Bumble bees are fuzzy, efficient, colorful pollinators. Arizona's mountains are home to a dozen species of bumble bees, out of nearly 50 that are native to North America, and 250 worldwide. In Northern Arizona, the most common bumbler is the beautiful orange, yellow and black Hunt’s bumble bee.
Southwestern bumble bees are found in mountainous regions because bumble bees originated on the high Himalayan plateau and spread from there. Only one species, the Sonoran bumblebee, can survive in the desert. Bumble bees make honey, but much less than nonnative honeybees because unlike them, bumble bee colonies die in fall. Beneath the winter snow, only the summer’s new queens survive, sometimes hibernating in an unoccupied mouse burrow.
In spring, the queens emerge, feed on flowers and find a site for their nest. They mix a ball of pollen and nectar, then lay a few eggs on it. Queens warm the eggs by sitting on them like a hen while vibrating their wing muscles without flapping, fueled by nectar sipped from a nearby wax cup. The eggs hatch into grub-like larvae which eat the pollen and nectar ball, pupate, then emerge as workers. While honeybee hives may contain 30,000 bees, bumble bee colonies range from about 30 to 400.
Near the end of summer, new queens and male drones emerge. The old, exhausted queens and workers die. After mating, the new queens crawl into burrows and hibernate, while the drones drink nectar and sleep in the flowers until their short lives end.
This Earth Note was written by Elizabeth Blaker and produced by KNAU and the Sustainable Communities Program at Northern Arizona University.
