Conservation biological control in agricultural landscapes

Summary

Integrating supporting and regulating ecosystem functions provided by several components of biodiversity into cropping systems has been proposed as a promising way to decrease agrochemical inputs and negative environmental impacts while maximizing crop productivity. In this chapter, we illustrate how agroecological knowledge can be used to revisit crop protection and insect pest management using conservation biological control. We review how key management options, from the plant to the landscape level, affect natural enemy communities, insect pest abundance and the level of biological control. We particularly show that maintaining within-field diversity in space and time, reducing nitrogen fertilization or soil tillage as well as using organic farming practices at the farm scale or maintaining seminatural habitats at the landscape scale generally benefit natural enemies, increase biological control and limit pest abundance. We also summarize the body of knowledge of the relationship between natural enemy community structure and the level of pest control. Future research needs and applied perspectives are highlighted.