Dr. Murai Éva szerk.: Parasitologia Hungarica 25. (Budapest, 1992)

common vole, the helminth fauna of the small field mouse (Apodemus microps Kratochvil and RoSicky, 1952) has not been reviewed, and only limited data are available. Murai (1982) emphasized the low infection rate of A. microps with larval taeniids. Heligmosomoides polygyrus was recovered by Mészáros et al. (1981) and Matskási et al. (1990) from different localities in Hungary. Mészáros et al. (1981) also detected Syphacia frederici. Tënora and Mészáros (1975) reported on the occurrence of Syphacia stroma (Linstow, 1884) in Slovakia. On the other hand, a number of helminthological studies have also investigated the tapeworms parasitic in other apodemid species in Hungary (Murai 1972, Murai and Tënora 1972, Tenora and Murai 1972, Tenora and Murai 1980, Tenora et al. 1980). Host-parasite interactions of the above-mentioned micromammalians, however, have not been considered in great detail. Mészáros (1980) discussed the seasonal patterns in the population dynamics of both the common vole and its parasites. Quantitative and qualitative analyses of helminths and their indicator characteristics have been studied, too ( Kisielewska 1971, Tènora et al. 1973). At the same time, no information is available about the seasonal pattern of parasites of the small field mouse and about the host-parasite interaction. Interest has been focused only upon broad patterns of interaction between the wood mouse (Apodemus sylvaticus L.) and a range of helminth species in Britain and Ireland (see Elton et al. 1931, Lewis 1968, Lewis and Twigg 1972, Gregory 1992 for review). The quantitative and qualitative patterns of helminths parasitizing a small field mouse and a common vole population are reported in this paper. MATERIAL AND METHODS Samples of A. microps and M. arvalis were collected by A Demeter using box traps at Babat (Pest county) in an artificially planted pine forest between April 1978 and April 1990. In the framework of sylvicultural activity the forest was treated annually with chemical weed-killers. As shown in the Table 1, the animals were captured mostly in the autumn and in the spring. For each individual, sex, body weight, data of capture and morphological measurements were recorded in the field. Subsequently, the animals were stored at -18 °C until used for parasitological investigation. The helminths were fixed in 5% of hot formalin with saline and preserved in 4% of formalin. Whole mount preparations were stained with iron-carmine, alum-carmine and Ehrlich's haematoxylin for cestodes. Rostellar hooks and eggs were prepared in Berlese solution. Nematodes were translutened in lactophenol solution. Trematodes were not found in the host species. Taking into consideration that the family Hymenolepididae has not been reviewed, the species belonging to it are discussed as s. 1. gen. Hymenolepis. General prevalence and intensity, prevalence and mean intensity of parasitic infection were calculated for weight categories in both sexes of the host species. Studies on the host-parasite interactions will be reported elsewhere (Demeter et al. 1993, in preparation).