MAKE HONEY, TOO
Q. We would like to get some information about bumblebees, these creatures that appear in our backyard as a buzzing cloud of yellow and black. We sit each summer day among hundreds of them that blatantly pilfer the pollen from our many flowers, and it just recently dawned on us that we know birds, hummingbirds, bees, and quite a bit about butterflies, but our knowledge concerning the bumblebee is woefully lacking. Will you help us, please?
The general question was followed by a list of several specific questions such as "Where do they nest? Is it a hive? Do they make honey? What is the purpose of their pollen gathering? Does the normal bumblebee mate, or is that privilege for the hierarchy? Do they sting? Do they have a natural enemy?"
A. Bumblebees, with their rounded, robust bodies, remind me of linebackers that play for a team whose school colors are black and yellow. They are highly watchable creatures to have around a yard. Most bumblebees, of which there are more than 200 species worldwide and 50 in North America, are social insects that live in a nest they build, often in an abandoned mouse nest. I have a bumblebee nest in my yard that is in a bird box that had been the home of flying squirrels this past winter and spring. Like their close relatives the honeybees, bumblebee colonies have a queen. The queen is recognizably larger than the worker bees, all of which are female. Queen bumblebees apparently will sometimes leave the nest to forage like the worker bees. Male bumblebees are known as drones, and their sole purpose is for mating.
Like some of the other social bees and wasps, bumblebees will sting, but only if threatened or provoked, such as when the nest is disturbed. Drones have no stingers and they do not gather pollen like the workers. Most bumblebees are extremely benign, especially when compared to yellow jackets or hornets, which seem to protect their nests with a vengeance. I have never heard of a bumblebee stinging anyone who simply stood and watched one gather pollen on flowers, although they might sting anyone that disturbs a nest and stays to have a closer look.
Honeybees and bumblebees are attracted to flowers to get the sweet-smelling
nectar and pollen. During the nectar-gathering process, insects such
as bees also transfer pollen from one flower to another, serving an
essential role in pollination, a requirement for some plants to successfully
produce fruits and seeds. Nectar is returned to the nest by the bee,
allowed to dry to a certain level, and then in a complex process that
involves bee saliva and special enzymes, is eventually converted to
honey. Honey is used to feed members of the colony. Bumblebees produce
honey but never in the quantities found in honeybee hives. Bears probably
spend little time looking for bumblebee nests to raid.
As far as natural enemies, adult bumblebees probably have few because most predators would prefer not to risk being stung for such a small meal. Ironically, one of the greatest threats to bumblebee colonies in some areas is another kind of bumblebee that is not social. These are nest parasites, sometimes even killing the queen of the colony, laying eggs, and having their own developing young fed by the bumblebees of the colony.
I enjoyed the bumblebee questions. I like to see people become aware
that we are surrounded by ecological mysteries and intrigue in the everyday
wildlife around us.