Bumblebees are very important pollinators of both wild native plants and agricultural crops. Because bumblebees have the ability to fly in cooler temperatures and when it is darker, they will be pollinating flowers earlier and later in the growing season and during the lower light of dawn and dusk. This ability is unique to bumblebees, as they are one of the few insects that are able to generate body heat (thermoregulation) and fly when it's cold, allowing them to live in more northern climates and at higher elevations.
What's for Dinner?
Bumblebees are generalists when it comes to choosing the flowers they pollinate while foraging for nectar and pollen. In general, they have a preference for blue, purple, pink, and yellow flowers and are actually color-blind to red (unless the red flowers have ultraviolet markers they can see).
Bumblebees, more so than other native bees and honeybees, prefer perennial plants as opposed to annuals, as perennials tend to have larger quantities of nectar. (See the list at the end of this article to learn the genera of perennial and woody plants that they prefer.)