapitense , S. angulare has parameres distinctly sinuate in dorsal view and its internal sac bears a large median tooth, while it lacks the row of scale-like, flat sclerites.