New Xerces Fact Sheet Takes a Deeper Look at Fungicides and Their Effects on Pollinators

By Sharon Selvaggio on 5. August 2019

Sharon Selvaggio

New document reviews the current literature on fungicides and pollinators to help piece together potential risks and how best to respond.

Much of the public discussion about pesticide harm to bees has centered on insecticides—in particular, neonicotinoids. That makes intuitive sense. After all, insecticides are designed to harm insects directly. Fungicides, on the other hand, have long been considered relatively harmless for bees. However, a number of recent studies are calling this assumption into question. Research has shown that some fungicides kill bees on contact. Studies are also documenting that some fungicides synergize with (increase the toxic effects of) certain insecticides. Fungicide exposure has also been linked to higher levels of parasitic and viral infections in honey bee colonies, suggesting that some fungicides may impair a bee’s ability to fight disease.

This diagram shows various interacting stressors that can impact bees and other pollinators, including fungicides. — Fungicides can interact with many other stressors to negatively impact wild and managed bees. For instance, fungicide exposure can alter bee gut microbiomes and foraging behavior, contributing to poor nutrition of individual bees as well as social colonies. (Photo: Bryan E. Reynolds. Graphic Design: Jenni Denekas / Xerces Society and Emily May / Xerces Society)

The Xerces Society’s new fact sheet, Protecting Pollinators from Pesticides: Fungicide Impacts on Pollinators, reviews the current literature on fungicides and pollinators to help piece together potential risks and how best to respond.

Bottom line: Based on the current literature, we recommend taking precautions when responding to disease and pathogen issues. This starts with preventative pest management strategies. Effective strategies against disease include changing planting dates, incorporating effective sanitation practices, and/or crop rotation (while making sure the next crop is not also susceptible to the disease). For more information, please refer back to our fact sheet.

Sharon assists Xerces staff, partners, and the public to reduce reliance on pesticides and understand pesticide risk to invertebrates. Sharon previously worked at Northwest Center for Alternatives to Pesticides, the U.S. Fish and Wildlife Service, and the U.S. Forest Service, and integrates her focus on pesticides with her experience managing natural areas and agricultural lands.