This Special Issue presents articles that combine traditional approaches, novel experimental methods, and advanced techniques, to provide a more in-depth understanding of trophic interactions in biological control. Studies mainly cover behavioural and chemical ecology, molecular ecology using PCR, qPCR and highthroughput sequencing, population genetics, automated deep learning image analysis and photo trapping. Through laboratory and field investigations, articles provide novel insights into host/prey specificity of natural enemies, their multitrophic interactions, and how they behave in space and time. Ultimately, results may be useful for the development of management strategies that aim to improve biocontrol effectiveness against native and invasive herbivorous insects.