Native pollinators: bumble bees
When I think of cartoon insects, I think of bumble bees. They invariably have bold black and yellow stripes, wide bodies, and a big smile on their faces. You can even buy costumes for your pets, your kids, or yourself that loosely resemble a bumble bee . . . although I’m not sure why.
In truth bumble bees rarely smile, they are more hairy than fat, and they come in a variety of colors. Some are all black, while others have stripes that are lemon yellow, orange, dark rust, red, or white. Stripes may be wide or narrow and vary in number. Bumble bees are easy to recognize because they seldom wear costumes resembling dogs, cats, or kids.
Bumble bees belong to the genus Bombus. They are in the same order (Hymenoptera) and same family (Apidae) as honey bees and, indeed, they have a lot in common. The known bumble bees are divided into 250 species, most of which are found in temperate regions of the northern hemisphere. About 50 species live in North America.
Like honey bees, bumble bees are eusocial, meaning they live in colonies with a reproductive queen and cadre of sterile female workers. The nest of bumble bees is usually found underground and consists of perhaps fifty workers.
At the onset of winter both the female workers and the male drones die. The mated queens overwinter by finding a protected spot and holing up for the duration. Then, in early spring, those queens find a suitable nest, provision it with pollen and nectar, and begin a new colony. The solitary queen does all the work by herself until she has enough female offspring to take over raising the young. Once that happens, the queen stays in the nest and continues to lay eggs.
Within the confines of their nest—often a recycled rodent burrow—the bees build wax comb in which to store food and raise brood. The wax nest is irregular in shape and is often tucked into a soft, warm berth of straw or animal fur.
Bumble bees collect nectar and pollen for the young, carrying home large pellets of pollen on their rear legs. Bumble bees visit many flower types and are efficient pollinators, often pollinating flowers that other bees can’t manage. A famous example is the tomato, which needs the powerful vibration of a bumble bee’s wings to free the pollen from the flower.
Although there are many species of bumble bee, most of the species do not have a wide distribution. As a result, habitat destruction, urbanization, and intensive agriculture have put many species in danger of extinction. Pesticide-free agriculture, urban plantings, hedgerows, and habitat strips can give a boost to declining bumble bee populations.
For the most part, bumble bees are docile as they forage from flower to flower, but they can become aggressive and territorial if their nests are disturbed. Enjoy them from a distance and leave their nests alone if at all possible.