Blueberry fungicide impacts on honey bee foraging behavior, hive health, and larval toxicity

Honeybees are the principal commercial pollinators of blueberries. Beekeepers have traditionally contracted their bees to pollinate blueberries, and thriving hives once emerged from blueberry pollination services. However, changes in fungicide spray practices in the past two decades may potentially be correlated with declines in bee health. In fact, there is anecdotal evidence that honey bees will ingest freshly sprayed fungicide. We seek to evaluate these reports and determine colony health risks of such behavior. In this talk, I will discuss fungicides used during blueberry pollination and their effects on foraging behavior, colony impacts, and larval mortality. Using flight tunnels to determine forager preference, I conducted behavioral experiments where honeybee foragers were presented with a choice between sugar syrup and sugar syrup laced with a fungicide. I tested commercial fungicides commonly used during blueberry pollination including Quash, Pristine, Ziram, Abound, and Inspire Super. Hive health parameters were taken before and after each experimental run and then compared with larval toxicity bioassays conducted in the laboratory with each fungicide. Findings from my research will help provide recommendations to ameliorate the negative effects of fungicides on honey bees in blueberries.