Almonds are most U.S. beekeepers’ first stop on their pollination and honey production circuit, so the agrochemicals bees are exposed to in almonds can shape the vitality of their colony for the rest of the year.  We explore the potential for honey bees’ exposure to bee-toxic agrochemicals during almond bloom by utilizing California Department of Pesticide Regulations Pesticide Use Report (PUR) database. We find that overall, use of bee-toxic pesticides in almonds during bloom has decreased since the early 2000s. Almond growers tend to make much fewer applications of pesticides labeled with a precautionary statement during bloom, than those that are not labeled. However, we find that IGRs and fungicides, pesticides not labeled as toxic to bees, are commonly being applied during almond bloom. These types of pesticides can be sublethally toxic to bees but are not labeled as such, presenting potential harm to colonies during almond pollination if growers are not aware of this toxicity. This illustrates the importance of EPA regulations surrounding pesticide labels.  We also find many bee-toxic chemicals are applied prior to almond bloom when bees may already be in almond orchards or surrounding areas. Our findings show that it is imperative for continued communication between almond growers, pesticide applicators and beekeepers to keep honey bee colonies at a low risk of pesticide exposure during almond pollination while maintaining profitable almond production.

Analysis of agrochemical use in California almonds during bloom

2019 Fall National Meeting

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