EN
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.