To investigate, scientists looked at two common pesticides: neonicotinoids, which are used to control pests on oil seed rape and other crops, and a group of organophosphate chemicals called coumaphos, which are used to kill the Varroa mite, a parasite that attacks the honey bee.That is not good.
Neonicotinoids are used more commonly in Europe, while coumaphos are more often employed in the United States.
Work carried out by the University of Dundee, in Scotland, revealed that if the pesticides were applied directly to the brains of the pollinators, they caused a loss of brain activity.
Dr Christopher Connolly said: "We found neonicotinoids cause an immediate hyper-activation - so an epileptic type activity - this was proceeded by neuronal inactivation, where the brain goes quiet and cannot communicate any more. The same effects occur when we used organophosphates.
"And if we used them together, the effect was additive, so they added to the toxicity: the effect was greater when both were present."
Another series of laboratory-based experiments, carried out at Newcastle University, examined the behaviour of the bees.
The researchers there found that bees exposed to both pesticides were unable to learn and then remember floral smells associated with a sweet nectar reward - a skill that is essential for bees in search of food.
Dr Sally Williamson said: "It would imply that the bees are able to forage less effectively, they are less able to find and learn and remember and then communicate to their hive mates what the good sources of pollen and nectar are."
Friday, March 29, 2013
Common Pesticides Hurt Bees' Brains