Spray Toxicity and Risk Assessment of 42 Commonly Used Pesticides to Honey Bees

Frequent foliar sprays on row crops to combat particularly the sucking insects have put honey bee at great risk of direct pesticide exposure, very likely causing sudden disappearance of large number of foraging bees (CCD) and other pollinators. Previous pesticide toxicology studies in honey bees placed more emphasis on pesticide residues at ppb levels within bee hives. Spray toxicity of variety pesticides beyond seed treatments with a few neonicotinoids was largely ignored. In this study, we used spray tower to simulate field spray situation to assess acute toxicity and risk of 42 commonly used pesticides for foliar treatment of row crop pests. Our data revealed a wide range of LC₅₀s among the 42 chemicals, and provided valuable information for guiding pesticide selection in order to minimize the killing of honey bees.