Guest blog post by Pavol Purgat
For the first time in Slovakia, the dwarf spider Walckenaeria stylifrons and crab spider Spiracme mongolica were discovered on sand dunes in Záhorie Protected Landscape Area, on localities that serve as a military complex, used by the native Slovak army. Moreover, the spider W. stylifrons was found in a wine-growing region near the historical town of Modra.
Scientists Pavol Purgat, Dr Peter Gajdoš, Natália Hurajtová, Institute of Landscape Ecology-Slovak Academy of Sciences, Slovakia, and Dr Katarína Krajčovičová, Dr Adrián Purkart, Ľubomír Volnár, Faculty of Natural Sciences-Comenius University in Bratislava, Slovakia have published their paper, where they introduce two new spider species for Slovakia, in the open-access journal CheckList, the journal of biodiversity data.
European continental sand dunes, characterized by high ground temperature, high temperature fluctuations and movement of sand masses, belong to the rare, climatically extreme areas resembling deserts. In Europe, lowland sandy grassland habitats are considered to be among the most endangered and are often the subject of nature conservation.
The researchers decided to understand the spider assemblages living in such extreme habitats in Western Slovakia. During 2018–2019, the study sites were chosen and co-called pitfall traps hidden in the ground were used to collect spiders.
Among other collected species, two spiders were found for the first time in Slovakia. The dwarf spider W. stilifrons is recorded from 15 European countries and it is known from Eastern England to Eastern Germany in the north, and from the Iberian Peninsula to the Crimea and Cyprus in the south. Within Central Europe, the species has so far been known from Austria, Germany and Switzerland. The crab spider S. mongolica is known from Serbia to the European part of Russia. Its distribution in Asia extends from Central Asian part of Russia, Azerbaijan, Kazakhstan to Mongolia and China. In China it is known only from Western Inner Mongolia and Xinjiang region.
Upon the detailed examination of male copulatory organs, the researchers found out that one of the species shares characters typical for the genus Spiracme, in consideration of that a new combination Spiracme mongolica for the spider previously known as Xysticus mongolicus was suggested.
In conclusion, the authors assume that W. stilifrons can live elsewhere in Europe. The rarity of the species may be related to the occurrence of adults, especially in the winter months, as most researchers are focused only on the growing seasons. The occurrence of S. mongolica in sand dunes in Slovakia confirms this species preference for dry habitats. The new finding of S. mongolica is the most known westernmost.
Purgat P, Gajdoš P, Purkart A, Hurajtová N, Volnár Ľ, Krajčovičová K (2021) Walckenaeria stilifrons and Spiracme mongolica (Araneae, Linyphiidae, Thomisidae), two new species to Slovakia. Check List 17 (6): 1601-1608. doi: 10.15560/17.6.1601