Protura (Arthropoda: Hexapoda) in Slovenian caves.

Protura is a small class of Hexapoda, generally poorly known, and rather scarce data on its occurrence in caves are scattered throughout literature on fauna in caves and in some papers on Protura. Although the cave-dwelling fauna is relatively well studied in Slovenia, published records on Protura are rare. In this paper, data on the occurrence and abundance of Protura in Slovenian caves are considered. Various statistical analyses were performed to compare caves with Protura to those without in 60 intensively monitored cavities to detect any differences in the selected environmental conditions. No significant difference was obtained. Samples collected from 15 caves yielded 286 specimens identified to genus or species level. Ten species were identified: Acerentulus confinis (Berlese, 1908), A. rafalskii Szeptycki, 1979*, Acerentomon affine Bagnall, 1912*, A. balcanicum Ionesco, 1933*, A. italicum Nosek, 1969, A. maius Berlese, 1908*, A. meridionale Nosek, 1960, Acerella muscorum (Ionesco, 1930)*, Eosentomon armatum Stach, 1926* and E. transitorium Berlese, 1908*. The seven species marked with an asterisk are new records for Slovenia. Two specimens belonging to an unidentified species of the genus Ionescuellum Tuxen, 1960 were also found. As expected, Protura were most abundant at the cave entrance close to the surface, and none of the species were found exclusively in cavities. This suggests that proturans were introduced passively into the cavities via organic matter and surface soils.