Rusty Patched Bumble Bee (Bombus affinis)
This endangered species is native to the Midwestern and Eastern United States and Canada. Its population has declined over 87% in the last 20 years, due to habitat loss, pesticide use, pathogens, and climate change.
Historic & current range of the Rusty Patched Bumble Bee
Historic range of the Rusty Patched Bumble Bees (grey area) in the Midwestern and Eastern U.S. and Canada, in 28 states and 2 provinces. Recently, the Rusty Patched Bumble Bee is only present in 0.1% of its historical range. It has been reported in 13 states, including the Chicago region. High potential zones are in red, low potential zones in yellow, and low potential zones with great uncertainty in light blue. Source: U.S. Fish & Wildlife Service.
Bumble bees are the bee's knees!
Bumble bees are small, yet mighty contributors to our ecosystem. They are important pollinators for flowers and the crops that we eat. Many plants rely on bumble bees for reproduction, such as tomatoes, which only release pollen to the specific vibrations of buzz pollination, unique to bumble bees. The crops they pollinate make up a 3-billion-dollar industry. Worldwide, there are over 20,000 known bee species, including 250 bumble bees, but their populations are declining. If bumble bees were to go extinct, it would be detrimental to flowers, crops, and ecosystems.
Yards as spaces for bee conservation
It is time for us to begin transforming lawns into spaces for conservation. Mowed turfgrass lawns originated in European castles as a sign of prestige and a way to keep out invaders, and to this day they take up a significant portion of land. Turfgrass covers about 40 million-acres, or 1.9% of the surface of the United States, 20-27% of urban green spaces in cities, and 70-75% of cumulative urban green spaces worldwide. Adopting sustainable yard management practices, such as growing native grasses and flowers without chemicals, may be a pathway to restoring and maintaining the health of pollinators and ecosystems.
Host Plants for the Rusty Patched Bumble Bee
By growing any of its 38 native host plants, without pesticides or chemicals, you can supply pollen and nectar for the Rusty Patched Bumble Bee. You would select a variety of host plants with different blooming times to provide foraging resources for the bees throughout their life cycles (March through November). Even one plant might help, especially if your neighbors also grow them, within the 0.6 mile optimal foraging distance of the Rusty Patched Bumble Bee. These plants are common in gardens and benefit other pollinators and the ecosystem.
Color & shape patterns
The Rusty Patched Bumble Bee female workers (center) and males (right) can be identified by the patterns on their backs: a thumbtack-shaped black mark on their thoraxes and a rust-colored patch surrounded by yellow on their abdomens. The queens (left), which are larger, have a black oval-shape on their thoraxes, but no rust-colored patch.
Rusty Patched Bumble Bees are among the earliest bees to emerge from overwintering in the early spring and the last to begin overwintering in the late fall. The queens can typically be seen at the beginning and end of the season when they are either traveling to or from an overwintering site.
More ways to create habitat for bumble bees
1. Eliminate pesticide and chemical use. They are harmful to plants, insects, and people.
2. Grow flowering bee lawns. "Weedy" flowers like dandelions and clovers can provide resources for bees.
3. Mow less (or not at all). Lawn mowers can harm habitat, air quality, and people.
4. Replace turf grass with low-maintenance native grasses. They reduce stormwater runoff and sequester carbon.
1. Leave old rodent holes uncovered to protect potential nesting spots.
"F I G U R E 1 (a) Nest entrance in Milwaukee, Wisconsin, through a hole in the soil in a wooded area; (b) nest entrance in Red Wing, Minnesota, through a hole between the foundation and siding; (c) nest entrance in Minneapolis, Minnesota, through a hole in soil next to concrete steps; (d) Red Wing nest removed from crawl space of home; (e) Minneapolis nest exposed in ground, showing plastic debris intertwined with nest material; (f) male with spatha protruding from abdomen; (g) mating pair; (h) worker/male and queen pupal cell" (Boone et al. 2021) - "Notes from rusty patched bumble bee (Bombus affinis Cresson) nest observations"
2. If you see a bumble bee nest, don't disturb it. Grow host plants close to the bee colony.
1. Protect forest edges or create shady, woodland conditions. Leave the leaves, sticks, and compost.
2. Keep areas of loose soil that are not too wet and will not be trampled on.