STUDY OF MOLLUSCS’ INFESTATION WITH FASCIOLA HEPATICA IN BRYANSK REGION

The intermediate host of Fasciola hepatica is Lymnaea truncatula mollusk. However, participation of other species of mollusks (L. stagnalis, Galba palustris, etc.) in the development cycle of F. hepatica is not excluded. In this connection, we have studied the distribution of mollusks of these species in the territory of the Bryansk region. The aim of the work was to carry out a study on the invasion of fasciol larvae of mollusks on pastures of trematodiasis-unfriendly farms of the Bryansk region. On farms, the density of mollusks and their species, as well as the dynamics of the infection of mollusks by the partenite stages of F. hepatica, were determined. The work was carried out from May to October 2018 on 3 pastures with an area of 2 to 5 hectares. The study was subjected to mollusks: small pond snail L. truncatula in the amount of from 149 to 151 specimens, ordinary pond snail – L. stagnalis from 10 to 18 specimens, marsh pond snail – L. palustris from 30 to 85 specimens, iushkoviy pond snail – L. auricularia from 4 to 21 specimens. Mollusks were examined every month during the pasture period (May-October) for infection with fasciol larvae by the compressor method. It was revealed that only small pond snail L. truncatula was infested by the larval stages of development of fasciol. The rest of the limneids were free from this trematodase invasion. The small pond snail was infected more intensely in September. The fasciol larvae of the small pond snail were recorded in May, June, August and September; the infection rate was 1.3%, 2.6%, 6.6% and 8%, respectively.