Density-dependent mechanisms in the regulation ofFasciola hepaticapopulations in sheep

Abstract

SUMMARYPopulations ofFasciola hepaticainfecting sheep are regulated by at least 3 density-dependent processes. Parasite deaths due to parasite-induced primary host mortality, fluke fecundity and asexual multiplication in the intermediate snail host,Lymnaea truncatula, vary according to the intensity of infection. Empirical and theoretical evidence is used to assess theextentto which each of these processes in turn affects parasite population numbers.