Buzz pollination

Scientific American reports on why bees buzz: the buzz is created by wing beats and also by buzz pollination techniques:

... some bees, most commonly bumblebees (genus Bombus), are capable of vibrating their wing muscles and thorax (the middle segment of their body) while visiting flowers. These vibrations shake the pollen off the flower's anthers and onto the bee's body. Some of that pollen then gets deposited on the next flower the bee visits, resulting in pollination. The bee grooms the remainder of the pollen onto special pollen-carrying structures (on the hind legs of most bees) and takes it back to the nest to feed to the larvae.

Honeybees are incapable of buzz-pollination.

Some plants such as tomatoes, green peppers and blueberries are adapted to buzz pollination by having tubular anthers with the pollen inside the tube. Vibration causes the pollen to fall out of the anther tube.