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Changes in the population density of two hard tick species, Ixodes (Exopalpiger) trianguliceps Birula, 1895 and Ixodes persulcatus Schulze, 1930, were examined in 1998-2001, and in 2003-2004 near Gomselga Village (Kondopoga District, 62° 04' N, 33° 55' E) in central Karelia. Data on the abundance of ixodid ticks and the species composition of their hosts in 4 forest sites at different stages of post-felling regeneration (secondary succession), i. e. 7-14, 12-19, 25-32, and 80-87 after logging were obtained. I. persulcatus dominated, comprising 73 % of the total tick number in samples. Regenera- tion of the forest resulted in fluctuations of the population density of two examined tick species: I. (Exopalpiger) trianguliceps (larvae 2.8-5.3; nymphs 1.5-2.2; adults 0-0.09) and I. persulcatus (larvae 4.3-10.6; nymphs 0.6-4.2).

The present study was aimed to examine the specific features of the helminth fauna in insular populations of the bank vole (Myodes glareolus) in the north of the species range. The material was collected in and nearby the Kizhi Archipelago (Lake Onega, 62°1' N 35°12' E) during August 1997, 2005-2007, 2012 and 2013. Small mammals were trapped on 23 islands (varying from 2 to 15,000 ha) and on the mainland. Helminthological met- hods were applied to examine 301 specimens of M glareolus. Fourteen helminth species were found: trematodes--Skrjabinoplagiorchis vigisi; cestodes--Paranoplocephala omphalodes, P. gracilis, Catenotaenia henttoneni, Taenia mustelae, Cladotaenia globife- ra, Spirometra erinacei; nematodes--Trichocephalus muris, Aonchotheca murissylvatici, Hepaticola hepatica, Heligmosomum mixtum, Heligmosomoides glareoli, Longistriata minuta, Syphacia petrusewiczi. The parasites S. vigisi, S. erinaci, H. hepatica and T. muris were identified in the bank vole in Karelia for the first time. Significant differences were detected between the helminth faunas of local insular populations of the bank vole. A distinctive feature of all small islands was that samples from them lacked the widespread pa- rasitic nematode Heligmosomum mixtum. The studies have confirmed the general trends observed in the parasite fauna of most isolated populations of small mammals: a poorer species diversity and high infestation rates with certain species of parasites. The Kizhi Archipelago is characterized by the specific high abundance of regionally rare parasite species (H hepatica, A. murissylvatici), and by the absence of common parasites (H. mixtum, H. glareoli).