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Caucasian rock lizards (Darevskia) are a speciose group with 42 described species from the Caucasus Mountain region. We selected 11 species from Georgia and adjacent territories to explore whether their distribution depends on the distribution of congeneric taxa. We estimated two measures for each species pair: (1) niche overlap between all pairs of the studied species; (2) the extent of contact between the ranges of individual species. We then calculated the correlation between these measurements and the time of divergence between the species. The results showed that in sympatric and parapatric (but not allopatric) species, there is a highly significant correlation between the divergence time and the extent of the contact, as well as between the divergence time and the overlap of suitable habitats. The ranges of the evolutionarily closest species have the smallest extent of contact. Species separated later have overlapping ranges, although are separated by altitude. The most distant species, irrespective of their phenotype, are commonly found in the same location. We suggest that a gradual increase in the contact extent is compensated for by increasing the effectiveness of other mechanisms of niche shift or behavioural isolation and hence the frequency of potentially deleterious interspecific contacts is kept low. [ABSTRACT FROM AUTHOR]

This checklist reports 47 species of Psocoptera from 15 families and three suborders from Georgia, of which 31 species are recorded for the first time, increasing the known fauna of the country by more than 65%. Of these, 37 species have been barcoded, representing 210 Barcode Identification Numbers (BINs). An additional 14 species are expected to occur in Georgia but remain undiscovered, meaning that only? 77% of the fauna is currently documented. Barcodes, comments on distributions, and images of voucher specimens are given followed by a map of the sampling sites. [ABSTRACT FROM AUTHOR]

Visual inspection of several embryos of the parthenogenetic lizard Darevskia armeniaca revealed the presence of an embryo with axial bifurcation ("two-headed") on the stage of pigmented eyes and plate-like limb buds with a distinct border at the edges. This is the third recorded case of axial bifurcation in D. armeniaca, although two previous cases were mentioned without further discussion. Here the bicephalic embryo is described in detail and the potential reasons are discussed. The analysis of the literature on axial bifurcation in lacertids suggests that this type of developmental disorder may be particularly common in this parthenogenetic form. Hybridization may cause multiple developmental disorders, including incomplete separation of twin embryos; all parthenogenetic Darevskia have a hybrid origin, and this may cause the disorders rather than parthenogenetic reproduction by itself. The hypothesis needs further study with more representative samples of parthenogenetic and sexually reproducing Darevskia. [ABSTRACT FROM AUTHOR]

First records of two species of beetles (Insecta, Coleoptera), namely Pocadius adustus Reitter, 1888 (Nitidulidae) and Byrrhus pustulatus (Forster, 1770) (Byrrhidae) are given for Georgia. In addition, an update on the occurrences of Necrobia violacea (Linnaeus, 1758) (Cleridae), Coelostoma orbiculare (Fabricius, 1775) (Hydrophilidae) and Lycoperdina succincta (Linnaeus, 1767) (Endomychidae) are also presented based on the specimens collected in Samtskhe-Javakheti region, determined by morphological and mtDNA barcoding methods. [ABSTRACT FROM AUTHOR]

We genotyped multiple populations of all seven parthenogenetic species of rock lizards, genus Darevskia , as well as their putative sexual parental populations, using double digest RAD-sequencing genomic markers. Taking advantage of the conserved homology of the ZW/ZZ sex chromosomes among lacertid lizards, we aligned our short sequence reads to a reference Z chromosome assembly of the common wall lizard Podarcis muralis. This provided unique insight into the origin of all-female hybrid populations, which inherited their single Z chromosome exclusively from a paternal ancestor. The mapped Z-linked loci were used to construct a robust time-calibrated phylogeny. In each parent–offspring species pair, the geographically nearest population of the paternal species was identified as the most likely ancestor of the respective parthenogen, mirroring the trend observed previously on the maternal side in mitochondrial DNA. The estimated splits between the sampled paternal sexual ancestors and their daughter species occurred much earlier than suggested previously and during two narrow time periods: (1) the parthenogenetic Darevskia armeniaca , D. dahli , D. uzzelli and D. rostombekowi dated back to ~0.5 or ~0.9 Mya, depending on the calibration point used, while (2) D. bendimahiensis , D. sapphirina and D. unisexualis appear to have diverged ~1 or ~2 Mya. [ABSTRACT FROM AUTHOR]

The terrestrial woodlice Hemilepistus (Hemilepistus) klugii (Brandt, 1833) is reported from Georgia for the first time, with a commentary on the species composition of the genus Hemilepistus Budde-Lund, 1879 in the Caucasus. A short review of the ecology of the subgenus H. (Hemilepistus) is also provided. [ABSTRACT FROM AUTHOR]

Twentytwo snake species are recorded for Georgia. Over three years (2017–2019), social media (Facebook, iNaturalist and Instagram) was inspected to identify new snake records for Georgia. This led to an increase in the total number of known snake locations by 78% and this gain led to considerable growth of the Extent of Occurrence (up to 269%) and Area of Occupancy (up to 188%) data. The new locations identified by professional and amateur zoologists correlated with the number of locations known from scientific publications. In contrast, occasional sightings reported in social media only weakly correlated with published data, providing valuable information on highly mobile snakes of the family Colubridae, for which observation by professional herpetologists' are disproportionately rare. The study helped improve our knowledge of the range of individual species substantially. Specifically, a number of Colubridae known before only from eastern Georgia were recorded in suitable habitats in the country's western part. There were significant gains in knowledge for Elaphe dione, Zamenis hohenackeri, Hemorrhois ravergieri, and Vipera eriwanensis. Because IUCN categories for reptiles are dependent on the size and shape of their ranges, this information is highly useful for planning the conservation priorities for snakes in the country. [ABSTRACT FROM AUTHOR]

The Lebanon Lizard (Phoenicolacerta laevis) occurs on the Levantine coast and scattered populations are found in isolated coastal habitats along the southern and south-western coast of Turkey. We found an isolated but dense population of this species at and around the castle of Anaklia on Georgia’s Black Sea Coast, near the mouth of the river Enguri. The analysis of mitochondrial cytochrome b sequence suggests closeness of this population to the populations in the provinces of Kahramanmaraş, Adana and Içel in southern Turkey, rather than to those in Lebanon and Israel. It is thought that the species was introduced from a Turkish region to Anaklia, which was an important trade location at the eastern Black Sea coast until the late 18thcentury. This is the first established location of this species outside the eastern Mediterranean area. Climate and competition with rock lizards of the genusDarevskiaare the most likely reasons preventing expansion of the species into the neighboring areas of Western Georgia. [ABSTRACT FROM AUTHOR]

The impact of large-scale chromosomal rearrangements, such as fusions and fissions, on speciation is a long-standing conundrum. We assessed whether bursts of change in chromosome numbers resulting from chromosomal fusion or fission are related to increased speciation rates in Erebia, one of the most species-rich and karyotypically variable butterfly groups. We established a genome-based phylogeny and used state-dependent birth-death models to infer trajectories of karyotype evolution. We demonstrated that rates of anagenetic chromosomal changes (i.e., along phylogenetic branches) exceed cladogenetic changes (i.e., at speciation events), but, when cladogenetic changes occur, they are mostly associated with chromosomal fissions rather than fusions. We found that the relative importance of fusion and fission differs among Erebia clades of different ages and that especially in younger, more karyotypically diverse clades, speciation is more frequently associated with cladogenetic chromosomal changes. Overall, our results imply that chromosomal fusions and fissions have contrasting macroevolutionary roles and that large-scale chromosomal rearrangements are associated with bursts of species diversification. [ABSTRACT FROM AUTHOR]