Phytopathogens and phytophagous insects coexist within plant communities, often sharing host plants. This study examines how differences in pathogen infection rates influence the species richness, prevalence, and community structure of phytophagous insects at various scales—from individual leaves to entire regions. Using pedunculate oak (Quercus robur) as a model, we explore the impacts of powdery mildew infection across 24 sites in Sweden. Our findings suggest significant effects at local scales, but these do not consistently extend across more significant regional landscapes. This research provides insights into how pathogen dynamics may alter insect community composition and interaction with host plants, highlighting the complex interplay between different trophic levels in forest ecosystems.
In Collaboration with Ayco Tack.