Dr. Murai Éva szerk.: Parasitologia Hungarica 25. (Budapest, 1992)
males, but for 15-17 g animals only, which may be related to sylvicultural factors, although the effect of the chemical weed-killers applied on the development of helminth eggs and thus, invasion by geohelminths has not been investigated. Massive infection of varying prevalence and mean intensity was observed for T. taeniaeformis larva, H. fraterna (only in males) and S. stroma (only in females). The low level of prevalence of Syphacia spp. in young female mice might be due to the Table 4 Mean prevalence of parasitic helminths in Apodemus spp. and M. arvalis Apodemus spp. M. dim. H. msy. C. glo. T tae. H. pol. Murai 1972 7.5* l.f •* *** i 1.0 1.3* 0.5** 0.85 a 4.7* 1.8** Tenora & Murai 1972 8 .0* 1.0* 6.0** Murai & Tenora 1972 1 .0* 5.0* 2.0* Murai 1982 1.5**** 6.2**** Matskási et al. 1990 20.0**** Microtus arvalis Anopl. H. hor. H. asy. T I mus. T. tae. S. nig. H. lae. T. mur. Murai & Tenora 1972 . . . 2.0 5.0 Tenora et al. 1973 10.1 1.0 1.0 1.5 6.1 25.9 15.2 2.0 Murai 1974 6.5 1.0 1.0 1.2 5.0 Mészáros 1977 28.7 6.9 1.4 Mészáros 1980 13.0-23.9 18.5-19 .2 1.5-27.0 2.8-4.9 Murai 1982 1.7 5.6 * Apodemus flavicollis; Apodemus sylvaticus; Apodemus agrárius; Apodemus microps; Anopl. -I- H. horr. 4- H. asy.; H. dim. = Hymenolepis diminuta; H. msy. = Hymenolepis muris-sylvatici; C. glo. = Cladotaenia globifera; T. tae. = Taenia taeniaeformis, Anopl. = Anoplocephalidae; H. hor. = Hymenolepis horrida; H. asy. = Hymenolepis asymmetrica; T mus. = Taenia mustelae; S. nig. = Syphacia nigeriana; H. lae. = Heligmosomoides laevis; T. mur. = Trichocephalus muris earlier leaving of the nest. The helminth fauna of Microtus arvalis produced the expected and usual characteristics, except for Heligmosoides costellatum, which was absent. In view of the data published about the prevalence of helminth infections, the following facts can be established. The prevalences ofH. horrida and H. asymmetrica (1.5%) corresponded to that found in other investigations. The prevalence of T. taeniaeformis larva and T. mustelae (0.5%) was below the value reported in the literature. Infection by H. laevis (8%), 5". nigeriana (8%) and T. muris (0.5%) also proved to be low (cf. Table 4). In spite of the average prevalence of A. dentata (7.5%), P. omphalodes (10%) andi? janickii (9%), general prevalence in M. arvalis remained at a medium level (cf. Tenora et al. 1973, Murai 1974, Mészáros 1980). Studying the dominant species (see Tenora et al. 1973) by the weight category the burden of H. laevis gradually increased, in agreement with data of Kisielewska (1971) and Mészáros (1980), obtained from different localities. The profile of S. nigeriana
