More bad news was released this week about honey bees, which have suffered huge losses in recent years.

More than 30% of the honey-bee colonies in the U.S. collapsed this past winter, according to a report by the U.S. Department of Agriculture in collaboration with the Apiary Inspectors of America and The Bee Informed Partnership.

The losses were 42% higher than during the 2011-2012 winter, when 21.9% of colonies died.

Experts noted that the latest losses were in line with the average die-off of 30.5% over the past six years. A loss rate of 15% is considered “acceptable,” according to beekeepers, but 70% of the 6,000 beekeepers surveyed in the study cited heavier losses than that.

Bees have been dying in significant numbers in recent years without explanation. The best that experts and the government can do is give the problem a name: Colony Collapse Disorder.

The USDA says the causes could be parasites, disease, genetics, poor nutrition or pesticide exposure. Environmental and beekeeper groups sued the Environmental Protection Agency last March, seeking to ban pesticides that have been found toxic to bees. The European Commission recently announced it will be banning, across the entire continent, three insecticides believed to be killing Europe’s bee colonies: imidacloprid and clothianidin, produced by Bayer, and thiamethoxam, produced by Syngenta.

There are an estimated 2.62 million bee colonies in the United States.

-Noel Brinkerhoff, Danny Biederman

To Learn More:

Preliminary Results: Honey Bee Colony Losses in the United States, Winter 2012-2013 (by Dennis vanEngelsdorp, Nathalie Steinhauer, Karen Rennich, Jeffery Pettis, Eugene J. Lengerich, David Tarpy, Keith S. Delaplane, Angela M. Spleen, James T. Wilkes, Robyn Rose, Kathleen Lee, Michael Wilson , John Skinner , and Dewey M. Caron; Bee Informed Partnership)

Nearly a Third of Honey Bee Colonies Died in U.S. Last Winter (Agence France-Presse)

Beekeepers Sue EPA over Failure to Protect Bees from Pesticides (by Noel Brinkerhoff, AllGov)

Blamed for Bee Population Collapse, Monsanto Buys Bee Collapse Research Group (by Noel Brinkerhoff and David Wallechinsky, AllGov)