During the years 1979-1981 the hirudinean fauna of 9 peat - bog ponds situated to the left of the middle course of the Warta river was studied. The total uf 5634 specimens was collected, representing 15 species. The dominants were Erpobdella octoculata, Erpobdella nioricollis, Glossiphonia complanata. The occurrence of Batracobdella paludosa, Hirudo medicinalis and Haementeria costata in the studied reservoirs is worth noting. The peat-bog ponds are the first locality of Haementeria costata in this type of reservoir in Poland. Dina lineata is the rarest species on the studied area. The high numbers of individuals and the high species diversity of Hirudinea in the studied peat-bog ponds evidence that this type of reservoir, of a rather low biocoenotic diversification, creates favourable conditions for life and development of Hirudinea.
In the year 1986-94 nests of Riparia riparia (L.) were collected from three localites (21 nests near the town of Płoty, 14 from a colony in Pomyłowo and 14 from a colony in Gwiazdowo near the town of Sławno). From 34 (63%) nests 391 specimens of 3 species (Ceratophyllus styx, Ixodes lividus and Oeciacus hirundinis) were collected. Ceratophyllus styx was the dominanting species. It inhabited 32 (59.2%) nests. The highest percentage of nests with ectoparasites and the highest mean number of ectoparasites per nest were recorded in October. The highest mean number of C. styx was observed in the nests in October and the highest mean number of I. lividus - in September. The highest number of nests (28) proved to be inhabited by 1 parasite species.