Cronin, J. T. and J. D. Reeve. 2005. Host-parasitoid spatial ecology: a plea for a landscape-level synthesis. Proceedings of the Royal Society of London Series B-Biological Sciences 272: 2225-2235.
ABSTRACT
A growing body of literature points to a large-scale research approach as essential for understanding population and community ecology. Many of our advances regarding the spatial ecology of interacting species can be attributed to research with insect hosts and their parasitoids. In this review, we focus on the progress that has been made in the study of the movement and population dynamics of hosts and their parasitoids in heterogeneous landscapes. To date, few studies have quantified the dispersal rate and range of parasitoids and their hosts and obtained even the most rudimentary data on population dynamics at the patch level – the minimal amount of information needed to characterize population structure. For those studies with sufficient data, it is clear that the spatial scale of dispersal can differ significantly between a host and its parasitoids, local host populations can be driven to extinction by their parasitoids, and parasitoid extinction risk at the patch level often exceeds that of the host. It is also evident that populations can be organized as a single, highly connected (patchy) population or as semi-independent extinction-prone local populations that collectively form a persistent metapopulation. Hosts and parasitoids can also differ from each other in population structure. At the landscape level, parasitoid effects on its host can spill over between a patch and the surrounding area (matrix) and can often strongly depend on the structure of the landscape (e.g., the proportion of suitable habitat within the landscape). In light of the limited but existing empirical data, models for hosts and parasitoids are typically spatially unrealistic, lacking important details on boundary responses and movement behaviour within and among patches. The tools exist for conducting empirical and theoretical research at the landscape level and we hope that this review calls attention to fertile areas for future exploration.
Keywords: dispersal behaviour; extinction risk; landscape; metapopulation; spillover effects
