The Buzz About Bumble Bees Isn’t Good

— Written By

Wood et al. at Michigan State University | 4/23/2019 | Via ScienceDaily

While many scientists are focused on the decline of honey bees, relatively few study bumble bees. The good news is that a new study provides an estimate on bumble bee population and distributions across Michigan in the past century. The bad news is that these results are dramatically low, and they mirror what’s happening across the Americas, Europe and Asia, too.

Michigan State University led the study, which compared current distributions of bumble bee species across the state to the information gleaned from museum specimens collected as far back as the 1880s. The research, published in the current issue of Ecology, shows that half of the bumble bee species studied have declined by more than 50%.
Bee on Finger

Bee held safely for a portrait. Photo: S. D. Frank.

“Bumble bees are important pollinators of plants across natural habitats, where they help support the seeds and berries that birds and other animals depend on,” said Thomas Wood, MSU entomology postdoctoral researcher and lead author of the study. “They also are effective pollinators of many fruits and vegetables that are important for healthy human diets.”
Take blueberries, for example. Bumble bees are highly efficient pollinators of this leading Michigan fruit crop. To extract the pollen necessary for fertilization, the blossom needs to be shaken vigorously, and bumble bees are expert at vibrating the flowers to shake out the pollen.

“In Michigan, there are 19 species of bumble bees and around 445 species of other bees,” said Wood, who led the study in the lab of Rufus Isaacs, MSU entomologist. “Many of Michigan’s key crops depend on them. In fact, about 50 percent of cherry pollination is carried out by wild bees.”Wood’s team scoured the state of Michigan and compared the distribution of 12 different bumble bee species across the state’s 83 counties before and after the year 2000. Some of the biggest declines include:

  • Rusty patched bumble bee — 100%
  • American bumble bee — 98%
  • Yellow banded bumble bee — 71%
  • Yellow bumble bee — 65%

Find more details of the study here