New species of bristletails of the family Machilidae (Microcoryphia) from caves in Abkhazia and Ukraine.

Two new species of bristletails of the family Machilidae are described from caves in the Western Caucasus (troglophile Coryphophthalmus troglophilus sp. nov.) and in the Eastern Carpathians (trogloxene Trigoniophthalmus ukrainensis sp. nov.). The main morphological adaptations of C. troglophilus sp. nov. to life in caves include green eye color; weak body pigmentation; well-developed arolium and claws; relatively long cerci, tarsae and tibiae of the hind legs; long apical needles of the urostyli; large sublateral spines on urocoxites IX. C. troglophilus sp. nov. resembles C. abchasicus (Kaplin, 2017), but they are distinguishable in color of eyes, ratio of eye contact to length, length of cerci, structures of the labial palps, legs, urocoxites IX, ovipositor, and parameres. Trigoniophthalmus ukrainensis sp. nov. has no recognized morphological adaptations to life in caves. This species resembles T. alternatus (Silvestri, 1910), but they are easily distinguished in the number of annuli in distal chains of flagellum, ratio of width to length of paired ocelli, chaetotaxy of male maxillary and labial palps.

A new species of Arrhopalites Börner, 1906 (Collembola, Symphypleona, Arrhopalitidae) from Iran with an updated key to A. diversus group of species.

A new springtail species of the family Arrhopalitidae, Arrhopalites persicus sp. nov., is described from Kermanshah Province in Iran. It belongs to the diversus group of species with 3, 2, 1, 1 anterior setae on dens. It is separated from all members of this group by presence of 5+5 circumanal spines on the sixth abdominal segment and it shows reduced tibiotarsal chaetotaxy. It is the second species of the genus recorded in the country. A key to Arrhopalites diversus group of species is updated.

Cave water walker: an extremely troglomorphic Troglaphorura gladiator gen. et sp. nov. (Collembola, Onychiuridae) from Snezhnaya Cave in the Caucasus.

A new springtail genus and species of the family Onychiuridae, Troglaphorura gladiator gen. et sp. nov., is described from deep Snezhnaya (Snow) Cave System (-1760 m) in the West Caucasus. Postantennal organ with only a single unlobed vesicle, sense organ of third antennal segment with sensory rods of complex structure, foot complex with missing empodia and extremely long thin claws as well as relatively long appendages, primitive dorsal chaetotaxy and presence of 1+1 pseudocelli on the head posterior part are extraordinary characters within the family but diagnostic for new genus and species. Extreme troglomorphy of new species is discussed. It was sampled in epineustonic habitats in bottom part of the cave and represents a genuine example of troglomorphic neustonic and hygropetric collembolan life form-a cave water walker.

Continental data on cave-dwelling spider communities across Europe (Arachnida: Araneae).

BACKGROUND: Spiders (Arachnida: Araneae) are widespread in subterranean ecosystems worldwide and represent an important component of subterranean trophic webs. Yet, global-scale diversity patterns of subterranean spiders are still mostly unknown. In the frame of the CAWEB project, a European joint network of cave arachnologists, we collected data on cave-dwelling spider communities across Europe in order to explore their continental diversity patterns. Two main datasets were compiled: one listing all subterranean spider species recorded in numerous subterranean localities across Europe and another with high resolution data about the subterranean habitat in which they were collected. From these two datasets, we further generated a third dataset with individual geo-referenced occurrence records for all these species. NEW INFORMATION: Data from 475 geo-referenced subterranean localities (caves, mines and other artificial subterranean sites, interstitial habitats) are herein made available. For each subterranean locality, information about the composition of the spider community is provided, along with local geomorphological and habitat features. Altogether, these communities account for > 300 unique taxonomic entities and 2,091 unique geo-referenced occurrence records, that are made available via the Global Biodiversity Information Facility (GBIF) (Mammola and Cardoso 2019). This dataset is unique in that it covers both a large geographic extent (from 35° south to 67° north) and contains high-resolution local data on geomorphological and habitat features. Given that this kind of high-resolution data are rarely associated with broad-scale datasets used in macroecology, this dataset has high potential for helping researchers in tackling a range of biogeographical and macroecological questions, not necessarily uniquely related to arachnology or subterranean biology.

