S. Mahunka szerk.: Folia Entomologica Hungarica 53. (Budapest, 1992)

FOLIA ENTOMOLOGICA HUNGARICA ROVARTANI KÖZLEMÉNYEK LUI 1992 p. 179-188 Spruce as spider-habitat in urban ecosystem I. By Cs. Szinetár (Received June 15, 1992) Spruce as spider-habitat in urban ecosystem I. - Spiders of 15 families, 40 genera, and at least 60 species were collected from foliage of Picea abies in urban ecosystem, in West Hungary. During the study, Philodromus gfaucinus Simon was identified as a new species to the Hungarian fauna. The species composition of the spiders, and their guild structure based on foraging strategy were found to be very similar to the conditions characteristic of the natural ecosystem. A significant amount of the species found in the study is indentical to the dominant species characteristic of the spruce stands in Northern Europe. In the guild, family and genus, also a significant similarity was found with the spider fauna living on the foliage of gymnosperms in Northern America, too. Besides the mountain dwelling and Northern European species, a number of euryvalent, mostly xerophil, and some synanthropic species are typical of the foliage-dwelling spiders on spruce in the towns. The species abundance and density values stated allow the assumption that spiders on spruce, either as predators or as preys, can play an important part in urban ecosystem. Introduction The structure of environment has an important influence on the habitat preferences of spider species and on the composition of spider communities (Uetz 1991). Greenstone (1984) found a significant correlation between the measure of vegetation complexity and the diversity of web-building species. Spider species diversity and the number of species and guilds are positively correlated with indicators of plant volume and plant foliage diversity (Hatley and Macmahon 1980). Vegetation density is consistently the best predictor of web spider abundance, with prey abundance and microclimate significant additional variables (Rypstra 1986). Most studies have concluded that spider species show highly specific associations with certain plant species and/or structural strata (Uetz 1991). Many studies deal with foliage-dwelling spiders of coniferous trees (Jennings 1987, 1988, Jennings et al. 1990, Gunnarsson 1988, 1990, Palmgren 1972, 1974, 1977, Lehtinen, et al. 1979) Although the basis of spider-coniferous associations is unclear, quite a lot is known about the spiders living on coniferous trees. Spider-conifer habitats are positively correlated with geographic states. Mean conifer-habitat associations did not differ between web spinner and hunter species (Jennings 1987). Corey and Taylor (1989) had similar findings. Gunnarsson (1990) investigated the importance of needle density in determining the abundance and size distribution of spiders on spruce (Picea abies) branches. There was a positive correlation between spider abundance and the proportion of needles, and the size distribu-