Visiting the Arboretum: All members and visitors need to make a reservation in advance of their visit to the Minnesota Landscape Arboretum. We hope to see you soon!
By Liz Potasek
Pollinator conservationist and biologist Heather Holm was visiting the Arboretum last week for a relaxing walk when she happened on a delightful sight: six Rusty Patched Bumble Bees (Bombus affinis) visiting some Bugbane in our gardens. “I thought it was pretty cool because they were mostly female workers,” she says, noting that they likely have a nest nearby.
The Rusty Patched Bumble Bee is especially significant because they’ve been listed as endangered under the Endangered Species Act, which means the U.S. Fish and Wildlife Service is working to identify, protect and recover Rusty Patched Bumble Bees.
Rusty Patched Bumble Bees have been spotted at the Arboretum, but they haven’t been confirmed on site for a couple of years, says Director of Operations Alan Branhagen, noting that official searches were cancelled due to the pandemic. “We have a team from the U.S. Geological Survey also surveying on the site monthly, but they didn’t report any finds on their first search,” he says.
Rusty Patched Bumble Bees are native to Minnesota and their range used to include the Eastern United States and Upper Midwest. Rusty Patched Bumble Bees typically occupy grasslands, prairies and woodlands, but their population is struggling due to loss of habitat, disease, pesticides and climate change. They emerge in the early spring and are one of the last species to go into hibernation, so they need a constant, diverse supply of blooming flowers from April through September.
Like other bees, Rusty Patched Bumble Bees are important to humans because they play a critical role in pollination and food production.
Holm, who has written several books on pollinators, says there are a few different things homeowners can do to create a habitat for Rusty Patched Bumble Bees and other native pollinators. Focus on planting a diversity of native plant species in yards and gardens to provide food sources and keep some areas of your yard undisturbed to allow for nesting and hibernating. Finally, leave the pesticides on the shelf, she says.