Common pesticides stop bees and flies from getting a good night’s sleep

Common pesticides stop bees and flies from getting a good night’s sleep - University of Bristol

Just like us, many insects need a decent night’s sleep to function properly, but this might not be possible if they have been exposed to neonicotinoid insecticides, the most common form of insecticide used worldwide, suggests research by academics at the University of Bristol.

Two studies by scientists at Bristol’s Schools of Physiology, Pharmacology and Neuroscience and Biological Sciences have shown these insecticides affect the amount of sleep taken by both bumblebees and fruit flies, which may help us understand why insect pollinators are vanishing from the wild.

Dr Kiah Tasman, Teaching Associate in the School of Physiology, Pharmacology and Neuroscience and lead author of the studies, said: "The neonicotinoids we tested had a big effect on the amount of sleep taken by both flies and bees. If an insect was exposed to a similar amount as it might experience on a farm where the pesticide had been applied, it slept less, and its daily behavioural rhythms were knocked out of synch with the normal 24-hour cycle of day and night."

The fruit fly study published today [21 January] in Scientific Reports, allowed the researchers to study the impact of the pesticides on the insect brain.

As well as finding that typical agricultural concentrations of neonicotinoids ruined the flies' ability to remember, the researchers also saw changes in the clock in the fly brain which controls its 24-hour cycle of day and night.

Access the publications:

‘Neonicotinoids disrupt memory, circadian behaviour and sleep’ by Tasman K, Hidalgo S, Zhu B, Rands SA & Hodge JJL in Scientific Reports

‘The neonicotinoid insecticide imidacloprid disrupts bumblebee circadian rhythms and sleep’ by Tasman K, Rands SA & Hodge JJL in iScience [open access]