Bad news keeps on coming for beekeepers.

Amid reports of anti-Zika efforts killing millions of bees throughout the southeast, a new study by the U.S. Geological Survey shows that the increasing demand for biofuels could be taking away habitat best suited for honey bees in some of the nation's top honey-producing states.

Joshua Mayer / via Flickr

With their eyes on high commodity prices and government subsidies, farmers in North and South Dakota have started planting corn and soybeans in areas that were previously grasslands, according to the study, which was published in the Proceedings of the National Academy of Sciences.

Clint Otto, the lead author, and his team looked at the states' land-use trends from 2006-2014. During that time, grasslands were rapidly changed into corn and soybean fields.

The Dakotas are two of the nation's three highest honey-producing states, with more than 18,000 apiaries making up at least 40 percent of the bee colonies in the United States.

But the study showed that beekeepers tend to try to avoid being located near corn and soybean fields, instead choosing the disappearing grasslands.

The study can be used for informing decisions on future land-use management, Otto told The Washington Post, which did a nice write-up on the study.