D3088: Field relevant exposure of bumble bee (Bombus impatiens) microcolonies to assess impacts of local and landscape sources of pesticides

Pesticides in the environment are a risk for bees during crop pollination because pest control activities at that time can result in direct exposure or foraging on surfaces with high concentrations. Research in Michigan blueberry farms has also identified highly toxic insecticides being collected in bumble bee pollen, presumably from agricultural locations outside blueberry farms. We developed a microcolony experiment to compare the performance of the common eastern bumble bee, Bombus impatiens, when exposed to pesticides originating from locations inside and outside blueberry farms. Microcolonies exposed to field-relevant concentrations of a fungicide applied to blueberries during bloom (fenbuconazole) or to measured concentrations of the insecticide (chlorpyrifos), or to the combination of the two, were compared for their performance. Our results indicate that field-realistic concentrations of pesticides detected at blueberry farms have little direct effect on the common eastern bumble bee.