Local- versus broad-scale environmental drivers of continental ß-diversity patterns in subterranean spider communities across Europe.

Macroecologists seek to identify drivers of community turnover (ß-diversity) through broad spatial scales. However, the influence of local habitat features in driving broad-scale ß-diversity patterns remains largely untested, owing to the objective challenges of associating local-scale variables to continental-framed datasets. We examined the relative contribution of local- versus broad-scale drivers of continental ß-diversity patterns, using a uniquely suited dataset of cave-dwelling spider communities across Europe (35-70° latitude). Generalized dissimilarity modelling showed that geographical distance, mean annual temperature and size of the karst area in which caves occurred drove most of ß-diversity, with differential contributions of each factor according to the level of subterranean specialization. Highly specialized communities were mostly influenced by geographical distance, while less specialized communities were mostly driven by mean annual temperature. Conversely, local-scale habitat features turned out to be meaningless predictors of community change, which emphasizes the idea of caves as the human accessible fraction of the extended network of fissures that more properly represents the elective habitat of the subterranean fauna. To the extent that the effect of local features turned to be inconspicuous, caves emerge as experimental model systems in which to study broad biological patterns without the confounding effect of local habitat features.

Two new troglobiont Pygmarrhopalites species of the principalis group (Collembola: Arrhopalitidae) from the West Caucasus.

Springtails of the principalis-group of the genus Pygmarrhopalites from the W Caucasian caves in Abkhazia are described: Pygmarrhopalites dbari sp. nov. from Psyrtskha Cave in Novy Afon and Pygmarrhopalites kovali sp. nov. from caves of Tsebelda Karst Massif. They differ from epigean relatives mainly by troglomorphies: reduced pigmentation, elongated appendages and modified foot complex. These new species as well as a great portion of endemic Caucasian speleofauna have highly restricted distribution and require protection. A new record of Arrhopalites abchasicus Vargovitsh, 2013 in Novoafonskaya Cave is added.

A new species and new records of Arrhopalitidae (Collembola: Symphypleona) from the Republic of Moldova.

Eight species of the family Arrhopalitidae Stach, 1956 are listed from the Republic of Moldova. A new species, Arrhopalites prutensis sp. nov. is described. It belongs to the diversus group of species with 3, 2, 1, 1 anterior setae on dens, possesses neosminthuroid seta on the furca base region-a character rarely noted for the family. The new species is closely related to A. baccettii Dallai, 1969 and A. antonioi Giuga & Jordana, 2013 described from Sicily. Five species of the family are firstly recorded for the country.

Arrhopalites potapovi sp. nov. (Collembola, Symphypleona) from Russia.

A new springtail species of the family Arrhopalitidae, Arrhopalites potapovi sp. nov., is described. It belongs to the caecus species group characterized by 3,2,1,1,1 anterior setae on dens and separates from Arrhopalites caecus (Tullberg) and other congeners by strongly differentiated cuticular spines on sixth abdominal segment, shape of female subanal appendages and foot complex. It was found under the loose bark of trees from two localities along Lake Baikal and it is the second representative of the genus Arrhopalites Börner sensu stricto in Russia.

Cavernicolous Arrhopalites abchasicus sp. nov. (Collembola: Symphypleona: Arrhopalitidae) from the West Caucasus with a key to the World species of the genus.

A new troglobiont species of Collembola, Arrhopalites abchasicus sp. nov., from Psyrtskha Cave in Novy Afon (West Caucasus, Abkhazia) is described. Subdivision of the genus Arrhopalites on diversus, caecus and harveyi groups of species is proposed and identification key to the World species is provided.