Short-term lab assessments and microcolonies are insufficient for the risk assessment of insecticides for bees

Risk assessment studies addressing effects of agrochemicals on bumblebees frequently use microcolonies. These are queenless colonies consisting workers only in which typically one worker will lay unfertilized male-destined eggs. In the first tier risk for bees, short-term laboratory experiments (e.g. microcolonies) used, results determine whether higher (semi-)field needed. To evaluate suitability microcolonies assessment, a direct comparison between different methods neonicotinoid pesticides acetamiprid and thiacloprid was made: queenright under conditions, long-term field conditions. Here, we demonstrate that from contradict colonies. While negatively impacted gyne production colonies, it had positive effect microcolony size. By contrast, no significant fitness parameters conditions when mostly produced. thus highlight both need long term assessments, allowing evaluation production, reaching erroneous conclusions using The negative colony confirmed where affected reproductives, weight gain, weight, foraging behaviour. For acetamiprid, trend could be shown setup. Therefore, field-realistic setups, allow to forage freely, most appropriate assess sublethal affecting behaviour learning.