Neonicotinoids target distinct nicotinic acetylcholine receptors and neurons, leading to differential risks to bumblebees
Abstract
There is growing concern over the risk to bee populations from neonicotinoid insecticides and the long-term consequences of reduced numbers of insect pollinators to essential ecosystem services and food security. Our knowledge of the risk of neonicotinoids to bees is based on studies of imidacloprid and thiamethoxam and these findings are extrapolated to clothianidin based on its higher potency at nicotinic acetylcholine receptors. This study addresses the specificity and consequences of all three neonicotinoids to determine their relative risk to bumblebees at field-relevant levels (2.5 ppb). We find compound-specific effects at all levels (individual cells, bees and whole colonies in semi-field conditions). Imidacloprid and clothianidin display distinct, overlapping, abilities to stimulate Kenyon cells, indicating the potential to differentially influence bumblebee behavior. Bee immobility was induced only by imidacloprid, and an increased vulnerability to clothianidin toxicity only occurred following chronic exposure to clothianidin or thiamethoxam. At the whole colony level, only thiamethoxam altered the sex ratio (more males present) and only clothianidin increased queen production. Finally, both imidacloprid and thiamethoxam caused deficits in colony strength, while no detrimental effects of clothianidin were observed. Given these findings, neonicotinoid risk needs to be considered independently for each compound and target species.
Citation
Moffat , C , Buckland , S T , Samson , A J , McArthur , R , Chamosa Pino , V , Bollan , K A , Huang , J T -J & Connolly , C N 2016 , ' Neonicotinoids target distinct nicotinic acetylcholine receptors and neurons, leading to differential risks to bumblebees ' , Scientific Reports , vol. 6 , 24764 , pp. 1-10 . https://doi.org/10.1038/srep24764
Publication
Scientific Reports
Status
Peer reviewed
ISSN
2045-2322Type
Journal article
Description
This research was funded jointly by BBSRC, DEFRA, NERC, the Scottish Government and The Wellcome Trust, under the Insect Pollinators Initiative (UK) grant BB/1000313/1(CNC).Collections
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