Several aspects can explain such variability in the results: the studied “pest-antagonist” couple, local context, composition, age and management of the tested plant assemblage, and orchard design. Cultivar and age of producing orchards are
reported to be of little importance to explain the structure of the orchard arthropod community, providing the cultivars are
not insect-resistant and tree architecture is similar. Only juvenile orchards, which are seldom experimented on, differ from older ones. More generally, the effect of a plant manipulation largely relies on the biology of each targeted pest and each natural enemy, and on their interactions, between them and with other species of the arthropod community. We present below understorey and arboreal plant manipulations dedicated to enhancing pest control in orchards. Only plant-based approaches were considered. The manipulation of the habitat of ground-dwelling arthropods, for instance, by mulching the groundcover.