Wild Bees Are Delightful - Series 5 Article 3 - Bumblebees - (family Apidae, genus Bombus)
By Bonnie McNamee
Bumblebees are native, large furry bees. Bombus is
Latin for “buzzing” or “deep roar”. They are often black and yellow but can
have white, red or orange hairs. Species in this genus have very similar body
shapes, but can be distinguished locally by their color patterns. They are
social bees. The females store collected pollen in specialized corbiculae or
“pollen baskets,” smooth, bowl-shaped structures ringed with long hairs on the
upper part of their hind legs.
Photo by: Dan Mullen, via Flickr
They are among the first bees to emerge in spring and
the last to remain active. They are able to fly in cold, rainy weather and are
excellent pollinators. They have several physiological adaptations that allow
them to fly in bad weather, including the ability to shiver to raise their body
temperature. They are often the dominant bee at high elevations. Bumblebees
make a low buzzing sound when flying.
The large queens are often found foraging on early
blooming species. They visit a
succession of flowers throughout the flowering season. Many bumblebee species
have long tongues that enable them to access nectar from deep flowers such as
foxglove, honeysuckle, columbine, and monkshoods. Bumblebees are often used as
pollinators of greenhouse tomatoes and cranberries, and colonies are
commercially reared just to pollinate these crops. They are also important
pollinators of alfalfa, avocados, apples, cherries, blackberries, blueberries,
eggplants, peppers, melons and strawberries.
According to the Brooklyn Botantic Garden they are the only known
pollinators of potatoes worldwide.
Bumblebee queens are the largest (0.5 to 1 inch long),
workers, which are also female but do not lay eggs, are smaller (0.2 to 0.8
inch long), and males are mid-size (0.3 to 0.9 inch long). Mated queens emerge
from hibernating during the winter. These are the large bodied bumblebee that
you see in early spring. She then finds a new nest, often an old rodent hole or
other premade cavity and lays her eggs.
For the next few weeks, she works much like a solitary bee, foraging for
nectar and pollen and laying eggs. She
does all the work on the colony until those first larvae, her daughters become
adults. Then the queen devotes herself
to egg laying and the daughters take over that work. The final groups of eggs laid at the end of
the summer contain queens for the next year.
Those queens will mate and forage outside of the nest, putting on enough
fat to survive hibernating through the winter.
As winter approaches, these queens will dig hibernacula, sites for
overwintering, often in a sunny bank and will stay there until the following
spring.
Queens fly in late winter or early spring. Workers fly in spring, summer, and fall, and
new queens and males fly in the late summer and fall.
Bumblebees do not see the color red; they are attracted
to blue, purple, orange and yellow.
This is the third in a four part series on bees. Please return next week for Part IV –
What Can Be Done To Help Bees In Decline
