Résumé
How does spatial heterogeneity affect the dynamics of plant and animal populations? This has been one of the most pervasive questions in ecology for the past few decades. We consider some of the conditions under which spatial heterogeneity in parasitism should not be an important influence on the dynamics of host-parasitoid systems. We suggest that more attention should be given to the measurement of the basic reproductive rates of parasitoids, as well as the partitioning of the finite rate of increase of hosts into density dependent and independent contributions.