Pseudoscorpiones is an order of arachnids that comprises 27 families, 473 genera, and ca 4000 species worldwide. They occupy diverse terrestrial habitats such as leaf litter, soil, under stones and logs, in mosses and lichens, under the bark of trees and in caves, as well as inside nests of birds, rodents or insects which they often use as phoretic hosts (Benavides et al. 2019). High diversity of pseudoscorpions species is found in the Mediterranean region, which was less harshly affected by Pleistocene glaciation events, and expresses high habitat heterogeneity and diverse ecosystems, including Karstic systems, which harbour species with adaptations to the hypogean environment (Benavides et al. 2019). Israel, as a part of the Levant, is situated at an important zoogeographical crossroad, and therefore harbours a particularly interesting fauna combination of several zoogeographic origins, such as the Palearctic and Ethiopian origins, and one species from the family Menthidae which is known from xeric habitats in America, Australia and Yemen (Beier 1963, Harvey 2013).
Their small size, hidden habitats, and rather complicated taxonomy, lead to paucity of specialists and taxonomic impediment. In Israel all the taxonomic work was done outside the country and relied on random collection as there was never an Israeli specialist who focused on Pseudoscorpions and a methodological survey was never conducted. The only extensive taxonomical study of pseudoscorpions was conducted in Vienna in 1963 by Beier who listed a total of 31 species belonging to 7 families (Beier 1963). Mahnert in Geneva identified and described several additional species (Mahnert 1974, Halperin & Mahnert 1987), and Ćurčić in Belgrade described a new species that was discovered in a chemoautotrophic cave (Ćurčić 2008). Over the years the systematics and classification of pseudoscorpions were revised several times using modern morphological and molecular tools, splitting families, affecting the taxonomic affiliation of species according to the phylogeny and changing their names, resulting in 52 species (including sub-species) belonging to 12 families documented from Israel (Harvey 2013, Benavides et al. 2019, WPC).
As a result of extensive sampling in Israeli caves conducted since 2014 as well as in other natural habitats and agroecosystems, and surveys in natural habitats that suffered ecological disasters, several species new to science were revealed that await scientific description, aside hundreds of specimens that have accumulated at the Israel National Arachnid Collection, at the Hebrew University of Jerusalem (HUJ) waiting for identification.
Dr. Sharon Warburg, in a collaboration with Dr. Danilo Harms, identifed all the pseudoscorpion specimens at the Natural History Collections as well as fresh material collected from beehives, caves and other habitats (over 1500 specimens) according to species, genus and family. Two families were recorded for the first time from Israel leading to a total of fourteen families, and more than 50 species, in addition to several species new to science.