By ecoRI News staff
Two decades ago, the rusty patched bumblebee was a common sight, so ordinary that it went almost unnoticed as it moved from flower to flower. But the species, now balancing precariously on the brink of extinction, has become the first bumblebee in the United States — and the first bee of any kind in the contiguous 48 states — to be declared endangered.
The endangered designation is made by the U.S. Fish & Wildlife Service (FWS) under the Endangered Species Act for species that are in danger of becoming extinct throughout all or a portion of their range.
Once common and abundant across 28 states from Connecticut to South Dakota, the District of Columbia and two Canadian provinces, the rusty patched bumblebee has experienced a swift and dramatic decline since the late 1990s. Abundance of the rusty patched bumblebee has plummeted by 87 percent, leaving small, scattered populations in 13 states, including Massachusetts, and one province.
“The rusty patched bumblebee is among a group of pollinators, including the monarch butterfly, experiencing serious declines across the country,” FWS Midwest regional director Tom Melius said. “Why is this important? Pollinators are small but mighty parts of the natural mechanism that sustains us and our world. Without them, our forests, parks, meadows and shrublands, and the abundant, vibrant life they support, cannot survive, and our crops require laborious, costly pollination by hand.”
Like other bees, rusty patched bumblebees pollinate many plants, including economically important crops such as tomatoes, cranberries and peppers. Bumblebees are especially good pollinators; even plants that can self-pollinate produce more and bigger fruit when pollinated by bumblebees. Each year in the United States, insects, mostly bees, provide pollination services valued at an estimated $3 billion, according to the FWS.
Since 2000, rusty patched bumblebees have been reported in Illinois, Indiana, Iowa, Maine, Maryland, Massachusetts, Minnesota, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia and Wisconsin, and Ontario, Canada. Some populations are so small that it’s unclear whether they still exist.
A combination of causes are responsible for the decline in rusty patched bumblebee populations including habitat, disease and parasites, use of pesticides and climate change, according to the FWS.
Melius said there are steps the public can now take to help pollinators: plant native flowers, even in small plots in urban areas, using a variety that will bloom from spring through fall; limit or avoid use of pesticides; foster natural landscapes; leave grass and garden plants uncut after summer to provide habitat for overwintering bees.
The rusty patched bumblebee once lived in grasslands and prairies of the upper Midwest and Northeast, but many of those areas are gone. The bee gathers pollen and nectar from a variety of flowering plants. It emerges in early spring and is one of the last bumblebee species to go into hibernation in the fall. Because it is active so long, it needs a constant supply of flowers blooming from April through September.
Rusty patched bumblebee colonies rely on survival of their queen bee, the only member of the colony that survives the winter. In spring, a solitary queen emerges from hibernation, finds a suitable nest site and lays eggs fertilized the previous fall. Worker bees hatch, and the colony grows. New queens replace the old, all workers die and the cycle repeats.