Mortality of honeybees (Hymenoptera: Apidae) exposed to permethrin and combinations of permethrin with piperonyl butoxide.
James R. Hagler, Gordon D. Waller And Brad E. Lewis
A laboratory study was conducted to test the pyrethroid insecticide, permethrin, separately and in combination with piperonyl butoxide (PB) at ratios of 1 part insecticide to 4 and 9 parts PB. Foraging honeybees, Apis mellifera L., were exposed to treated filter paper to determine toxicity and synergistic effects between the binary mixtures. Mortality was recorded 48 h after treatment. Permethrin used alone was highly toxic to the bees. PB synergized permethrin at both ratios, increasing the efficacy of permethrin, 9-fold. Combinations of permethrin and PB may merit testing in field situations to determine the actual hazard to honeybees.