NEW DATA ON SPIDER FAUNA FROM NORTHERN SERBIA

During two years of research on the epigeic fauna in agroecosystems of northern Serbia, which was conducted as a part of SEE-ERA NET PLUS project no. 51, 5488 spider specimens were collected at three fields with oilseed rape (Brassica napus var. oleifera), turnip rape (Brassica rapa x chinensis) and winter wheat (Triticum aestivum).as subsequent crop.at Stari Žednik (Vojvodina). A total of 62 species from 15 families were identified. Pardosa agrestis and Xysticus kochi were the dominant species in the studied fields. Spider families with significant presence were Lycosidae, Linyphiidae, Thomisidae, Gnaphosidae, Theridiidae and Philodromidae. Seven species are new to the spider fauna of Serbia.


INTRODUCTION
Data on spider fauna in northern regions of Serbia are still insufficient, from crop fields in particular.The richness depends, however, on the degree of exploration by arachnologists.Most investigations were conducted in area of Fruška Gora mountain by Chyzer and Kulzyński (1897), Sisojević and Miller in 1978and Grbić and Savić from 2005to 2009(Grbić and Savić, 2010).Few faunistic studies were carried out in other parts of Vojvodina by Chyzer andKulzyński (1894 and1897) and Marinković in 1959 (Deltshev et al. 2003).In this paper we present a brief report on the spider fauna from arable fields in northern Serbia adjacent to the village Stari Žednik in the Vojvodina.

MATERIAL AND METHODS
Spiders were collected from October 2010 until June 2012, during the growing period of oilseed rape (Brassica napus var.oleifera) including turnip rape (B.rapa x chinensis) trap crop strips, and on winter wheat (Triticum aestivum), grown in crop rotation with oilseed rape from October 2011 until June 2012.The research was carried out as a part of the SEE-ERA-PLUS-NET project no.51, at the locality Stari Žednik near Subotica, Serbia (Map 1).Spider specimens were sampled by epigeic and endogeic pitfall and emergence traps.
Pardosa agrestis is the most common agrobiont spider in the studied agroecosystem.However, this species is not agrobiont in Western Europe.It gains increasing dominance in central Europe along a NW-SE gradient (Blick et al. 2000), probably as a result of adaptation to climatic conditions (Samu et al. 2011).
Other species (Erigone dentipalpis, Meioneta rurestris and Xysticus kochi) belong to the group of typical central European agrobiont spider species.Trichoncoides piscator and Robertus arundineti are inhabitants of open habitats, including cultivated fields (Kalushkov et al. 2008, Hula et al. 2009).Xerolycosa nemoralis is regarded as a forest species, but is not uncommon in open areas and can be found in arable fields (Urák et al. 2010).
Spider taxa, new to Serbian fauna are already registered in adjacent regions and are widely distributed  in Europe, thus their previous absence in Serbia can be explained by the insufficient research data.

Fig. 3
Fig. 3 Composition of dominant spider families at the crop fields near Stari Žednik locality