Integrated Pest Management · Agriculture and Natural Resources
University of California
Best management practices to protect bees from pesticides
Follow these precautions to help protect bees from pesticide poisoning:
- Identify what species of bees are present at the site and learn the specific ways to protect them. Alkali bees, bumble bees, honey bees, leafcutter bees, and other bees vary in their biology, susceptibility to pesticides, and effectiveness in pollinating a particular crop. Methods for protecting bees and promoting pollination can differ depending on the crop and bee species.
- Read labels carefully before deciding which pesticide to apply and follow the product directions. Know and comply with any applicable state and local regulations.
- During prebloom, do not use an insecticide or miticide (acaricide) with a long residual time (extended-residual toxicity) or with systemic (translocated) activity. Avoid pesticides with cautions on the label that read "highly toxic to bees," "toxic to bees," "residual times," or "extended residual toxicity." Residual toxicity to bees varies greatly between pesticide products and can range from hours to a week or more.
- Avoid applying any pesticides to plants that are flowering, particularly insecticides and miticides. Also avoid pesticide drift to nearby blooming plants, including weeds.
- Do not tank mix insecticides or miticides with fungicides for application where plants are flowering, including weeds.
- Do not add adjuvants to fungicide applications during bloom or when there is high honey bee activity in the field unless the product label or pesticide regulations direct an adjuvant should be added.
- If a fungicide or herbicide application is warranted during bloom and allowed by the label and regulations, make the application between sunset and midnight when bees are not active. Be aware that unlike honey bees that return to a hive, some bees spend the night on plants or in soil at the site.
- Do not directly spray bees, beehives, or bee nesting sites with any pesticide. Ensure that the applicator turns off nozzles when near beehives or nesting sites or that hives or bee boxes are removed from the area before application.
- Either remove or cover water sources before spraying pesticide, or supply new, clean water after an application is made.
- Use best management practices for chemigation to prevent bee exposure to pesticide-contaminated water. Chemigation drips or puddles may attract water-collecting bees.
- Prevent the formation and movement of pesticide-contaminated dust when planting pesticide-treated seed or applying pesticide granules or pellets.
- Contact the county agricultural commissioner to learn how to protect bees and the requirements before applying pesticides.
- Remember to keep all parties informed of agricultural sprays, so that beekeepers are always aware of impending applications and applicators are fully informed of the parameters required regarding location, materials, method, and timing of application.
- Use integrated pest management (IPM) to maintain healthy crops and minimize pesticide use.
- Consult the University of California (UC) IPM Bee Precaution Pesticide Ratings to learn how to protect bees when using specific pesticides. Each crop in the UC IPM Pest Management Guidelines also has a table of Relative Toxicities of Insecticides and Miticides to Natural Enemies and Honey Bees in the General Information section.
- Learn what types of bees are present locally and how pollinator management can enhance crop production by contacting the local UC Cooperative Extension office and consulting the California website of the Pollinator Conservation Resource Center.
- See Protecting Natural Enemies and Pollinators for more guidance and precautions.
- Chemigation Safety Measures include avoidance of pesticide-contaminated drips and puddles, University of Minnesota Extension.
- Committed to Healthy Hives in the Field , The Almond Conference 2017.
- Forage Your Way to Better Honey Bee Health , Almond Board of California.
- Fungicides and Their Effects on Non-Target Organisms, Especially Honey Bees, pp. 5–7 in Fungicides, Bactericides, and Biologicals for Deciduous Tree Fruit, Nut, Strawberry, and Vine Crops 2017 , UC.
- How to Reduce Bee Poisoning from Pesticides , Pacific Northwest Extension.
- Insectary Plants as alternate sources of bee nutrition, UC IPM.
- Pollinator Conservation Resource Center, Xerces Society for Invertebrate Conservation.
- Protecting Bees and Other Pollinators from Pesticides, U.S. Environmental Protection Agency.
- Protecting Bees from Pesticides: Now There’s an App for That, Oregon State University.
Adapted from Honey Bee Best Management Practices (BMPs) for California's Almond Industry, Almond Board of California.
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