Efficacy and economics of shelter habitats for conservation biological control

Provision and manipulation of shelter habitat features within the agroecosystem provide a strategy for enhancing the effectiveness of natural enemies for biological pest control. Evidence from numerous studies indicates that aspects of natural-enemy diversity, abundance and distribution can all be affected by shelter habitats. However, data demonstrating impacts on pest populations and crop yield are few. Accordingly, voluntary adoption of this approach to conservation biocontrol has been limited. We argue that utility of the approach could be enhanced through an improved mechanistic understanding of the relationship between biodiversity of natural enemies and resulting pest control function, including an understanding of the influence of local ecological context and spatial and temporal scale. We also identify the need to consider socio-economic as well as ecological factors to better understand and manage adoption of such conservation biocontrol technologies.