Studies Link Bee Decline to Common Pesticides 

The enduring mystery of what is behind "colony collapse disorder," the enigmatic ailment that has destroyed honeybee colonies, has confounded scientists for years. But a study published Thursday in the journal Science points to pesticides as the leading factor, a conclusion that quickly set off a new round of debate about what has led to the bees’ decline.

The Associated Press reports the study found that common pesticides called neonicotinoids can confuse honeybees’ brains, rendering them unable to return to their colonies. A second study on bumblebees also published in the magazine found that the chemicals caused the bees to provide too little food to their colonies. (Though in decline, bumblebees have not been affected by colony collapse disorder.)

Neonicotinoids are among the most common insecticides in the United States and abroad, used on almost all U.S. corn and dozens of other crops.   

Both studies came under immediate scrutiny by a top scientist for Bayer Crop Sciences, a leading producer of neonicotinoids, who argued that they used unrealistic doses of the pesticide in their research. The New York Times notes that some unaffiliated scientists backed his concerns. The paper cited widespread scientific disagreement over how important the studies really are, since other research has pointed to a decline in flowers and pathogens that have affected bees.

Other scientists backed the studies and echoed the sentiment of one of the authors, who told the Times that he "personally would like to see them not being used until more research has been done." A bee expert at the U.S. Department of Agriculture called the studies "alarming" and suggested that pesticides may make bees more vulnerable to disease. 

Even the scientist at Bayer Crop Sciences, however, conceded that the studies prompted a "closer look" at how pesticides affect bees. The AP has more on the complicated reaction to the studies.