The story below is an excerpt from our March/April 2018 issue. For the rest of this story and more like it subscribe today, log in to read our digital edition or download our FREE iOS app. Thank you!
The listing of the first bumblebee as an endangered species has experts buzzing.
In the mid-1990s, a California entomologist and pollinator specialist at U.C.-Davis noted that two species of bumblebees on the west coast had basically vanished. So he asked his counterparts in the eastern U.S. if they’d seen any similar declines.
“That’s when it appeared that the rusty-patched bumblebee had also disappeared from much of the landscape,” says Rich Hatfield, senior conservation biologist in the endangered species program and head of bumblebee conservation efforts at the Xerces Society.
Originally one of the most common bumblebees in the Blue Ridge area—they once lived in 28 states—the rusty-patched was, in fact, gone from more than 90 percent of its range and was now found in just three Midwestern states.
“There have been two sightings since the 1990s in the state of Virginia,” says Hatfield. “And those have really been the only observations anywhere [in the Southeast] for the last 20 years.”
Like other conservation problems, says Hatfield, “It isn’t like a murder or some crime where there’s a single cause that led to this decline.” But the Xerces Society and other conservation groups point to the emergence of greenhouse tomatoes and the commercial bumblebee industry two decades ago as a primary reason. It is believed that the rusty-patched, along with its California cousins, is uniquely susceptible to a fungus that spread across the country during this process.
“Of course, when you add the fact that we have significant habitat loss throughout much of North America, on top of an increase in use of pretty toxic insecticides over the same time period,” says Hatfield, “you get the sort of soup of factors that just lead to a case that this bumblebee could not overcome.”
In 2017, the rusty-patched became the first bee of any kind (not just bumblebees) in the lower 48 states to be added to the federal Endangered Species List.
Although the recent honeybee decline has drawn far more public attention, the bumblebee plays an equally important role in the cultivation of certain fruits and vegetables. Unlike honeybees and most other insects, the larger, fur-covered bumblebees can regulate their own body temperature; fly in cold weather, even snow, in higher elevations like the Appalachians; and spread pollen in late fall and early spring when it’s too chilly for other bees to be out. They are key pollinators of peppers, blueberries, apples and perhaps most importantly, tomatoes and related veggies through an unusual process called buzz pollination. Grabbing the stamen of a tomato blossom, the bumblebee vibrates its wings at just the right frequency, causing the pollen to shoot out of the plant.
The U.S. Fish and Wildlife Service is now leading a regional search for the rusty-patched to see if, and where, it still exists in the Southeast. No strategies have yet been developed to bring them back. For now, says Hatfield, conservation agencies like Xerces, which petitioned for the Endangered Species listing in 2013, are working to restore habitat with the help of “citizen scientists.”
“[Bumblebees] need lots of bee-attractive flowers from early spring through fall,” he says. “They need a pesticide-free environment. And they need a safe place to build their nests to overwinter. That’s the big picture.”
Bumblebee Conservation: How to Help
• Plant flowers the insects like, such as coreopsis, bee balm, blazing star, coneflower and lobelia.
• Buy the plants from reputable nurseries that don’t pre-treat them with harmful systemic insecticides.
• If you must use a pesticide to control other insects, choose the least toxic. Try soapy water and other home remedies first.
• “Be a little bit lazy in your yard,” says Rich Hatfield, senior conservation biologist in the endangered species program at the Xerces Society. Set aside brush piles for the bumblebees to nest and leave one or more patches of grass unmowed.
• Help track native species through bumblebeewatch.org, which encourages the public to identify bees, including endangered species, in their own gardens and yards.