Protecting Honey Bees from Pesticides - Oklahoma Department of ...

Pesticide ProblemsHoney bees and other insect pollinatorsplay an important role in the productionof many crops in Oklahoma. However,since most crops must be protected frominsect pests and diseases, pesticidepoisoning is the most serious problem forpollinating insects in agricultural areas.Protecting pollinators, especially honeybees, from pesticide poisoning shouldbe part of any pesticide program.The following recommendations can helpminimize bee kills.Pesticides on Blossoms. The blossom isusually the only part of a plant that beesvisit. To avoid killing bees, do not applypesticides hazardous to bees during theblooming period. Treating non-bloomingcrops with a hazardous pesticide whencover crops, weeds, or wild flowers are inbloom within (or near) the treated fieldmay also cause heavy bee losses.Drift of Pesticides. Drift occurs fromnearly all spray or dust applications ofpesticides from a short distance to milesdownwind. Pesticide dusts drift fartherthan sprays. Pesticides applied by planeusually drift farther then those applied byground equipment. Generally, it is lesshazardous to apply pesticides nearapiaries with ground equipment than byplane. Drift can be reduced by applyingpesticides in the evening or early morningwhen the air is calm.Time of Application. Ideally, pesticidesshould be applied when there is no windand when bees are not visiting plants inthe area. In general, evening or earlynight applications are the least harmful tobees.Formulation of Pesticides. Dusts areusually more hazardous to bees thansprays. Wettable powders often have alonger residual effect than emulsifiableconcentrates. Granular pesticides seem topresent very little hazard. Ultra-lowvolume (ULV) formulations of somepesticides are much more toxic thanregular sprays.Toxicity of Pesticides. Most agriculturalpesticides have been tested for theirtoxicity to honey bees. Insecticides affectbees in one or more ways: as stomachpoisons, as contact poisons, and asfumigants. Pyrethroids,organophosphates, and carbamates varyin their toxicity to bees from relativelynon-hazardous to very hazardous,depending upon the individual material orcombination of materials.Herbicides, defoliants, and desiccantssuch as paraquat, MAA, and MSMAreportedly were extremely toxic when fedto newly emerged worker honey bees orwhen sprayed onto older bees in fieldtests.Fungicides seem to cause little trouble forhoney bees.Precautions for Farmers andApplicators• Apply pesticides only when needed.• Use the recommended pesticides atthe lowest effective rate.• Use the pesticide least hazardous tobees that will control the pestinvolved. If all recommendedpesticides are equally hazardous tobees, use the one that has the shortestresidual effect.• Use sprays or granules instead ofdusts.• Make as few treatments aspossible, as repeated applicationsgreatly increase the damage tocolonies.• Do not treat an entire field or areaif local spot treatments willcontrol the harmful pests.