Franklin’s Bumblebee (Bombus franklini)
The decline of the Franklin’s bumblebee may be due to the spread of a disease introduced by bumblebees imported from Europe to pollinate commercial crops of tomatoes, peppers and other plants, says Robbin Thorp, an entomologist at the University of California, Davis. Populations of three other closely related bumblebee species are also dwindling, probably for the same reason. Bumblebees are not the only endangered bees in North America. In the past five years, beekeepers have lost up to 90 percent of their honeybee colonies to colony collapse disorder, a mysterious phenomenon whose cause is not yet known; pesticides, pathogens and stress are possible culprits.
But Franklin’s bumblebee could make a comeback. If at least some immune individuals survived the disease, they could repopulate the area, Thorp says. This summer he plans to search for survivors in the bumblebee’s territory. -- EW