| Abstract
| - The procedure to assess the risk posed by systemicinsecticides to honey bees follows the European Directivesand depends on the determination of the Hazard Quotient(HQ), though this parameter is not adapted to thesemolecules. This paper describes a new approach to assessmore specifically the risk posed by systemic insecticidesto honey bees with the example of imidacloprid (Gaucho).This approach is based on the new and existing chemicalsubstances Directive in which levels of exposure (PEC,Predicted Exposure Concentration) and toxicity (PNEC,Predicted No Effect Concentration) are compared. PECsare determined for different categories of honey bees inrelation to the amounts of contaminated pollen and nectarthey might consume. PNECs are calculated from data onacute, chronic, and sublethal toxicities of imidacloprid tohoney bees, to which selected assessment factors areapplied. Results highlight a risk for all categories of honeybees, in particular for hive bees. These data are discussedin the light of field observations made on honey beemortalities and disappearances. New perspectives aregiven to better determine the risk posed by systemicinsecticides to honey bees.
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