Following the completion of Brexit, the UK government announced it would be lifting a ban enforceable under the European Union on neonicotinoid insecticides, one of the most commonly used treatments in agriculture worldwide. New research is urging a U-turn on the decision given the damage these treatments can do to already dwindling populations of pollinators.
Like humans, pollinators such as bees need to get sufficient rest in order to function and this new research, published in Scientific Reports, concluded that neonicotinoids could prevent buzzy bees from getting enough Zzzzs.
The negative effects of neonicotinoids on ecosystem-sustaining pollinators such as bees and other winged insects are well documented within the scientific community and yet their use continues to be widespread. They act on nicotinic acetylcholine receptors, which respond to the neurotransmitter acetylcholine, a key neurotransmitter that influences memory and sleep-wake cycles.
The appropriate uptake of acetylcholine by these receptors is essential for efficient foraging and pollination, but the insecticides disrupt this, having an enormously detrimental impact on the pollinators’ health. Using relative concentrations to those employed in agriculture, the research looked at the effects of the European Union-banned neonicotinoids imidacloprid, clothianidin, thiamethoxam, and thiacloprid on the fly species Drosophila’s memory, circadian rhythms and sleep. The UK government has already granted an application to allow the use of a product containing thiamethoxam for the treatment of sugar beet seed in 2021, crops of which have been hit in recent years with beets yellow virus.
Different neonicotinoids influenced the flies’ behavior in different ways; with imidacloprid, clothianidin, and thiamethoxam interrupting natural rhythms, sleep, and learning. While it might be hard to imagine a fly in school, memory and learning are essential for effective foraging and, for eusocial insects such as some bee species, finding your way home. Exposure to the neonicotinoid thiacloprid was found to only have a negative effect on sleep. The study authors warn that the negative influences of neonicotinoids are likely to have detrimental and far-reaching effects on beneficial insects that act as vital pollinators.
"Bees and flies have similar structures in their brains, and this suggests one reason why these drugs are so bad for bees is they stop the bees from sleeping properly and then being able to learn where food is in their environment,” said co-author Dr Sean Rands, Senior Lecturer in the School of Biological Sciences at the University of Bristol, UK, in a statement.
"Neonicotinoids are currently banned in the EU, and we hope that this continues in the UK as we leave EU legislation."