Coelostoma orbiculare (Fabricius, 1775)

Japarashvili, Shota, Bulbulashvili, Natalia, Seropian, Armen, Chkhartishvili, Tinatin, Iankoshvili, Giorgi, Chitadze, Beka, Balkhamishvili, Sopio, Arsenashvili, Eka, Todua, Mariami & Memishishi, Aleksi, 2023, New and well-forgotten: DNA-assisted records of two beetle (Insecta, Coleoptera) species new for the fauna of Georgia with an update on the distribution of some other little studied taxa, Caucasiana 2, pp. 63-70 : 63

Coelostoma orbiculare (Fabricius, 1775)

Materials

Examined:

GEORGIA • Ijareti; N41.6534°, E42.7048°; 1428 m a.s.l; 09.10.2021; ISU, CaBOL ID: 1018686. Poti; N42.1647°, E41.6896°; 1 m a.s.l.; 16.05.2021; ISU, CaBOL ID:1020485 (Fig. 2 ). East of village Mokhisi; N41.7188°, E44.4487°; 1635 m a.s.l.; 27.06.2021; ISU, CaBOL IDs: 1020505, 1020506, 1020507. North west of Ozni Village; N41.6400°, E43.8458°; 1961 m a.s.l.; 16.05.2017; ISU, CaBOL IDs: 1020131. Gonio; N41.5669°, E41.5669°; 2 m a.s.l.; 27.08.2019. Sakisto lake; N42.2871°, E45.2428°; 2250 m a.s.l.; 29.05.2022; ISU, CaBOL ID: 1033224. all leg: L. Mumladze.

Genetics:

Four barcodes of the species were obtained from specimens with CaBOL-IDs 1020485, 1020505, 1020506, and 1020507 (BOLD: AAF3894). The newly obtained barcodes were nearly identical (maximum p-distance 0.05%), with the nearest neighbor in BOLD systems being Coelostoma orbiculare from Finland (BIN ID: AAF3894, with mean p-distance 0.57%). The morphology of the Georgian specimens also perfectly corresponds to the descriptions provided in the keys by Medvedev (1965), Shatrovsky (1992), and Jia et al. (2014).

Remarks:

To date, 30 species of Hydrophilidae comprising 12 genera are known from Georgia ( Przewoźny 2022; Tarkhnishvili et al. 2013). The water-scavenger beetle genus Coelostoma includes more than 100 described species, with C. orbiculare and C. hispanicum ( Küster, 1848) being the only species of the genus in Europe ( Przewoźny 2022). All species of Coelostoma for which biology is known, including C. orbiculare , are aquatic and collected either directly among submerged plants at the edge of water or from wet places along streams, rivers, and standing water ( Shatrovsky 1992; Jia et al. 2014), where they may be found feeding on wet and submerged surfaces, including wet rocks and artificial concrete surfaces ( Jia et al. 2014). The species has a wide distribution in the Palaearctic region, with the nearest records from Azerbaijan, Armenia, and Central-European Russia ( Przewoźny 2022). The information on the occurrence of C. orbiculare in Tbilisi and Gomareti (Zaitsev 1953) was overlooked by subsequent authors, and since then, no study of the Hydrophilidae family in Georgia has been performed. Based on the material presented here, we can confirm that C. orbiculare has widespread distribution in Georgia (see Fig. 1 ).

Figures

Figure 1. Map of the beetle sampling sites in Georgia.

Figure 2. Coelostoma orbiculare (Fabricius, 1775), Ijareti. A - dorsal view; B - ventral view. Scale bar = 1 mm.