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Pollinator and Beneficials Toxicity Table


Protecting Honey Bees and Beneficials

  • Choose the least toxic insecticide possible.
  • Do not spray trees in bloom.
  • Apply insecticides in late evening, night, or early morning while bees are not actively foraging. Even if trees are not in bloom, plenty of plants are blooming on the orchard floor or border. Evening applications are generally less hazardous to bees than early morning applications. Bees can be considered to be active when temperatures are above 52°F.
  • Contact the beekeeper or the county bee inspector to make him or her aware of the pesticide application, the type of pesticide, and the area of application.
  • Select herbicide formulations that are the least harmful to bees for roadside and other weed control operations. Tests have shown that at maximum dosage, 2,4-D alkanolamine salts and isopropyl esters and similar herbicides, are more toxic than other forms. Oily formulations seem to be more hazardous to bees. Spraying in late afternoon or evening will also lessen the hazard, since bees will not visit the blooms after they become curled.
  • Blossom-thinning sprays have not been hazardous to bees in orchards. However, Sevin used as a fruit thinner 15 to 25 days past full boom of apples is highly hazardous if cover crop blooms become contaminated.

Understanding the Table

   ++++ = Most Hazardous - Do not apply to blooming crops or weeds.
     +++ = Hazardous - Apply only during late evening.
       ++ = Moderately Hazardous - Apply only during late evening or early morning.
         + = Reasonably Safe - Can be applied at any time.
        --- = No information available.