A FIELD GUIDE TO BUMBLE BEES OF THE EASTERN UNITED STATES
BOMBUS of the
EAST
“Bees are not optional.” —Sam Droege, biologist for the U.S. Geological Survey
BOMBUS of the
EAST
KEY RANGE, HABITAT, AND ECOLOGY Where to Find
What They Eat
When to Look
Where They Nest
THREAT CATEGORY
CR
EN
VU
Critically Endangered Vulnerable Endangered
NT Near Threatened
LC Least Concern
INTRO THERE ARE OVER 4,000 BEE SPECIES in the entire United States, and forty‑seven belong to the genus Bombus—bumble bees. This illustrated field guide is an engaging resource for the novice melittologist (a scientist who studies bees), providing important information to help identify and explore species commonly found in the Eastern United States. With this identification tool, users can learn to track bumble bee populations and find out why we are losing these extremely essential pollinators. Support bumble bee conservation by uploading photos and reporting findings to the citizen science project, Bumble Bee Watch at www.bumblebeewatch.org.
CR
Bombus affinis
RUSTY PATCHED BUMBLE BEE Rare and endangered, the Bombus affinis (rusty patched bumble bee) is recognizable by its yellow thorax, with a black spot or band between the wing bases and a black tail. The queen’s hair is short and even and the worker’s hair is a medium length. B. affinis is a short‑tongued species, typically found on open flowers close to or within woodlands. It has also been documented in grasslands, marshes, and more recently residential parks and gardens.
CT, MA, MD, VA
July to October
BEE INFORMED Bumble bees make a small amount of honey to feed the colony for a few days during bad weather.
Underground Helianthus (sunflowers) Lonicera (soneysuckles) Solidago (goldenrods)
LC
Bombus bimaculatus
TWO‑SPOTTED BUMBLE BEE Commonly found is the Bombus bimaculatus (two‑spotted bumble bee). It is recognizable by its yellow thorax, a black spot between the wing bases, a yellow w–shape in the middle, and a black tail. Both the queen and the worker bees have long uneven hair. B. bimaculatus is a medium‑length tongued species. It is typically found nesting underground in agricultural and urban (parks and gardens) areas. It is often associated with wooded habitats.
DC, MD, NY, VA
April to October
BEE INFORMED Bumble bees shake pollen loose from plants then carry the pollen in baskets on their hind legs.
Ground surface and underground Cirsium (thistles) Hypericum (St. John’s wort) Melilotus (sweet clovers)
EN
Bombus fraternus
SOUTHERN PLAINS BUMBLE BEE The Bombus fraternus (Southern Plains bumble bee) is endangered due to changes in its habitat. If spotted, this rare, short‑tongued bumble bee is easily identifiable by its black tail—extensively yellow thorax—and a short black band between the wing bases. It has very short even hair and unique dark wings. B. fraternus is associated with grasslands and urban gardens. The males are known to chase moving objects when searching for mates.
MA, NJ, VA
April to September
BEE INFORMED Bumble bees choose food‑plants that have depths similar to the length of their tongue.
Underground Hypericum (St. John’s Wort) Monarda (bee balms) Solanum (nightshades)
LC
Bombus griseocollis
BROWN‑BELTED BUMBLE BEE Bombus griseocollis (brown-belted bumble bee) is a common bumble bee. This generalist species is detectable by its primarily yellow thorax with a black spot between its wings bases, a yellow or brown crescent shape, a black tail, a medium‑length tongue, and short hair. It reportedly can be found early in the season in New York City’s community gardens. B. grisoecollis visits a variety of areas including farmlands, fields, meadows, and urban parks and gardens.
DC, MD, NY, VA
June to September
BEE INFORMED Bumble bees generate heat by shivering. They must reach a minimum of 30° C for flight.
Ground surface Asclepias (milkweeds) Helianthus (sunflowers) Lythrum (loosestrifes)
LC
Bombus impatiens
COMMON EASTERN BUMBLE BEE The common Bombus impatiens (common eastern bumble bee) species is recognizable by its pale yellow thorax with black hairs intermixed between the wing bases and an entirely black lower abdomen and tail. Using its medium‑length sized tongue, B. impatiens visits over one hundred native plant genera throughout its range. It adapts well in a variety of habitats, nectar sources, and climates. It does well in agricultural, wetland, and urban areas.
