The impact of pyriproxyfen on the development of honey bee (Apis mellifera L.) colony in field

Abstract

Pyriproxyfen (PPN) is an insect growth regulator (IGR) that interferes with insect metamorphosis. Although the side effects of PPN on honey bee larval/adult stages have been studied, the risk to honey bee larvae from PPN residue in the environment is still unclear. In this study, we evaluated the impact of PPN on larval honey bees in field colonies by using an in vivo feeding assay. Oral toxicity to adult honey bees were determined. Finally, influence on royal jelly production was also examined. For in vivo feeding assay, the highest observed PPN treatment caused 67% mortality during pupal stage and in the remaining bees, 62.3% showed abnormal eclosion. Reductions in hatching rate, capping rate and adult emergence rate and increased abnormal eclosion rate were found in the colonies fed with 10ppm PPN syrup. Oral toxicity test revealed that adult honey bees were less susceptible to PPN. Moreover, PPN reduced not only queen cell acceptance rate but also yield of royal jelly in queen cells. These results indicate that PPN has negative impacts on both larval and adult honey bees and royal jelly production, especially under high PPN concentrations. Since PPN is harmful to the development of honey bee larvae and pupae in the natural environment, the issue of honey bee colony contamination by PPN should be addressed.