New research has found bees struggle to fly in a straight line if they've been exposed to pesticides, which makes it harder for them to find their way back to the hive.
The research also found that pesticide-exposed bees tended to have an elevated proportion of dead cells in parts of the brain's optic lobes, important for processing visual input. Photo: 123RF
Released by The University of Oxford the paper says honeybees have an innate ability to orient themselves back onto a straight line when blown off course.
Researchers tested this ability with walking bees by putting them in front of video screens that tricked them into thinking they had moved off course.
Lead author Dr Rachel Parkinson said bees contaminated with modern pesticides were worse at correcting themselves.
"Here we show that commonly used insecticides like sulfoxaflor and the neonicotinoid imidacloprid can profoundly impair the visually guided behaviour of honeybees.
"There was a huge effect, the bees that were treated with the insecticides were unable to follow the direction of visual movement so they weren't able to orient themselves properly.
"Our results are reason for concern because the ability of bees to respond appropriately to visual information is crucial for their flight and navigation, and thus their survival," she said.
The research also found that pesticide-exposed bees tended to have an elevated proportion of dead cells in parts of the brain's optic lobes, important for processing visual input.
"To fully understand the risk of these insecticides to bees, we need to explore whether the effects we observed in walking bees occur in freely flying bees as well.
"The major concern is that, if bees are unable to overcome any impairment while flying, there could be profound negative effects on their ability to forage, navigate, and pollinate wildflowers and crops."