(NAFB.com) – New research from the USDA’s Agricultural Research Service sheds light on the causes behind the catastrophic honeybee colony losses reported by commercial beekeepers this year. The findings point to an alarmingly high level of viral infections caused by Varroa mites that have resistant genes to a common treatment. The study analyzed samples from six major commercial beekeeping operations affected by the losses and provided the most detailed evidence of the biological factors behind the widespread die-offs. Collectively, the operations reported losses averaging over 60 percent of their colonies just as they were being staged for California’s almond pollination season. All of the Varroa mites collected tested positive for a genetic marker linked to resistance to Amitraz, the most commonly used mite treatment in commercial beekeeping. “We can’t keep relying on a single line of defense against Varroa mites, which are quickly evolving,” said Patty Sundberg, President of the American Beekeeping Federation.
