History, current situation and challenges for conservation biological control

Meeting the growing global demand for agricultural products requires the development and use of ecologically-based strategies that will allow sustainable intensification based on ecosystem services. An important component of this approach is conservation biological control. This approach encompasses a variety of management practices that protect natural enemy populations in the agro-ecosystem and enhance their fitness and ultimate impact on pests. It represents an alternative to dependence on pesticides which is associated with environmental damage and risks to human health. The interventions used to achieve conservation biological control are commonly based on managing vegetation patterns at the local scale (e.g. flowering strips that promote parasitoids by supplying nectar) or at wider scale (e.g., woodland to serve as donor habitat for natural enemies). Importantly, such vegetation management also offers scope to provide agriculture with additional ecosystem services as diverse as pollination and carbon sequestration. Despite these attractive features and the success of a small number of conservation biological control strategies, it remains underutilized. We identify as barriers to adoption the relative complexity of conservation biological control and challenges with economic evaluation, as well as perceptions and communication. Climate change is a challenge that will demand the development of flexible strategies that can respond to changes in pest distributions and/or food web structure.