IMPLICATIONS OF SPATIAL AGGREGATION OF PA RASITES FOR THE POPULATION-DYNAMICS IN HOST-PARASITE INTERACTION

Some aspects of the widely observed over-dispersed pattern of the dist ribution of parasites within the host population are examined. It has been established in the parasitological literature that most hosts usu ally harbour few parasites, while only few hosts harbour a large propo rtion of the parasite population. Factors that may influence the patte rn of distribution of parasites, the relation between the level of par asite aggregation and the prevalence of infection, and changes in this level of aggregation as a function of host age are analysed. Factors which determine the diversity of species in parasite communities are p resented, and aspects of exploitative and interference competition amo ng parasites and their relations with biological control procedures ar e also considered. Attention is also focused on the regulatory and des tabilizing processes influencing the dynamic behaviour of host-parasit e population interactions.