9: The externalities of pesticide use in California's Central Valley on bees and pollinator-dependent crops

Pesticides are integral components of pest control strategies, but they can also harm pollinators, natural enemies of pests, and other beneficial insects. Pollinators are also needed on many farms, but concerns about the effects of pesticides on honey bees and wild bees have highlighted the challenges of balancing the needs to control pests and support pollinators and other beneficial insects. Making pollinator health a standard component of crop production through Integrated Pest and Pollinator Management (IPPM), but the details of how to implement such a management philosophy have not yet been created and validated. A recent fine-scale, spatially-explicit analysis of pollinator exposure revealed that pesticides found within hives reflect the surrounding use of pesticides in the landscape. In other words, managed bees used to pollinate specialty crops on one field can be exposed to pesticides sprayed on fields within their foraging landscapes. Here, we illustrate how one can combine data on pesticide use, land ownership and bee foraging behavior to quantify the degree to which pesticide used by one landowner creates exposure to their neighbors in California’s central valley. Understanding these externalities can facilitate application of IPPM principles to better protect pollinators while controlling for pests.