Exposure of honey bees and other pollinating species to pesticides

  • Anne Alix
  • Mark J. Miles


Background: When considering the risk to bees a thorough understanding of the relevant routes of exposure and the magnitude of exposure is necessary.

Results: Bees forage on plants and in particular flowers to obtain food for themselves and for provisioning their young. Foliar applications during flowering will present the most extreme acute exposure situation. Bees can be exposed to direct spray and also to contaminated pollen and nectar taken back to the colony. Spray applications before flowering may lead to exposure in pollen and nectar if the substance has systemic properties and is persistent. For soil/seed treatments exposure may occur in for systemic products due to translocation from the seed or soil to the upper parts of the plant (e.g. nectar and pollen). Other possible routes for soil/seed treatments include dust-off at sowing and guttation water.

Conclusion: Risk assessment requires that relevant routes of exposure for worker bees, hive bees and young should be considered in the risk assessment for both foliar applied and seed/soil treatment pesticides. The availability of exposure models would assist in the development of honey bee and pollinator risk assessment schemes.

Keywords: honey bee, pesticide, risk assessment, exposure

I. Regulatory issues: honey bee risk for pesticides in Europe