American Bumblebee
Latin Name: Bombus pensylvanicus
Species: Terrestrial Invertebrate
Conservation Status: Not Evaluated
Once the most commonly observed bee species across North America, the population of American bumblebee has declined as much as 90% over the last few decades. Appearing furry, the American bumblebee’s body is covered in dense yellow and black hairs and has brown, transparent wings. The adult American bumblebee is about 0.75-1 inch in length.
Range & Habitat (map)
Though its status has not been classified in South Carolina, the American Bumblebee is considered vulnerable globally as a result of its dramatic decline in numbers, especially across its northern range.
Diet
Bumblebees are pollinators, which means they transport pollen from one plant to another to advance plant fertilization. But, pollination is actually the secondary benefit of their feeding behaviors. Adult bumblebees collect pollen from flowers with the hairs on their legs, carrying it back to their colonies (or dropping it into other flowers along the way). Larvae in the colonies feed on a pollen and nectar mixture called “bee bread.” Unlike honeybees, bumblebees do not convert these plant products into honey.
Life History
Bumblebees live in colonies of 50-100 bees, which follow an annual cycle. In late summer, the queen bee lays eggs that become males and reproductive females or new queens. A the end of summer, they leave the colony, reproduce, and the fertilized females bury themselves to survive the winter. In the spring, the fertilized young queen bee emerges to collect nectar and pollen and to find a new nesting site for her colony. She lays her eggs, which feed on the ‘bee bread’ created from the pollen and nectar. These first eggs grow into female worker bees who continue the work of foraging for food and maintaining the colony. Then, later in the summer, the queen lays eggs that will become the new queens and the males, and the cycle begins again.
Significance
American bumblebees were once the most common species of bumblebees and among the most significant and prolific pollinators for plants across North America. Their rapid decline in numbers is alarming for two reasons: 1) it is an indicator of significant environmental change, and 2) a major concern for the future of our pollination cycle that supports fruit and vegetable production.
Threats & How You Can Help
The major threats to the American bumblebee is loss of habitat and the widespread use of pesticides. We can help the American bumblebee by planting native flowers and shrubs that produce the nectar and pollen these species depend on, as well as eliminating the use of harmful chemical pesticides that poison these bees.
Additional Resources
University of Wisconsin – Madison – https://wisconsinbumblebees.entomology.wisc.edu/about-bumble-bees/life-cycle-and-development/
US Forest Service – https://www.fs.usda.gov/wildflowers/pollinators/pollinator-of-the-month/american-bumble-bee.shtml