But two new studies have shown that a commonly used pesticide disrupts the sleep of bees and flies – with big consequences for important insects.
In one study, researchers looked at the effect of pesticides on bumblebee behavior by giving creatures nectar sugar containing neonicotinoids – one of the most commonly used pesticides – and then tracking their movements in a research arena. of food.
The impact of the pesticide – similar to the amount a bee would encounter in nature – was striking.
“It seems to disrupt the body clock of foraging bumblebees – they foraging much less, more of that foraging occurs at night, and they sleep a lot more during the day. This causes an error in their normal behaviors, ”Kiah Tasman, associate professor in the School of Physiology, Pharmacology and Neuroscience at the University of Bristol, told CNN.
This, she explained, could have serious implications: “It’s quite worrying because other studies and our studies show that the motivation to search for food has decreased.”
Many plants – including the fruits and vegetables that we eat and feed for our livestock – depend on pollinators, like bees, to reproduce.
Nearly 90% of wild plants and 75% of the world’s major crops depend on animal pollination, notes the World Wildlife Fund.
Bees take on a large part of that workload: Pollinators, most often honey bees, are responsible for one in three mouthfuls of the food we eat, according to the United States Department of Agriculture, and are increasing the value of crops in the United States over $ 15. billion every year.
But bees and other pollinators are at risk due to the widespread use of pesticides, habitat loss, the climate crisis and pests, so much so that the chances of spotting the hard-working bumblebee in Europe and Europe. America are down over 30% from the last century.
Tasman warned that the bees are now “quite slow and come out less often anyway.”
“If the time they manage to come out and feed is at night, when flowers are not available, it will greatly reduce their success in collecting the food the colony needs to grow and reproduce,” Tasman, author principal of studies, said.
In a second study, published Thursday, researchers focused their attention on flies – again, exposing them to neonicotinoids, then using infrared beams to monitor how that movement affected.
The results showed that the pesticide works directly on brain cells that run the body clock, which decide when sleep and activity occur during the day – and confuse them.
“It looks like these pesticides are freezing these cells in the form of daytime, so the body doesn’t know if it’s daytime or nighttime,” Tasman said, adding that it is very likely that the same type of mechanism is occurring. in flies also occurs. in bees.
The researchers say their studies can help us better understand how these pesticides affect vulnerable insects.
“It also gives us clues as to what we could study if we were to make more pest-specific pesticides – if we understand exactly how they work on insects, maybe we can make some that only work on pests. “, added Tasman.