Quantifying the impact of pesticides on learning and memory in bees

1) Most insecticides are insect neurotoxins. Evidence is emerging that sublethal doses of these neurotoxins are affecting learning and memory of both wild and managed bee colonies; exacerbating the negative effects of pesticide exposure and reducing individual foraging efficiency.
2) Variation in methodologies and interpretation of results across studies has precluded the quantitative evaluation of these impacts that is needed to make recommendations for policy change. It is not clear whether robust effects occur under acute exposure regimes (often argued to be more field-realistic than the chronic regimes upon which many studies are based), for field-realistic dosages, and for pesticides other than neonicotinoids.
3) Here we use meta-analysis to examine the impact of pesticides on bee performance in proboscis extension-based learning assays, the paradigm most commonly used to assess learning and memory in bees. We draw together 104 (learning) and 167 (memory) estimated effect sizes...