A rusty patched bumble bee at the University of Wisconsin-Madison Arboretum on a dwarf honeysuckle.(Photo: Milwaukee Journal Sentinel)

The rusty patched bumblebee — the first bumblebee ever protected under the federal Endangered Species Act — is emerging from hibernation as it struggles to maintain a tenuous toehold on the landscape.

The bee is known to inhabit only 13 states, including spots across southern Wisconsin that include metropolitan Milwaukee and Madison.

But already in two of the states — Illinois and Minnesota — the protected status of the rusty patched bumblebee has slowed road construction projects.

The U.S. Fish and Wildlife Service officially listed the bee as an endangered species on March 21. The designation triggers a series of protections against knowingly harming the bee or its habitat.

In Illinois, a federal judge halted work on a road project in Kane County, west of Chicago, until at least Tuesday after opponents of the project said the road work could affect the bee.