Biological control of the coffee berry borer: Main natural enemies, control success, and landscape influence

Coffee is one of the most important commodities globally and the Coffee Berry Borer (CBB) is its main pest, causing losses of more than half a billion dollars annually. In this systematic review, we quantify the available evidence of successful biological control in coffee agroforestry. There is a recent research trend of switching from the traditional focus on classical biological control to conservation biocontrol, considering a broad range of enemy groups inhabiting the cropping system. We found 19 papers proving CBB biocontrol success in the field and 25 studies suggesting potential biocontrol. Most papers showed effects of fungal infections, followed by papers on ant communities, parasitic Hymenoptera, birds, and nematodes. With respect to local coffee management, arboreal canopy cover providing shade as well as organic practices enhances biocontrol success. Landscape-scale studies are almost missing, although CBB predation by birds can be significant and benefits from the presence of forest patches in the surrounding landscape. Insectivorous birds successfully reduce yield losses by CBB, whereas in many other taxa there is a need for identifying economic impacts of biocontrol. In conclusion, understanding successful coffee management to reduce CBB pest pressure requires more studies on conservation biocontrol, and analyzing the relative importance of local and landscape management for fungal infections as well as for invertebrate and vertebrate predators.