Ecology of predator-prey and parasitoid-host systems: Progress since Nicholson

This review has three aims. First, we consider Nicholson's contribution to the understanding of predator-prey and parasitoid-host ecology, including his impact on the density-dependence debate in the concert of predator-prey dynamics. Secondly and somewhat selectively, we critically review subsequent developments in understanding with a Nicholsonian focus on theory. Finally, we assess the relevance of theory and Nicholsonian ideas in the practical concert of biological control.