Cronin, J. T and J. D. Reeve. 2010. An integrative approach to understanding host-parasitoid population dynamics in real landscapes. In E. Ranta, P. Inchausti, and V. Bretagnolle (eds.) Spatial Dimension of Predator-Prey Dynamics. Oxford University Press (in press).
Abstract. Many of our advances regarding the spatial ecology of predators and prey have been attributed to research with insect parasitoids and their hosts. Host-parasitoid systems are ideal for spatial-ecological studies because of the small size of the organisms, the often discrete distribution of their resources, and the relative ease with which host mortality from parasitoids can be determined. In this chapter, we outline an integrated approach to studying host-parasitoid interactions in heterogeneous natural landscapes. This approach involves conducting experiments to obtain critically important information on dispersal and boundary behaviour of the host and parasitoid, large-scale manipulations of landscape structure to reveal the impacts of landscape change on host-parasitoid interactions and temporal population dynamics, and the development of spatially realistic, behaviour-based landscape models. At present, there are only a few study systems for which ecologists have amassed this kind of data. The dividends from such an integrative approach are far reaching, as is illustrated in our research on the prairie planthopper Prokelisia crocea and its egg parasitoid Anagrus columbi that occurs in the tall-grass prairies of the North American Great Plains. Here, we describe the population structure of this system which is based on a spatio-temporal survey of planthoppers and parasitoids among many discretely distributed host-plant patches. We also outline novel approaches to experimentally quantify and model the movement and boundary behaviour of animals in general. The value of this information is revealed in a landscape-level field experiment that was designed to test predictions about how landscape change affects the spatial and temporal population dynamics of the host and parasitoid. Finally, with these empirical data as the foundation, we describe novel simulation models that are spatially realistic and behavior based. Drawing from this integrated approach and case study, we identify key research questions for the future.
Keywords:
Landscape, Anagrus spp., Prokelisia crocea
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