The rusty patched bumblebee, a native of Minnesota and Wisconsin that was once common across the Midwest but which has declined rapidly in recent years, was officially declared endangered Tuesday by the U.S. Fish and Wildlife Service.

It's the first species of native bee in the continental U.S. to be placed on the endangered species list.

The chubby bee with a rusty patch on its back once thrived in 28 states across the Upper Midwest and East Coast as well as large parts of Canada. But in the past two decades the bee has disappeared from nearly 90 percent of its historic range - seen in the past 15 years in only 13 states, including Minnesota and Wisconsin, as well as Ontario.

Most of the remaining populations are small and isolated, a problem that could speed the bee's demise.

Experts believe the bee is falling prey to habitat loss, climate change, diseases and, especially, neonicotinoid pesticides - some of the same problems believed to be hurting butterfly populations.

Neonicotinoids are a group of insecticides used widely on farms and in urban landscapes for flowers and gardens. They are absorbed by plants and can be present in pollen and nectar, making them toxic to bees.

The decision to use the Endangered Species Act to try to recover the bee's population comes after years of calls from conservation groups and scientists to protect the native species. Bumblebees are important pollinators for berries, vegetables, clover and native flowering plants. The value of wild bee pollination is estimated at $3 billion annually across the U.S., officials say.

"Our top priority is to act quickly to prevent extinction of the rusty patched bumblebee. Listing the bee as endangered will help us mobilize partners and focus resources on finding ways right now to stop the decline," said Tom Melius, U.S. Fish and Wildlife Service Midwest regional director.

The government's move to list the species as endangered is "the best and probably last hope for the recovery of the rusty patched bumblebee. Bumblebees are dying off, vanishing from our farms, gardens, and parks, where they were once found in great numbers," said Rebecca Riley, senior attorney with the Natural Resources Defense Council, in a statement.

The listing comes after the Xerces Society for Invertebrate Conservation filed a petition to list the rusty patched bumblebee as an endangered species in 2013. Xerces and NRDC filed a lawsuit in 2014 challenging the government's failure to act. The government settled the suit by agreeing in September to list the bee as endangered, action that became final Tuesday.

Rusty patched bumblebees occupied grasslands and tallgrass prairies, many of which have been lost, degraded, or fragmented by conversion to other uses, the U.S. Fish and Wildlife Service said. The bumblebee needs areas that provide food, nectar and pollen from flowers, as well as nesting sites (underground and abandoned rodent cavities or clumps of grasses above ground) and overwintering sites for hibernating queens, namely undisturbed soil.

The bee emerges in early spring and is one of the last bumblebee species to go into hibernation in the fall. Because it is active so long, it needs a constant supply of flowers blooming from April through September.

The federal government in September listed seven species of Hawaiian yellow-faced bees as endangered. They were the first bees in the United States listed under the ESA but are found only found in Hawaii, and they are not bumblebees.

The rusty patched was once among the most common of the 17 bumblebee species found in Minnesota.

What you can do

To help the rusty patched bumblebee and other pollinators such as butterflies and moths,

grow flowers, including flowering trees and shrubs - but make sure they do not contain neonicotinoid pesticides.

Have a mix with something in bloom from early spring through fall. Include native milkweeds for monarch butterflies.

Bumblebees and many other pollinators need a safe place to build their nests and overwinter. Leave some areas of your yard un-mowed in summer and unraked in fall; in your garden and flower beds, leave some standing plant stems in winter.

Provide a pesticide-free environment. You can report sightings of the rusty patched bumblebee to bumblebeewatch.org.

Source: U.S. Fish and Wildlife Service