The past year was unusual because more bees died in the summer than in the winter. (Andy Duback/Associated Press)

More than 2 out of 5 American honeybee colonies died in the past year — and, surprisingly, the worst die-off was in the summer, according to a new survey.

Since April 2014, beekeepers have lost 42.1 percent of their colonies, the second-highest loss rate in nine years, according to an annual survey conducted by a bee partnership that includes the U.S. Department of Agriculture.

“What we’re seeing with this bee problem is just a loud signal that there’s some bad things happening with our agro ecosystems,” said study co-author Keith Delaplane at the University of Georgia. “We just happen to notice it with the honeybee because they are so easy to count.”

But it’s not as dire as it sounds. After a colony dies, beekeepers split their surviving colonies and start new ones, and the numbers go up, said Delaplane and co-author Dennis vanEngelsdorp of the University of Maryland.

What shocked them is that this is the first time they’ve noticed bees dying more in summer than winter.

The scientists said mites, poor nutrition and pesticides are to blame for the bee deaths.

— Associated Press