Pesticide use and large patch size reduce natural pest control potential in vineyards.
Abstract
Promoting natural pest control services through natural enemies in agricultural landscapes offers a sustainable perspective for pest management. Several management options across spatio-temporal scales enhance natural pest control. However, most studies examining how pest control services respond to environmental changes focused on the magnitude of natural pest control across space and often neglect its temporal stability. Consequently, we lack information on the ecological drivers influencing interannual stability of pest control, which is especially important in perennial cropping systems threatened by multiple pests. Here, we used a landscape-scale experiment in southwest France to investigate how local management and landscape context affect the mean level and temporal stability of natural pest control. Our design included paired vineyards in 20 landscapes selected along two orthogonal gradients: organic farming proportion and semi-natural habitat proportion in the landscape. We evaluated natural pest control services annually using eggs of the grape moth Lobesia botrana from 2018 to 2022 (excluding 2020). We predicted that low-intensity farming, with reduced pesticide application and soil disturbance, would enhance predation rates and its stability by benefiting natural enemy communities. Finally, we expected that more complex landscapes, both in terms of composition and configuration, would benefit natural enemy activities and lead to higher levels of pest control. Our analyses revealed that mean daily pest predation decreased with pesticide use and was lower in less complex landscapes, associated with larger patch sizes. However, farming practices and landscape context did not affect predation rate stability over time.