Assessing Exposure of Pesticides to Bees

An essential component of an ecological risk assessment is a prediction of exposure of the organisms being assessed. This chapter outlines exposure pathways for the different pesticide delivery methods, both nonsystemic and systemic, and discusses methods used to predict pesticide exposure to honey bees and non-Apis bees. It provides an outline of techniques employed to measure pesticide residues in relevant matrices and discusses higher tier field study designs that are used to refine bee exposure assessments for specific products. The chapter presents perspectives regarding pesticide application technologies that can be employed to mitigate bee exposure, as well as future research needs to further refine exposure assessments for this taxa. Workshop participants agreed that the most significant route of exposure to bees from foliar-applied pesticides is from both contact and oral exposure to contaminated pollen, nectar, and processed food.