TOXIBEECOG · TOXIcology & BEE COGnition : Uncovering the Impacts of Pesticides on Honey Bee Cognition

Honey bees play a key role in diverse ecosystems due to their pollination services. This activity depends on the capacity to learn and memorize floral olfactory and visual cues, thus bees are not only able of simple associative learning but also master higher-order forms of learning. Reversal learning (RL) and Negative Patterning Learning (NPL) help bees to effectively exploit complex environments. Foraging leads to pesticidal exposure, contributing to the concerning decline of bee health. Several studies revealed the adverse effects of pesticides on bee health, but their impact on higher-order cognition is still unaddressed. Focusing on this vital form of behavioural plasticity is important as it could reveal pesticide impairments at unsuspected low doses, as compared to simpler and more robust learning tasks (e.g. Differential Learning, DL). Thus, it is relevant and timely to explore the impact of pesticides on higher-order cognition in bees, focusing on both classic (neonicotinoid) and newer (sulfoxamine) common insecticides. Here, we aim to investigate the impact of field-realistic exposure to a neonicotinoid and a sulfoxamine on three ecologically relevant learning tasks of varying cognitive complexity (DL, RL, NPL). While DL is a case of simple associative learning, RL involves transient stimulus ambiguity and requires learning flexibility; NPL is a case of non elemental learning as stimulus ambiguity is constantly present during the learning task. These problems will be studied in the olfactory domain, using olfactory conditioning, and in the visual domain, using a virtual reality approach. These protocols will be combined with various forms of pesticide exposure. We will determine how pesticides affect higher-order problem-solving in bees and will provide insights into the underlying neural mechanisms of pesticide effect on learning and memory. Our project represents an innovative initiative aiming at bridging the gap between cognition and ecotoxicology.