Saturday, Aug. 20, is National Honey Bee Day. Observed on the third Saturday every August, this day educates people about the importance of honey bees and promotes the work of beekeepers.
Various insects, birds, and other animals pollinate plants. Bees, especially honey bees, are the most vital for pollinating food crops. Many California crops rely on bees to pollinate their flowers and ensure a good yield of seeds, fruit, and nuts. Pesticides, especially insecticides, can harm bees if they are applied or allowed to drift to plants that are flowering.
Our mission at the University of California Agricultural and Natural Resources (UC ANR), Statewide Integrated Pest Management Program (UC IPM) is to protect the environment by reducing risks caused by pest management practices. UC IPM developed Bee Precaution Pesticide Ratings to help pest managers make an informed decision about how to protect bees when choosing or applying pesticides.
The bee precaution ratings are based on the reported effects of a pesticide's active ingredient on adult honey bees or their brood. You can find and compare ratings for active ingredients including acaricides (miticides), bactericides, fungicides, herbicides, and insecticides.
Ratings fall into three categories. Red, or rated I, pesticides should not be applied or allowed to drift to plants that are flowering. Plants include the crop AND nearby weeds. Yellow, or rated II, pesticides should not be applied or allowed to drift to plants that are flowering, except when the application is made between sunset and midnight if allowed by the pesticide label and regulations. Finally, green, or rated III, pesticides have no bee precautions, except when required by the pesticide label or regulations.
It is important to note that the bee precaution pesticide ratings are not the pollinator protection statements on the pesticide label.
Each crop in the UC Pest Management Guidelines has links to the bee precaution ratings and provides guidance on how to reduce bee poisoning from pesticides. For more information on protecting bees from pesticides, see UC IPM's Protecting Natural Enemies and Pollinators, and use the Bee Precaution Pesticide Ratings.