Researchers racing to find the cause of Colony Collapse Disorder (CCD), which has been killing off honeybees in much of the U.S. and Europe, are zeroing in on the culprit. And — surprise — mites are apparently no longer suspects. But cold winters may be accomplices to the crime. Studying colonies of honeybees (Apis mellifera L.) at three locations in central Massachusetts during the 2012-13 winter, researchers found that two widely-used pesticides were directly responsible for the hive abandonment and death of several colonies. Comparing their results to previous research, the scientists noted that colder winters may aggravate the negative effects of the pesticides.
For the study, appearing today in the Bulletin of Insectology, researchers monitored 18 bee colonies — six in each location — from October 2012 through April 2013. A third of the colonies were exposed to low doses of the pesticide imidacloprid, while another third were exposed ...