Wed March 14, 2012
Earth Notes: Bumblebees on the Colorado Plateau and Beyond
With bee populations declining worldwide, news is often grim in the world of bee research. But last August, entomologists from the University of California at Riverside found something to cheer about: they spotted three members of a bumblebee species long feared extinct.
Last documented in 1956, the Cockerell’s bumblebee of south-central New Mexico is the country’s rarest bumblebee.
More than 45 bumblebee species live in the United States. As with their cousins, the honeybees, many bumblebee populations have fallen sharply in recent years. Scientists point to many causes, including disease, pesticides, climate change, and competition with non-native bees.
That’s a big concern. Bumblebees are even more efficient pollinators than honeybees. That’s because a worker bumblebee vibrates her wings as she probes a flower, shaking pollen loose. This behavior makes bumblebees indispensable pollinators of commercial crops like tomatoes and blueberries.
Because bumblebees can fly in much colder temperatures than other bees, they are also key pollinators of plants that bloom early, or that live at high elevations. By shivering their wing muscles, bumblebees can raise their body temperature from 43 degrees to 86 degrees in just 15 minutes.
Bumblebee queens are the only colony members to survive the winter. They emerge from underground hibernation in early spring. Each queen sips nectar and gathers pollen, then lays her first eggs, beginning a new bumblebee colony. In coming weeks, watch for these hardy insects here on the Colorado Plateau: they’re a sure sign that spring has arrived.