[Occurrence of larvae of Protostrongylidae family in terrestrial snails in the woods of Olsztyn and Silesian districts].

During the years 1992-1993 terrestrial snails were examined to the infection with larvae of Protostrongylidae family in the South and North of Poland. Using compressor method 2267 terrestrial snails from two areas (Pszczyna and Iława) were examined. Collected gastropods belonged to the following species: Arion subfuscus (45 specimens), Bradybaena fruticum (9), Cepaea nemoralis (29), Succinea putris (2147), Zonitoides nitidus (37). Larvae of three species of Protostrongylidae family were found: Elaphostrongylus cervi, Varestrongylus sagittatus and V. capreoli. The highest extensiveness of invasion of Protostrongylidae was noticed in Succinea putris and reached 23.5% in one of plots in the Iława Forest District. The highest intensity of infection was found in S. putris and was as follows: E. cervi up to 150 larvae, V. sagittatus up to 41, and V. capreoli up to 132 larvae. Besides Z. nitidus (1 specimen) there were not noticed any larvae of Protostrongylidae in other species of terrestrial snails. Average extensiveness of invasion of Protostrongylidae in 1992 and 1993 amounted to 7.2 and 9.5% in Iława, and 13.9 and 9.4% in Pszczyna, respectively. The highest percentage of infested gastropods was noticed in June and July. Similar results were obtained in both biotopes examined.