The effect of abiotic stresses on the multi-trophic interactions involving predatory mites under a global change scenario

Predatory mites are key biological control agents in both perennial and greenhouse crops, yet their effectiveness is influenced by anthropogenic and environmental stressors. This thesis investigates how Amblyseius andersoni responds to chemical exposure and thermal stress, integrating field, laboratory, and molecular approaches to inform sustainable pest management. Chapter 1 provides a comprehensive overview of arthropods’ ecological importance and discusses crop protection, integrated pest management, and biological control, with emphasis on predatory mites. Chapter 2 evaluates the impact of pyrethroid applications on mite communities in apple orchards and vineyards, revealing species- and strain-specific sensitivities that underscore the importance of selective pesticide use. Chapter 3 examines how temperature, insecticide exposure, and pollen availability influence survival and fecundity, highlighting the role of alternative food in mitigating combined stressors. Chapters 4 and 5 explore the genetic and molecular bases of pesticide resistance and thermal adaptation, identifying key mutations in the VGSC gene for deltamethrin resistance, regulatory mechanisms for spinosad resistance, and transcriptional remodeling together with HSP and MAPK genes underlying thermal adaptation. Finally, Chapter 6 synthesizes these findings, offering insights for optimizing predatory mites as resilient biocontrol agents under climate change.