Yellow-faced bumblebee

[ BOMBUS VOSNESENSKII ]

On warm spring days big hairy bees meander in heavy flight. Though bulky and apparently clumsy, bumblebees have a rather swift survival strategy. Unlike smaller bees, which wait to come out until late in the season, bumblebees take advantage of early blooming wildflowers. Many of these flowers have evolved anthers that release pollen to only the larger bees. Upon landing, bumblebees vibrate their wings at a special, clearly audible frequency that shakes pollen free -- a process called “buzz pollination.” In exchange, the bees receive meals of rich nectar unavailable to insects trying to steal a snack without triggering a pollen release.

NATURAL HISTORY

The first bumblebees to emerge each spring are queens that have survived the winter. Between visits to flowers, they dip down to the soil, looking for places to dig a burrow and start a new colony. In late summer, the colony raises reproductive adults that quickly mate as the other bees die. These large, gentle insects play an extremely important role in ecosystems.

KEY CHARACTERISTICS

Black, inch-long bees with lemon-yellow faces and a yellow band encircling the tips of their abdomen are found at lower elevations throughout California.