MILWAUKEE — The U.S. Department of Agriculture will spend millions of dollars to help farmers and ranchers improve pastures in five Midwestern states to provide food for the nation’s struggling honeybees under a program to be announced Tuesday.

Commercial honeybees pollinate an estimated $15 billion worth of produce each year. Many beekeepers bring hives to the Upper Midwest in the summer for bees to gather nectar and pollen for food, then truck them in the spring to California and other states to pollinate everything from almonds to apples to avocadoes.

But agricultural production has been threatened by a more than decade-long decline in commercial honeybees and their wild cousins due to habitat loss and pesticide use. Colony collapse disorder, in which honeybees suddenly disappear or die, has made the problem worse, boosting losses over the winter to as much as 30 percent per year.

The USDA hopes to stem those losses by providing more areas for bees to build up food stores and strength for winter. The new program, details of which were provided to The Associated Press ahead of the announcement, will be “a real shot in the arm” for improving bees’ habitat and food supply, said Jason Weller, chief of USDA’s Natural Resources Conservation Service.