Bees in general
One important ecological character that sets bees apart from the rest of their wasp relatives is that they use pollen as a protein source to feed their larvae; all other wasps kill arthropods for protein. This pollen-gathering habit is the reason many bees are so fuzzy in appearance—the feathery hairs on their legs or abdomen are used to store and transport pollen. By moving pollen from plant to plant as they forage (also for nectar), bees provide an essential ecological service in both natural and cultivated ecosystems. Humans have long been aware of the importance of bees in pollinating many of their crops (and for providing products such as honey), and have domesticated social bees to perform this work. While the best known bees, honey bees and bumble bees, are social and have communal nests, the vast majority of North American bees are solitary—each female makes her own nest. To date, we have identified over 90 species of bees on the Boston Harbor Islands, including four species of bumble bees. Humans tend to have mixed feelings about bees, they may appreciate their work, but they fear their sting! However, even the irritating venom delivered through the female stinger (a modified egg-laying structure) may benefit humans as a treatment for inflammatory diseases.
How to identify common eastern bumble bees
Bumble bees are larger than most other bees; the queens can reach over 2 cm in length. They are all quite fuzzy (note that carpenter bees, with which bumble bee queens could be confused, have an almost hairless, glossy, dark abdomen). An easily distinguishable feature for most bumble bee species is the pollen-carrying structure. In females, the hind legs each have a flattened, shiny area surrounded by long hairs. These "corbicula" serve as baskets to carry pollen, and you will see bumble bees buzzing about with enormous yellow/orange balls of pollen on their legs. Once you know you're looking at a bumble bee, the common eastern bumble bee is recognizable because it is the only local species that has yellow hairs on ONLY the first abdominal segment (closest to the thorax where wings are attached).
Where to find common eastern bumble bees on the Boston Harbor Islands
This species is likely to be on almost any island if there are plants to pollinate. Because they have a rather "generalist" diet, common eastern bumble bees may be found collecting nectar and pollen on many plant species. You will often find them buzzing in the flowers along trails or in meadows. Bumble bees are also one of the few kinds of insects you will see flying on cool or damp days, as they can "shiver" to warm up their wing muscles for flight.
How common eastern bumble bees make a living
Bumble bees are primitively social insects and usually nest in the ground, often making use of old rodent burrows. Unlike honey bee hives, their nests last for just one season. Fertilized queens hibernate during the winter and emerge in the spring to feed and then lay eggs in a suitable nest. The first bees to develop are sterile female workers. As the season progresses, more and bigger workers are produced, as well as males and new queens. The common eastern bumble bee has relatively large nests compared to other bumble bees, often containing over 400 workers. Males and new queens leave the nest and mate in autumn. Only the mated queens survive the winter, while all the males and workers die off. Common eastern bumble bees have a long active season, from March to November.
Where in the world common eastern bumble bees occur
Bumble bees are common in temperate climates, especially in Eurasia and North America, but they are also found in extremely hot and cold regions, and are native to all continents except Australia. Common eastern bumble bees range from Maine and Ontario down the Atlantic coast to Florida. Although the western edge of their natural range is the mid-west, the bees have been introduced to the western United States for commercial pollination services—a practice that has sparked some controversy.
To learn more about common eastern bumble bees (and bees in general)
On the web:
— identification key to bumble bees and their mimics
— information about the recent decline of bumble bees
Goulson, D. 2003. Bumble bees: their behaviour and ecology. Oxford University Press, Oxford, UK.
Kearns , C.A., and J.D. Thomson. 2001. The natural history of bumblebees: a sourcebook for investigations. University Press of Colorado, Boulder, CO.
O'Toole, C. and A. Raw. 1991. Bees of the world. Blandford Publishing, London, UK.