Scaphisoma caucasicum, Löbl, 2022

Löbl, I., 2022, On the genus Scaphisoma Leach, 1815 (Coleoptera: Staphylinidae: Scaphidiinae) from Georgia, with description of a new species, Caucasian Entomological Bulletin (Caucas. entomol. bull.) 18 (1), pp. 31-33 : 31-33

Scaphisoma caucasicum sp. n.

( Figs 1–3)

Material. Holotype, ♂ ( ZMB): “ GEORGIA [GE2021-60]: Svaneti, N Martvili , Lebarde valley , 42°37ʹ13ʺ N, 42°22ʹ45ʺ E, 510 m, track margin, mushroomssifted, 17.X.2021, leg. M. Schülke ”.

Description. Length 1.87 mm, width 1.25 mm. Head, pronotum and hypomere dark brown to reddish-brown. Elytra darker than pronotum on prevailing surface, becoming lighter posterior middle, and near lateral margins becoming lighter posterior basal third, light brown on entire apical fourth. Ventral side of thorax and ventrites Ito IV dark reddish-brown. Abdominal apex yellowish. Femora about as dark as pronotum, tibiae lighter, reddish, tarsi and antennomeres Iand II yellowish, following antennomeres light brown. Length/width ratios of the antennomeresas: III 16: 8, IV 27: 7, V 34: 8, VI 35: 10, VII 48: 15, VIII 38: 10, IX 48: 15, X 46: 15, XI 55: 15. Pronotumwithevenly rounded lateral margins, lateral margin carinae concealed indorsal view, disc not microsculptured, densely and very finely punctate, punctures mostly well delimited, visible at 20 times magnification, puncture intervals mostly about 3 to 5 times as large as puncture diameters; lateral striae impunctate; pubescence distinct. Exposed tip of scutellum minute, narrow, longer than wide. Elytra each with weakly rounded lateral margin, moderately narrowed apically, lateral margin carina nearly entirely concealed, exposed only near base in dorsal view; apical margin truncate, lacking crenulation at inner angle, inner angle not prominent, about at level of outer angle in dorsal view; sutural margin not raised, adsutural areaflat, narrowed apically, with fine puncture row, and additional very fine punctures forming second row in anterior third, sutural stria shallow, curved along base to form basal stria extended about to mid-width of basal margin; disc not microsculptured, with punctation mostly dense and rather coarse, puncture intervals mostly slightly larger to about twice as large as puncture diameters, punctures becoming much fine near base and along lateral stria; lateral stria distinctly punctate. Hypomera smooth. Mesepimeron about as long as interval between its tip and mesocoxa. Metaventrite not microsculptured, slightly convex between mesocoxae, flattened on apicomedian area; finely and densely punctate on median area smooth centre excepted, lacking impressions. Punctation on area between mesocoxa and metacoxa distinctly coarser than that on apicomedian area of metaventrite, anteriolateral surface of metaventrite nearly smooth. Submesocoxal area 0.05 mm, about as fourth of shortest interval to metacoxa. Submesocoxal line convex, finely punctate. Metanepisternum strongly narrowed anteriad, broadly rounded at angles, in plan with metaventrite. Tibiae straight. Exposed abdominal tergites with very miscosculpture consisting of very short striae and punctures. Exposed ventrites with strigulate microsculpture. Ventrite Iwith punctation about as fine as that on apicomedian area of metaventrite. Submetacoxal area 0.08 mm, about as fourth of interval to apical margin; submetaxocal line convex, finely punctate.

Male characters. Protarsomeres Ito III slightly widened, mesotarsomeres not widened. Aedeagus ( Figs 1–3) 0.56 mm long. Median lobe symmetrical, basal bulb weakly sclerotized, apical process strongly sclerotized, as long as basal bulb, strongly inflexed, with tip bent, acute in lateral view, not visible in dorsal view. Ostium subapical, overlapped by short dorsal plate. Articular process inconspicuous. Parameres slightly sinuate, nearly evenly wide in dorsal and lateral views, without lobes. Internal sac with proximal V-shaped plate-like structure, two very narrow admesal rods, very weakly sclerotized spines at each side of apical parts of rods, and two densely, well sclerotized apical spine bunches.

Differential diagnosis. Scaphisoma caucasicum sp. n. falls in the key to the Palaearctic species of Scaphisoma [ Löbl, 1970] to S. hapiroense Löbl, 1968 , couplet 33. This species was described and is known only from North Korea. Though the male characters of S. hapiroense remain unknown, the new species may be readily distinguished from it by the antennomere Vshorter than the combined length of the antennomeres III and IV, the very fine pronotal punctation, and the light apical area of the elytra weakly delimited. The aedeagal characters of S. caucasicum sp. n. are similar to those of S. latro Löbl, 2000 , currently known only from the Chinese provinces of Hubei and Sichuan [ Löbl, 2000, 2018, 2019]. However, S. latro is distinguished by the much shorter apical process of the median lobe and the internal sac lacking V-shaped structure and rods.

Distribution. Georgia: Svaneti.

Etymology. The species epithet is an adjective derive from the Caucasus, where the species occurs.