What answers can biological control provide to the expectations of an agriculture increasingly concerned with preserving the environment and biodiversity? What applications can it offer to a society concerned with achieving "zero residue" of active molecules in food? This book provides an overview of this complex and specialized scientific subject, which has become a societal issue. An initial assessment reviews the vocabulary, basic knowledge of biology, and basic principles of biological control. Each chapter is complemented by one or two articles written by specialists in the field being discussed: beneficial insects, microorganisms, parasites and parasitoids, plants, aquatic environments, complex systems, inert biocides, etc. Evaluation, possible evolutions, and improvements of biological control methods conclude this innovative synthesis work. It is aimed at teachers, trainers, and students, but also at "lay" readers who are sensitive to the preservation of ecosystems.