Geostiba (Sibiota) granisuturalis, Assing, 2017

Assing, Volker, 2017, A revision of Geostiba of the West Palaearctic region. XXV. New species from Georgia and Greece, and additional records (Coleoptera: Staphylinidae: Aleocharinae), Linzer biologische Beiträge 49 (2), pp. 1093-1106 : 1102-1104

Geostiba (Sibiota) granisuturalis nov.sp. ( Figs 19-26 , Map 2 )

T y p e m a t e r i a l: Holotype 3: "N 43°06'15 E 42°35'50 (12), Georgien Svaneti , Mazeri 1660 m, Brachat & Meybohm, 26.6.2017 / Holotypus 3 Geostiba granisuturalis sp. n. det. V. Assing 2017 " (cAss) . Paratypes: 13, 2♀♀: same data as holotype (cAss) ; 533, 9 ♀♀: "N 43°01'20 E 42°45'00 (14), Georgien Svaneti Mestia-Hatsvali Bergstaion [sic] 2350 m, Brachat & Meybohm, 27.6.2017 " (cAss)

E t y m o l o g y: The specific epithet (adjective) alludes to the granulosely punctured suture of the male elytra.

D e s c r i p t i o n: Body length 1.9-2.4 mm; length of forebody 0.9-1.0 mm. Coloration: body dark-yellowish to reddish-yellow. Eyes reduced to minute rudiments without pigmentation and without ommatidia. Pronotum without impressions on either side of midline. Hind wings completely reduced.

3: elytra with weakly to moderately elevated suture, this elevation broader anteriorly than posteriorly, along suture with granulose punctures, disc more or less distinctly impressed; tergite VII ( Fig. 19 ) with median pair of short parallel carinae posteriorly; posterior margin of tergite VIII convex, with small concavity in the middle; posterior margin of sternite VIII obtusely produced posteriorly; median lobe of aedeagus ( Figs 20- 23 ) 0.27-0.29 mm long, without distinct flagellum and without semi-transparent spines in internal sac; paramere not distinctive.

♀: posterior margin of tergite VIII broadly convex, very shallowly concave to truncate in the middle; posterior margin of sternite VIII shallowly concave in the middle; distal portion of spermatheca ( Figs 24-26 ) not distinctly dilated.

C o m p a r a t i v e n o t e s: Among the Sibiota species known from the Greater Caucasus, G. granisuturalis is characterized by the combination of reduced eyes without ommatidia and pigmentation, relatively weakly elevated suture of the male elytra, and the primary sexual characters. It differs from G. recta ASSING, 2016 , the only other representative of the subgenus recorded from Svaneti, by paler coloration, smaller body size, less pronounced microsculpture on the forebody, the absence of distinct sutural carinae on the male elytra, shorter and parallel carinae on the male tergite VII, an aedeagus with a curved ventral process (lateral view), with a crista apicalis of different shape, and without a long flagellum in the internal sac, as well as by a proximally undilated spermatheca.

To account for the new species the key to the Sibiota species of the Caucasus region in ASSING (2016b) is modified as follows:

4. Male elytra with conspicuously elevated and narrow sutural carinae. Male tergite VII with median pair carinae strongly converging posteriorly (PACE 1995: figure 89). Median lobe of aedeagus with ventral process obtusely angled in lateral view (PACE 1995: figure 90). Spermatheca with undilated distal portion and with long and slender proximal portion (PACE 1996: figure 94). Distribution: West Georgia: environs of Batumi ( Map 1 ) ........................................................................................ batumiensis PACE

- Male elytra with less elevated and broader sutural carinae or elevation. Male tergite VII with median pair of carinae subparallel or weakly converging posteriorly .......................4a

4a. Sutural portion of male elytra weakly to moderately elevated, this elevation with row of granulose punctures on either side of suture; male tergite VII with median pair of short parallel carinae posteriorly ( Fig. 19 ). Median lobe of aedeagus and spermatheca as in Figs 21-26 . Distribution: Georgia: Svaneti ( Map 2 )........................... granisuturalis nov.sp.

- Sutural portion of male elytra (in large male) more strongly elevated. Primary sexual characters of different shapes. Unknown from Svaneti .......................................................5

D i s t r i b u t i o n a n d n a t u r a l h i s t o r y: Thespecimenswerecollected in two localities in Svaneti ( Map 2 ) by sifting leaf litter in a valley with alder, hazelnut, and fir, and in a birch forest with dense herb undergrowth (MEYBOHM pers. comm.) at altitudes of 1660 and 2350 m.

Figures

Map 1: Distributions of the species of the subgenus Tropogastrosipalia in the Caucasus region, based on examined records: G. svanetica (black diamond); G. gibberiventris (white diamond); G. tiflisensis (black circles); G. artvinensis (white circles); G. pontica (black square); G. solodovnikovi (black star); G. priva (white square); G. khnzoriani (black triangles).

Map 2: Distributions of the species of the subgenus Sibiota in the West and Central Greater Caucasus, based on examined records: G. articarinata (black diamond); G. convergens (white diamond); G. uniplicata (black triangle); G. krzysztofi (white circles); G. granisuturalis (black stars); G. recta (white triangles); G. artifistula (black squares); G. largata (white squares); G. kobrisensis (black circles).

Figs 19-26: Geostiba granisuturalis nov.sp.: (19) male tergites VI-VIII; (20-23) median lobe of aedeagus in lateral and in ventral view; (24-26) spermatheca. Scale bars: 19: 0.2 mm; 20-26: 0.1 mm.