Arachnologische Mitteilungen 56

Arachnids in old oaks 27 Remarkable spider species Linyphiidae Midia midas (Simon, 1884) (Fig. 3a) This species is rare and associated with ancient deciduous trees. It lives in tree hollows, where it builds small horizontal webs (Russell-Smith 2002). It is known to occur from the Iberian Peninsula to Turkey, reaching Denmark, Great Brit- ain and Poland in the north (Nentwig et al. 2018). Within Czechia it has been found in eastern Bohemia around Pardu- bice (Dolanský 1998), South Bohemia (Růžička et al. 1991) and South Moravia near Lednice (Buchar & Růžička 2002, Kubcová & Schlaghamerský 2002). The species is listed in the Czech red list as endangered (Řezáč et al. 2015). Its per- ceived rarity might be partially due to the lack of arachno- logical studies focusing on its habitat, although this habitat – old trees with cavities – has definitely become scarce and threatened. Salticidae Leptorchestes berolinensis (C. L. Koch, 1846) Leptorchestes berolinensis is considered as a rare species, living on vegetation on sun-exposed forest edges, on rock outcrops (Buchar & Růžička 2002), as well as on sun-exposed bark of solitary trees and on wooden fences (Bryja et al. 2005, Machač & Niedobová 2015). It is known to occur widely in Europe, except North Europe and Great Britain (Nentwig et al. 2018).The species is listed in the Czech red list as vulner- able (Řezáč et al. 2015). Theridiidae Dipoena erythropus (Simon, 1881) This species is very rare, living on trees and known within Czechia only from South Moravia (Buchar & Růžička 2002), but it might have been overlooked. It lives on branches in the crowns of deciduous trees, mainly oaks. It is known to occur widely in Europe, except the northern part of Europe (Nen- twig et al. 2018). Four specimens were obtained from FITs in the present study.This species is listed in the Czech red list as critically endangered (Řezáč et al. 2015). Pseudoscorpions (Pseudoscorpiones) In total, 71 specimens belonging to six species from four fami­ lies were identified (Tab. 1). More specimens were collected in pitfall traps than in FITs (Fig. 4b).The most abundant spe- cies, Larca lata , was found exclusively in pitfall traps. Also, all specimens of Allochernes wideri were found in pitfall traps. On the other hand, Apocheiridium ferum (Simon, 1879) and Dendrochernes cyrneus (L. Koch, 1873) were collected only in FITs. Chelifer cancroides (Linnaeus, 1758) and Chernes hahnii (C. L. Koch, 1839) were captured in both trap types. Mark- edly more specimens were present in hollows in trees situated in forest stands than in those growing in meadows (Tab. 1). Remarkably, all pseudoscorpions were collected on live trees, not a single specimen on a dead one (Tab. 1). Remarkable pseudoscorpion species Larcidae Larca lata (Hansen, 1884) (Fig. 3b) This species appears to be rare and vulnerable and is a typi- cal cavity dweller ( Judson & Legg 1996, Ranius & Wilander 2000). It occurs only in Europe, where it has been found in 13 countries until now (Harvey 2013). Recently it was re- ported for the first time from Slovakia and Hungary (Chris- tophoryová et al. 2011a, Novák 2013). Within Czechia it has been found in the Třeboňsko Protected Landscape Area (South Bohemia) and in the Lower Morava Biosphere Re- serve, which covers also the present study site (Ducháč 1993a, Šťáhlavský 2011, Šťáhlavský & Chytil 2013). In the Czech red list, it is listed as vulnerable (Šťáhlavský 2017). Cheiridiidae Apocheiridium ferum (Simon, 1879) This species is distributed in Europe and has also been found in Asian Turkey, Azerbaijan and Uzbekistan (Harvey 2013). Beier (1963) reported that the species lives under tree bark, especially of fruit trees. According to Weygoldt (1966) it oc- curs even in the tightest spaces under bark. Ducháč (1997) reported A . ferum from South Moravia as new for Czechia, without providing information about its habitat. Later it was found in the same region in the village of Lednice (Šťáhlavský & Ducháč 2001) and also close-by at Valtice and Hlohovec, in both cases under Platanus bark (Šťáhlavský &Chytil 2013). Chernetidae Dendrochernes cyrneus (L. Koch, 1873) This species is distributed in Asia and Europe (Harvey 2013). It is one of the pseudoscorpions that regularly occurs in bird nests, but it has also been found under tree bark and Fig. 4: Abundance and species numbers of spiders ( a ) and pseudoscorpions ( b ) in different types of traps. Abbreviations: FIT – flight interception trap, PT – pitfall trap