Public Comment on Rusty Patched Bumble Bee Habitat
Wisconsin's Green Fire, January 27, 2025

Working to Protect Biodiversity
Wisconsin’s Green Fire submitted public comment to the United States Fish and Wildlife Service (USFWS) in late January 2025. Our comment letter expressed support for the designation of critical habitat for the rusty patched bumble bee (Bombus affinis). The USFWS called for comments on the proposed rule to designate this critical habitat.
The rusty patched bumble bee is listed as endangered under the Endangered Species Act at both the federal level and state level. Wisconsin is one of only nine states and one Canadian province where the rusty patched bumble bee is known to survive.
Below, you can read the contents of our letter, as well as in PDF format here. One of WGF’s wildlife experts, Kerry Beheler, prepared the contents of our comment letter to the USFWS. We submitted the letter to the Federal Register during the public comment period that ended January 27, 2025.
Wisconsin’s Green Fire – Public Comment on Critical Habitat for Rusty Patched Bumble Bee (Bombus affinis)
Docket Number: FWS-R3-ES-2024-0132
Wisconsin’s Green Fire: Voices for Conservation (WGF) requests that the United States Fish and Wildlife Service (USFWS) designate critical habitat for the endangered rusty patched bumble bee (Bombus affinis) under the Endangered Species Act. Most of the proposed critical habitat designation is on private land within urban areas. If finalized, the critical habitat designation will not affect activities by private landowners unless the activity is funded or authorized by a federal agency. WGF submits these comments for the federal record in support of critical habitat designation for the rusty patched bumble bee.
WGF is an independent nonpartisan organization that supports the conservation legacy of Wisconsin by promoting science-based management of its natural resources. More information about WGF can be found at https://wigreenfire.org.
The rusty patched bumble bee was listed as a federal and Wisconsin state endangered species in 2017. It was the first bee in the continental United States to receive Endangered Species Act protection. Wisconsin remains one of only nine states and one Canadian province where the rusty patched bumble bee has been found in recent years. Until the mid to late 1990s, the rusty patched bumble bee was abundant across a broad geographic range. The bee’s abundance and distribution has declined by about 87 percent, and its population has been reduced to 8 percent of its historical extent.
Before listing in 2017, the bee experienced a widespread and abrupt decline. Evidence suggests a synergistic interaction between an introduced pathogen and pesticide exposure (specifically, insecticides and fungicides). Additional population threats include habitat loss and degradation, small population dynamics, and the effects of climate change.
The rusty patched bumble bee is one of 20 Wisconsin native bumble bee species. The bee has been found in 21 Wisconsin counties, with most observations from the southern third of the state. One area of critical habitat is the Southwest Wisconsin Grassland and Stream Conservation Area (SWGSCA), a partnership between local, state, federal, non-profit organizations, landowners, and individual citizens all working together to sustain functional grasslands, savannas, and stream habitats. Within the SWGSCA is the Military Ridge Prairie Heritage Area (MRPHA), an area identified by the Nature Conservancy as critical for the protection of Midwest prairie remnants and area-sensitive species, including the rusty patched bumble bee.
The rusty patched bumble bee is an important pollinator of prairie wildflowers, and Wisconsin agricultural crops including cranberries, blueberries, apples, alfalfa and numerous others. In 2015, Wisconsin’s Department of Agriculture, Trade and Consumer Protection led the development of the Wisconsin Pollinator Protection Plan, which provides voluntary actions that homeowners, gardeners, farmers and pesticide applicators can take to protect pollinators including the rusty patched bumble bee.
WGF commends the USFWS for moving forward on this important decision to designate critical habitat for the rusty patched bumble bee. WGF looks forward to continued work to ensure that the rusty patched bumble bee is protected and recovered. We believe no species is too small to support the security of our food systems. No species is too small to protect biodiversity and a healthy functioning ecosystem.
More information on the rusty patched bumble bee can be found at these links:
- Bully for Bees, Wisconsin Department of Natural Resources:
https://dnr.wisconsin.gov/sites/default/files/topic/EndangeredResources/bullyforbees.pdf - Rusty Patched Bumble Bee, Xerces Society:
https://www.xerces.org/endangered-species/species-profiles/at-risk-bumble-bees/rusty-patched-bumble-bee - Pollinator Protection, Wisconsin Department of Agriculture, Trade and Consumer Protection:
https://datcp.wi.gov/Pages/Programs_Services/PollinatorProtection.aspx - South West Wisconsin Grassland and Stream Conservation Area, Wisconsin Department of Natural Resources:
https://dnr.wi.gov/topic/Lands/grasslands/swgrassland.html - Wisconsin Department of Natural Resources Natural Heritage Inventory working list:
https://dnr.wi.gov/topic/nhi/wlist.html - Wisconsin Wildlife Action Plan: Habitats. Wisconsin of Natural Resources. https://dnr.wi.gov/files/pdf/pubs/nh/nh0983_4_0-3.pdf.
- Rusty Patched Bumble Bee, U.S. Fish & Wildlife Service: https://www.fws.gov/species/rusty-patched-bumble-bee-bombus-affinis
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