This book provides an overview of all documented releases of exotic (non-European) invertebrate biological control agents into the environment in Europe and summarizes key information on the target species as well as on the biological control agent released. It covers the period from 1897 to the end of 2009 and is largely based on the BIOCAT database, which contains records of the introduction of insect natural enemies, namely parasitoids and predators, for the control of insect pests worldwide. The content is covered in four sections: Introduction and Summary; European Insect Biocontrol Agents Released in Europe; Weed Control; and Discussion. Providing a representative picture of the history of releases of exotic biological control agents into the environment in Europe, this book is a key resource for researchers and practitioners operating in the areas of biological control and pest management, and those involved in the regulation of the deliberate release of exotic organisms.