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 predators and prey can be attributed to research with insect parasitoids and their hosts. 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, and how this research approach may be beneficial to pest management programs. To date, few studies have quantified prey and predator rates and ranges of dispersal and population dynamics at the patch level—the minimum of information needed to characterize population structure. From host–parasitoid studies with sufficient data, it is clear that the spatial scale of dispersal can differ significantly between a prey and its predators, local prey extinctions can be attributed to predators and predator extinction risk at the patch level often exceeds that of the prey. 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. A prey and its predators can also differ in population structure. At the landscape level, agricultural studies indicate that predator effects on its prey often spill over between the crop and surrounding area (matrix) and can depend strongly on landscape structure (e.g. the proportion of suitable habitat) at scales extending well beyond the crop margins. In light of existing empirical data, predator–prey models 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.

Theory predicts that native plant species should exhibit latitudinal gradients in the strength of their interactions with herbivores. We hypothesize that if an invasive plant species exhibits a different latitudinal gradient in response to herbivores (e.g., a nonparallel gradient), it can create large‐scale heterogeneities in community resistance/susceptibility to the invasive species. We conducted a study of latitudinal variation in the strength of herbivory and defenses of native genotypes ofPhragmites australisin North America (NA) and Europe (EU) and European invasive genotypes in NA. Within NA, we tested whether (1) invasive genotypes are better defended and suffer less herbivory than co‐occurring native genotypes, (2) herbivory and defenses of nativeP. australisdecreases with increasing latitude; and (3) invasive genotypes exhibit either no latitudinal gradient, or a nonparallel latitudinal gradient in herbivory and defenses compared to native genotypes. For the European genotypes, we tested two additional hypotheses: (4) defenses, nutritional condition, and herbivory would differ between the native (EU) and invasive ranges (NA) and (5) latitudinal gradients in defenses and herbivory would be similar between ranges. Within NA, chewing damage, internal stem‐feeding incidence, and aphid abundance were 650%, 300%, and 70% lower, respectively, on invasive than nativeP. australisgenotypes. Genotypes in NA also differed in nutritional condition (percent N, C:N ratio), but there was little support for invasive genotypes being better defended than native genotypes. For the European genotypes, herbivory was significantly lower in the invaded than native range, supporting the enemy‐release hypothesis. Defense levels (leaf toughness and total phenolics) and tissue percent C and percent N were higher in the invaded than native range for European genotypes. Overall, latitudinal gradients inP. australisnutritional condition, defenses, and herbivory were common. Interestingly, chewing damage and stem‐feeder incidence decreased with latitude for nativeP. australisgenotypes in NA and EU, but no latitudinal gradients in response to herbivores were evident for invasive genotypes in NA. Nonparallel latitudinal gradients in herbivory between invasive and nativeP. australissuggest that the community may be more susceptible to invasion at lower than at higher latitudes. Our study points to the need for invasion biology to include a biogeographic perspective.

Nonlethal (trait-mediated) effects of predators on prey populations, particularly with regard to prey dispersal, scarcely have been considered in spatial ecological studies. In this study, we report ...

In theory, the rate of interpatch dispersal significantly influences the population dynamics of predators and their prey, yet there are relatively few field experiments that provide a strong link bet...