Does Bayer 3-in-1 Kill Bees?

Application

• Bayer 3-in-1 Insect, Disease, and Mite Control comes in a ready-to-use spray and a concentrate. The product is used to controls insects and diseases by spraying it on the foliage of plants being affected by pests. To reduce the chance of harming bees the label suggests that you apply the product when bees are not active around plants in early morning or late evening hours.

Imidacloprid

• The formula contains 0.47 percent of imidacloprid, an insecticide. The University of California Integrated Pest Management Program (UCIPM) recommends using this chemical as a drench to the soil rather than as a foliar spray because of its toxicity to bees and other beneficial insects. But even applied to soil this chemical moves up through the plant and into the flowers, where it can kill bees when they pollinate the flowers. The UCIPM recommends this product only be used during the post-bloom stage on a plant to protect bees.

Tebuconazole

• The product also contains 0.65 percent tebuconazole. This fungicide is one of the most utilized around the world. Bayer 3-in-1 Insect, Disease, and Mite Control integrates it into its formula to control fungi such as powdery mildew and leaf spot. The University of Florida IFAS Extension rates tebuconazole, as “practically nontoxic” to bees and can be used around them with almost no precautions.

Tau-Fluvalinate

• The final active ingredient is tau-fluvalinate, a broad spectrum insecticide and miticide. The spray contains 0.61 percent, and studies vary on its toxicity to bees. Older studies suggest tau-fluvalinate is highly toxic to bees, but newer studies show bees are able to metabolize it and remove it from their system.