Under Review: Data Requirements and Method Development of a New Bee Risk Assessment Scheme for Plant Protection Product Registration.

An up-to-date ecotoxicological risk assessment of plant protection products (PPPs) depends on the constant improvement of risk assessment methods and guidelines, and a thorough evaluation of their impacts. Here, we explain how the risk assessment of PPPs with regard to bees and the authorisation of PPPs is conducted in Switzerland. We further report the design and application of a new method to study homing flights of honey bees using the Radio Frequency Identification (RFID) technique. The new method allowed to address the effects of sublethal doses of two neonicotinoids, thiamethoxam and thiacloprid, on the flight capacities of honey bees. Currently, this study design is under evaluation in an international ring test, in which the Swiss Bee Research centre participates. It is the first test design focussing on sublethal effects of PPPs on honey bees and a draft method will be submitted to OECD to become an official test guideline in the near future. Potential shortcomings and ideas for refinements on the RFID test design are discussed.