An investigation into the synergistic impact of sublethal exposure to industrial chemicals on the learning capacity and performance of bees (360G-Wellcome-094886_Z_10_Z)

Many industrial and household pesticides act on the insect nervous system. However, significant 'off-target' toxicity can also occur in beneficial insects, including bees. The major classes of nervous system insecticide used in the UK act on synaptic transmission. They include potentiation of voltage-gated sodium channels (pyrethroids), inhibition of acetylcholinesterase (organophosphates & carbamates), activation of nicotinic acetylcholine receptors (neonicotinoids) or blocking inhibitory receptor function (thymol, fipronil, avermectins). If present in combination, such agents have potential for additive or synergistic effects. Similarly, fungicides and herbicides have been reported to exhibit unexplained synergy with insecticides. Our multi-disciplinary study will investigate the potential synergistic interactions of industrial agents on bee health using a diverse range of experimental approaches. At the molecular level, quantitative fluorescence assays will use medium throughput screening of cultured bee brain neurons to investigate interactions at the cellular level. These studies will be complemented by brain slice electrophysiology to investigate interactions at the neural network level and the consequences for synaptic plasticity. Results from these screening techniques will feed into behavioural tests of individuals and colonies using a range of learning paradigms in both honeybees and bumblebees. Potential effects of pesticide exposure on bee locomotion, foraging ability and navigation will be determined in laboratory and field experiments. Information generated by the coordinated efforts of all 5 laboratories will be augmented by a survey of experienced amateur beekeepers. Results from this programme will contribute significantly to the development of a coordinated strategy on pesticide use to minimise harmful effects to bees. Finally, we aim to develop several bee cell lines that are desperately needed for the rapid screening of future pesticides.