If One Is Bad, Two Are Definitely Worse By Alan Harman
Exposure to a combination of pesticides commonly used in agriculture has a negative impact on bees’ ability to learn, two new UK studies have found.
Researchers at the University of Dundee in Scotland found that the pesticides, used in the research at levels shown to occur in the wild, could interfere with the learning circuits in the bee’s brain. They also found bees exposed to combined pesticides were slower to learn or completely forgot important associations between floral scent and food rewards.
Dr. Christopher Connolly and his team report today in the journal Nature Communications they investigated the impact on bees’ brains of two common pesticides – the neonicotinoids used on crops and coumaphos, used in honeybee hives to kill the Varroa mite.
The intact bees’ brains were exposed to pesticides in the lab at levels predicted to occur following exposure in the wild and brain activity was recorded. They found that both types of pesticide target the same area of the bee brain involved in learning, causing a loss of function. If both pesticides were used in combination, the effect was greater.
“This study shows for the first time the effect of...