How to Achieve Better Chemical Control of Crop Pests and Minimize Pesticide Risk to Pollinators

More than 40 insecticides are currently recommended by extension specialists in the United States for the chemical control of cotton insects. Most pesticides are applied as foliar sprays by airplane or ground sprayers. Pollinators, such as honey bees, may be accidently exposed to insecticide spray. They may take contaminated pollens and nectars back and feed young bees inside hives. Residues of over 150 pesticides were detected at various levels in wax, pollen, bees, and honey found in hives. Studies showed that various lethal and sublethal impact of pesticides might occur. To increase control efficacy and control spectrum against crop pests, tank-mixing is a common practice for farmers to spray two different insecticides together, the mixture may pose additive or synergistic toxicity to pollinators as well. We conducted a variety of assays and showed which insecticide is more toxic and which one is relatively less toxic to honey bee workers, including contact (spray) and oral (feeding) toxicities and the impact on flight of more than 40 pesticides. We also tested numerous insecticide mixtures to reveal any additive and synergistic to honey bees. In addition, the influences of insecticides on six different enzymes were examined. Our data are valuable for guiding insecticide selection in order to maintain effective control of crop pests and minimize risk of insecticides to pollinators as well.