But two new studies have found that a commonly used pesticide disrupts the sleep of bees and flies – with major consequences for important insects.
In one study, researchers looked at the effect of pesticides on bee behavior by giving nectarine-bound nectar sugar to creatures – one of the most commonly used pesticides – and then tracking their movements in the feed arena.
The impact of the pesticide – similar to the amount a bee would encounter in the wild – was strong.
“It seems to disrupt the body clock in search of bees – they eat much less, more of this feeding happens at night, and they sleep much more during the day. This leads to misbehavior of their normal behavior,”
This, she explained, could have serious consequences: “It’s quite worrying because other studies and our own studies show that the motivation to look for food has decreased.”
Many plants – including the fruits and vegetables we eat and feed our livestock – rely on pollinators, such as bees, to reproduce.
Almost 90% of wild plants and 75% of the world’s leading crops depend on animal pollination, according to the World Wildlife Fund.
Bees bear a large share of this burden: Pollinators, most commonly honey bees, are responsible for one in three bites of food we eat, according to the U.S. Department of Agriculture, and increase U.S. harvest values by more than $ 15 billion each year. .
But bees and other pollinators are under threat due to widespread pesticide use, habitat loss, the climate crisis and parasites to such an extent that the chances of spotting hard-working bees in Europe and America have dropped by more than 30% since the last century.
Tasman warned that bees are now “quite sluggish and come out less often anyway.”
“If the time they manage to go out and the feed is at night when the flowers are not available, this will significantly reduce how successful they are in collecting the food the colony needs to grow and reproduce,” Tasman said. lead author of the studies, he said.
In a second study published Thursday, the researchers focused on flies – again, exposing them to neonicotinoids and then using infrared rays to observe how it affects movement.
The results showed that the pesticide works directly on the cells in the brain that control the body’s clock, which decides when sleep and activity occur during the day – and confuses them.
“These pesticides appear to freeze these cells on a daily basis, so the body does not know whether it is during the day or at night,” Tasman said, adding that the same mechanism is very likely to occur in bees.
The researchers say their research could help us further understand how these pesticides affect vulnerable insects.
“It also gives us hints as to what we could study if we needed to make pest-specific pesticides – if we understand exactly how they work on insects, maybe we can make some that work only on pests,” Tasman added. .