EFFECT OF SEASONAL HOST REPRODUCTION ON HOST-MACROPARASITE DYNAMICS

The impact of seasonal host reproduction on the population dynamics of host-macroparasite interactions is considered. We modify the classic Anderson and May model so that parameters associated with host reprodu ction are periodic functions of time with a period corresponding to a year. This allows us to compare our findings with those already well d ocumented. If, in the absence of any seasonality, a stable steady-stat e solution exists annual reproduction gives rise to stable annual popu lation cycles. Moreover, the parameter domain for which there is stabi lity is increased by the seasonality. However, if the life span of the free-living stages is reasonably long, and the continuous model has l imit cycle solutions, complex behavior can be observed in the seasonal ly forced case. Results also indicate that if seasonal effects are ign ored, regulation of the hosts by the parasite population is overestima ted.