Geostiba (Tropogastrosipalia) simplicicollis nov.sp. (Figs 1-7)

T y p e m a t e r i a l: Holotype ♂: " N42°13'07 E45°18'40, GG Kakheti Birkiani N, 750 m, 11.5.2019, leg. Meybohm & Brachat (6) / Holotypus ♂ Geostiba simplicicollis sp. n. det. V. Assing 2019" (cAss) . Paratypes: 1♂, 1♀: same data as holotype (cAss); 1♀: " N42°13'24 E45°19'15, GG Kakheti Birkiani N, 760 m, 11.5.2019, leg. Brachat & Meybohm (5)" (cAss) .

E t y m o l o g y: The specific epithet (Latin, adjective) alludes to the unmodified male pronotum.

D e s c r i p t i o n: Body length 2.9-3.4 mm; length of forebody 1.1-1.3 mm. Habitus as in Fig. 1. Coloration: body reddish to brown with abdominal segments VI and VII more or less distinctly infuscate; legs yellow; antennae dark-reddish to brown with the basal 2-3 antennomeres reddish.

Pronotum (Fig. 2) without evident sexual dimorphism, approximately as broad as long and with weakly convex posterior margin. Elytra with very weakly pronounced sexual dimorphism.

Large ♂: elytra (Fig. 2) with noticeably granulose punctation, without other modifications such as carinae or impressions; anterior tergites unmodified; tergite VII with pronounced and apically acute median spine near posterior margin (Figs 3-4); median lobe of aedeagus 0.27-0.28 mm long and shaped as in Figs 5-7.

♀: elytra with very fine and non-granulose punctation.

C o m p a r a t i v e n o t e s: Five species of the subgenus Tropogastrosipalia SCHEERPELTZ, 1951 were previously known from the Greater Caucasus and its western extensions. The geograpically closests representatives are Geostiba gibberiventris ASSING, 2017 (Georgia: Mtskheta-Mtianeti) and G. tiflisensis PACE, 1996 (Georgia: Ananuri and region to the southwest of Telavi) (ASSING 2017b). Geostiba simplicollis is distinguished from both of them by the unmodified male pronotum, the shape of the cristal process of the aedeagus, and additionally as follows:

from G. gibberiventris by weakly modified male elytra (G. gibberiventris: elytra with sutural carinae) and unmodified male tergites III and IV (G. gibberiventris: male tergites III and IV with a median tubercle;

from G. tiflisensis by weakly modified male elytra ( G. tiflisensis: male elytra largely and distinctly impressed, near scutellum with dense and very coarsely granulose punctation.

For illustrations of G. gibberiventris and P. tiflisensis see ASSING (2017c).

D i s t r i b u t i o n: The type specimens were found in two geographically close localities to the northwest of Telavi, Kakheti region, at an altitude of approximately 750 m. They were sifted from leaf litter in deciduous forests.