Lawn insecticide impact on bumble bee colonies assessed through realistic field exposures

Growing public concern over the potential for insecticides to intoxicate pollinating insects is motivating the turfgrass industry to seek insecticides that can control pest problems without negatively impacting bees. Lawn care insecticides, in particular, have high potential for bee exposure when applied to weedy lawns in the spring. This study compared impacts of a representative neonicotinoid (clothianidin), combination neonicotinoid-pyrethroid formulation (clothianidin/bifenthrin), and anthranilic diamide (Chlorantraniliprole) on Bombus terrestris colonies foraging on turf with white clover and with or without post-treatment irrigation. The research was conducted in the field in order to ascertain effects of the insecticides on bumble bee colony health with realistic exposures. We measured acute and chronic effects of the insecticides by counting numbers of workers, honey pots, and brood in each hive, assessing queen survival, and testing colony defensive response.