Valuing the tangible benefits that biodiversity provides to farmers may help incentivize conservation in farming landscapes. As insect pests destroy 8-15% of major food crops globally, much of our research focuses on how conserving biodiversity may help mitigate pest infestations. For example, we developed a system for quantifying the value of tropical forests to coffee production, via bird and bat predation on coffee’s most damaging insect pest, the coffee berry borer (Hypothenemus hampei) (Karp et al. 2013 Ecology Letters). In southern Costa Rica, we showed that birds halved borer infestations, preventing US$70-US$310/ha in coffee damage or ~US$10,000 for one small coffee plantation (Fig. 1). Bats, however, fed as intraguild predators and did not prevent coffee damage (Karp et al. 2014 Ecology). We also provided the first evidence that tropical forest increases pest control. After identifying borer-consuming birds with fecal DNA analyses (Karp et al. 2014 SpringerPlus), we showed that patches of forest near coffee farms increased the abundance of borer predators, pest control, and coffee yields. Small, unprotected forest patches provided the most value to farmers, underscoring the need to incorporate farmland forest into conservation planning.
Fig. 1: Excluding insectivorous birds from coffee plants doubled yield loss from coffee’s most damaging insect pest (Karp et al. 2013 Ecol. Lett.; Karp et al. 2014 SpringerPlus). Pictures depict bird exclusion treatments (top), the coffee berry borer beetle (bottom left), and a Yellow Warbler (bottom right), one of the species shown to consume berry borers.
Translating these results into practice requires generalizing findings and packaging them into practical tools for decision-makers. With Rebecca Chaplin-Kramer of the Natural Capital Project, Daniel formed an international working group of ecologists, social scientists, and conservation practitioners to (1) develop decision-support tools for considering pest control in land-use decisions, (2) demonstrate their efficacy with field data, and (3) identify conditions under which habitat would and would not be expected to increase pest control. Team members regularly meet at the national Socio-Environmental Synthesis Center (SESYNC) to exchange ideas and data. To date, the team has compiled and standardized ~150 datasets from >30 countries. We are now working to transform these datasets into a living and growing database that can be broadly applied to both fundamental and applied questions in pest control research. The current version of the database is freely available through PNAS (http://www.pnas.org/content/early/2018/08/01/1800042115) and DRYAD.
- Karp, D.S., R. Chaplin Kramer, and 152 co-authors (In Press) Crop pests and predators exhibit inconsistent responses to surrounding landscape composition. Proceedings of the National Academy of Sciences.
- Tscharntke, T., D.S. Karp, R. Chaplin-Kramer, P. Bátary, F. DeClerk, C. Gratton, L. Hunt, A. Ives, M. Jonsson, A. Larsen, E.A. Martin, A. Martínez-Salinas, T.D. Meehan, M. O’Rourke, K. Poveda, J.A. Rosenheim, A. Rusch, N. Schellhorn, T.C. Wanger, S. Wratten, and W. Zhang (2016) When natural habitat fails to enhance biological pest control- five hypotheses. Biological Conservation 204: 449-458.
- Karp, D.S., R. Moses, S. Gennet, M. Jones, S. Joseph, L.K. M’Gonigle, L.C. Ponisio, W.E. Snyder, and C. Kremen. (2016) Farming practices for food safety threaten pest-control services to fresh produce. Journal of Applied Ecology 53:1402-1412.
- Maas, B., D.S. Karp, J. S. Bumrungsri, K. Darras, C. Huang, C. Lindell, J. Maine, L. Mestre, N. Michel, E. Morrison, I. Perfecto, S. Philpott, C.H. Sekercioglu, R.M. Silva, T. Tscharntke, S. Van Bael, C.J. Whelan, K. Williams-Guillen (2016) Bird and bat predation services in tropical forests and agroforestry landscapes. Biological Reviews. 91: 1081-1101.
- Karp, D.S., S. Judsen, E. Hadly, and G. Daily (2014) Molecular diagnosis of bird-mediated pest control across tropical countryside. SpringerPlus 3: 630.
- Karp, D.S. and G. Daily (2014) Cascading effects of insectivorous birds and bats in tropical coffee plantations. Ecology 95: 1065-1074.
- Karp, D.S., C.D. Mendenhall, R.F. Sandí, P.R. Ehrlich, E.A. Hadly, and G.C. Daily (2013) Forest bolsters bird abundance, pest control, and coffee yield. Ecology Letters 16: 1339-1347.
- Karp, D.S., H. Moeller, and L. Frishkoff (2013) Nonrandom extinction patterns can modulate pest-control service decline. Ecological Applications 23: 840-849.