Most agricultural pesticides have been tested for their toxicity to honey bees. However, laboratory and field results do not always coincide, due to peculiarities of bee behavior, length of residual life of the pesticide, or the effects of different formulations. Pyrethroids, organophosphates, and carbamates vary in their toxicity to bees from relatively nonhazardous to very hazardous, depending upon the individual material or combination of materials. Some bacteria, protozoans, and viruses that are currently recommended for biological control pose a serious hazard to bees. Herbicides, defoliants, and desiccants such as paraquat, MAA, and MSMA reportedly were extremely toxic when fed to newly emerged worker honey bees or when sprayed onto older bees in field tests.
Fungicides seem to cause little trouble for bees.
Captan at field dosages has caused brood damage. Sex Lures, Attractants, and other Hormones usually cause no problem for bees. Occasionally, a few honey bees and bumblebees have been found in traps containing Japanese beetle lures. Precautions for Farmers and Applicators Apply pesticides only when needed. Use the recommended pesticide at the lowest effective rate.