DC, MD, ME, NY
May to October
BEE INFORMED Bumble bees engage in buzz polllination—a foraging technique in which they shake pollen from flowers.
Underground Cirsium (thistles) Pontederia (pickerel weeds) Solidago (goldenrods)
LC
Bombus perplexus
CONFUSING BUMBLE BEE Ranked as a less vulnerable and more common bumble bee, Bombus perplexus (confusing bumble bee) is distinguishable by its pale brown or yellow thorax, black sides beneath its wings, and a black tail with white hairs. Its hair is unusally long and wiry and its tongue is medium‑length. A generalist species, B. perplexus visits a variety of flowering plants within wooded areas, urban parks, gardens, and wetlands. Males patrol circuits for mates while nesting.
DC, MD, VA, WV
May to September
BEE INFORMED Queen and worker bumble bees can sting when threatened. Drones (males) do not have stingers.
Ground surface, logs, and trees Campanula (bellsflowers) Lonceria (honeysuckles) Penstemon (beardtongues)
VU
Bombus terricola
YELLOW-BANDED BUMBLE BEE Declining at an alarming rate, the Bombus terricola (yellow‑banded bumble bee) species is identifiable by its dominant yellow‑band thorax, its black and yellow abdomen, and its black or yellow tail. It also has a round face and short hair. This vulnerable species inhabits a wide variety of habitats such as woodlands, farmlands, urban areas, meadows, grasslands, and wetlands. B. terricola is commonly found robbing nectar of flowers with long‑corollas (petals).
MD, PA, NJ, VA
April to September
BEE INFORMED Bumble bees are able to forage under cold conditions; they stay warm by vibrating their flight muscles.
Underground Lonicera (honeysuckles) Salix (willows) Solidago (goldenrods)
LC
Bombus vagans
HALF‑BLACK BUMBLE BEE Bombus vagans (half-black bumble bee) has been less susceptible to threat. This common species is discoverable by its yellow thorax with a black spot between its wing bases, yellow sides, and a black tail. B. vagans is also distinguishable by its long face and short body with lengthy hair. This species forages on a large number of flowers nearby or in wooded areas, urban parks, wetlands, and gardens. Unlike most bumble bees, it forages in heavily shaded areas.
DE, MA, MD, PA
April to October
BEE INFORMED Bumble bees have four wings—two front and two rear—that flap over two hundred times per second.
Ground surface and underground Asclepias (milkweeds) Penstemon (beardtongues) Spirea (meadowsweet)
IMAGES CREDITS ON THE COVER FRONT Droege, Sam. Bombus perplexus Face. 2019. USGS Bee Inventory and Monitoring Lab. Accessed via Flickr. BACK Droege, Sam. Bombus perplexus Section. 2019. USGS Bee Inventory and Monitoring Lab. Accessed via Flickr.
INSIDE THE COVER WING IMAGES Weidne, Ralph. 2019. Accessed via Flickr. BUMBLE BEE IMAGES Droege, Sam. 2019. USGS Bee Inventory and Monitoring Lab. Accessed via Flickr.
BIBLIOGRAPHY Droege, Sam. “Bees Are Not Optional: To Know How Bees Fare, You Must Know Who They Are.” Interviewed by Catherine Puckett, Natural Science Collections Alliance, May 2011. https://www.actionbioscience.org/management_and_ conservation/puckett. “Bumble Bee Conservation.” Xerces website, https://xerces.org/bumblebees (accessed March 2019). Colla, Sheila, Richardson, Leif, Williams, Paul. “Bumble Bees of the Eastern United States.” US Forest Service website, https://www.fs.fed.us/wildflowers/ pollinators (accessed March 2019). The IUCN Red List of Threatened Species website, https://www.iucnredlist.org (accessed March 2019).
Bombus of the East: A Field Guide to Bumbles Bees of the Eastern United States is researched, written, and designed by Yvonne Eder for Information Design, a course in the Integrated Design master of arts program at the University of Baltimore, spring 2019.