Design and analysis of field studies with bees: a critical review of the draft EFSA guidance

Abstract

The specific protection goal, primary assessment endpoints, acceptable effect thresholds and experimental design proposed in the EFSA update of the bee guidance document are subjected to critical review. It is concluded that the negligible effect criteria were established without sufficient regulatory definition and without convincing scientific argumentation. For the assessment endpoints, effects on hive strength lack temporal definition and the reduction to numbers of bees is inappropriate to evaluate effects. Restricting mortality assessments to homing failure is not theoretically justified and specific criteria were incorrectly derived. The combination of acute effect estimates with models for chronic stressors is biased risk assessment and a temporal basis for the acceptability of effects is missing. Effects on overwintering success cannot be experimentally assessed using the proposed criteria. The experimental methodology proposed is inappropriate and the logistical consequences, in particular those relted to replication and land use are such that field studies are no longer a feasible option for the risk assessment. It may be necessary to explore new lines of thought for the set-up of field studies and to clearly separate experimentation from monitoring.

Keywords: honeybee risk assessment, field study, regulatory guidance