Pesticides May Be Slaughtering Honeybees, Destroying Their Ability to Learn
For the past few years, beekeepers have been forced to contend with a mysterious illness that kills honeybees en masse - and it is apparently getting worse. While experts have not pinpointed the source of these slaughters, it appears likely that pesticides may play a role. If that is true, beekeepers do not just have death to fear for the bee colonies; a recent study has found that a mixture of common pesticides also harms bees' abilities to learn and to make memories.
According to the New York Times, beekeepers have recorded the mysterious disorder, colony collapse disorder, since 2005. Before then, beekeepers, which are transported to farmers who need the honeybees to pollinate their crops, could expect to lose five to 10 percent of their hives. In 2005, that number suddenly swelled to a third. Now, some beekeepers have reported losses of 55 percent.
The impact is not just limited to the beekeepers or the bees themselves. Almond farmers, who rely on bees to pollinate their groves, earn 80 percent of their living from exports. About a quarter of the produce that makes up the American diet, like apples, cranberries and onions, require the use of the honeybee to grow. With the alarming rate of death of the bees, that brings smaller harvests and higher food prices.
Experts are not in agreement about the cause of the deaths. Some blame the prolonged drought occurring in the Midwest. Bee mites that may have become resistant to pesticides and viruses have also been blamed. However, it is pesticides that have come under the most scrutiny. While each pesticide has been approved by government agencies, very little research has gone into the cocktails that many farmers use. Many critics are asking government agencies to perform more research into the nicotine-based neonicotinoids, the chemicals for which can remain in the plant itself for months at a time.
Indeed, it is neonicotinoids, as well as another pesticide, coumaphos, that have come under fire with a recent study published in the journal Nature Communications. In the laboratory, the researchers exposed bees to the amount of pesticide that would be about equal to what they would receive in the wild. According to the BBC, the pesticides targeted the learning center in bees' brains. As a result, as many as 30 percent of honeybees were unable to learn or failed memory tests.
"Pollinators perform sophisticated behaviours while foraging that require them to learn and remember floral traits associated with food," Dr. Geraldine Wright, whose own research prompted the Nature Communications study, said to the BBC. "Disruption in this important function has profound implications for honeybee colony survival, because bees that cannot learn will not be able to find food."