L. Forró szerk.: Miscellanea Zoologica Hungarica 12. 1998 (Budapest, 1998)

Farkas, S.: The terrestrial isopod fauna of the Rinya region II. Péterhida

CROATIA Fig. 1. The location of the sampling site Ten pitfall traps were used. All of them were set in a 45-meter-long line transect. The distance between the traps was 5 meters. The transect started inside the oak forest, and perpendicularly crossed the edge, ending in the ruderal vegetation that surrounded the oak wood. The first five traps ("a" - "e") were placed in the vegetation consisting of Quercus robur (80%), Carpinus betulus (10 %), Acer campestre, Corylus avellana, Ulmus sp. (10 % together), understorey: Circaea lutetiana, Hedera helix, Viola sp., Athyrium filix-femina. The vegetation around traps "f

', "g" and "h" consisted of Quercus robur (45%), Carpinus betulus (15%), Robinia pseudoacacia (25%), Cornus mas, Sambucus nigra, Acer campestre (15% together), understorey: Urtica dioica and Athyrium filix-femina). The last two traps ("i" and "j") were surrounded by Robinia pseudoacacia (45%), Sambucus nigra (55%), understorey: Urtica dioica, Conium maculatum, Anthriscus cerefolium, Galium aparine. The data were standardized to analyse seasonal changes in surface activity by the equation: N/dx tr, where N = number of individuals in one sample, d = number of days between two checkings, and tr = number of traps (some traps were destroyed by animals and these were excluded from the analysis). In order to analyse the habitat preference of the species an index was computed what proportion of the total number of trapped individuals of a species was captured by a given trap. The index was calculated in all of the 10 samples. 1. Species composition of the sampling area A total of 1224 individuals were caught during the sampling period. Most of them (565 specimens = 46.16%) were Armadillidium vulgare Latreille (1804) and Porcellium collicola Verhoeff, 1907 (406 specimens = 33.16 %). Subdominant species were Trachelipus rathkii Brandt,1833 (126 specimens = 10.29 %) and Trachelipus ratzeburgi Brandt, 1833 (116 specimens = 9.47 %) (Fig. 2.). Eleven female individuals of Trichoniscidae family (6 specimens of Trichoniscus sp. and 5 specimens of Trichoniscoides sp. = 0.89% together) were trapped also. The globally distributed A. vulgare is very common in Hungary. There Results and discussion