Mortality of Honeybees (Hymenoptera: Apidae) Exposed to Permethrin and Combinations of Permethrin with Piperonyl Butoxide

Abstract

SummaryA 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.