Bumble Bee Identification: Colour Bands, Look-Alikes

You identify a bumble bee species by the pattern of yellow, black, orange, red or white hair on its head, thorax and abdomen, read segment by segment. Bumble Bee Watch labels the abdominal segments on the back T1, T2 and so on (T for tergite), and says photos showing the colour pattern on all three body parts are the most useful. Work in this order:

• Confirm it is a bumble bee: fuzzy all over, including the abdomen (Penn State Extension).
• Decide whether it is female: Bumble Bee Watch focuses on females because males vary a lot and are hard to identify from photos. Queens and workers are both female; queens are much larger.
• Read the thorax: is it all yellow, or yellow with a black spot or band?
• Read the abdomen segment by segment: which of T1 to T5 are yellow, black, orange or rusty?
• Compare with your region: the Bumble Bee Watch field guide filters species by head, thorax and abdomen colour and shows range maps and look-alikes.

The American bumble bee (Bombus pensylvanicus) has yellow hair on the front of the thorax, usually a black rear section of the thorax, and yellow on the first three abdominal segments: the back part of T1 plus T2 and T3. Queens are 22 to 26 mm long and workers 13 to 19 mm (Wikipedia). It ranges widely across the eastern United States and Great Plains and into extreme southern Canada (Xerces Society). Wikipedia reports that its numbers dropped nearly 90% in the first two decades of this century and that the IUCN lists it as Vulnerable.

The rusty patched bumble bee is named for a rusty-coloured patch on its abdomen. On 21 March 2017 it became the first bee in the continental United States to receive endangered species protection, and the University of Minnesota Bee Lab says Minnesota is one of the few places where it can still be found. If you think you have photographed one, submit it to Bumble Bee Watch so experts can verify it. See also bee and wasp identification.

• Carpenter bees: the most common mix-up, especially with big bumble bee queens. Carpenter bees have a shinier abdomen with fringes of hair on some segments (UC IPM), while a bumble bee is fuzzy all over (Penn State Extension). Female carpenter bees are about 5/8 to 1 inch long and bore half-inch holes in wood (UC IPM).
• Honey bees: a separate, smaller bee; see bees.
• Bee-mimicking flies: hoverflies that copy bees and wasps have one pair of wings, short stubby antennae and large round eyes (The Wildlife Trusts); a bumble bee, like other bees, has two pairs of wings.
• Hornet moths and other furry moths: a furry body, small eyes and no defined waist (The Wildlife Trusts).

Seeing a bumble bee in summer is not rare: Minnesota alone has 24 species (University of Minnesota Bee Lab). But many species are in trouble. The Xerces Society says more than a quarter (28%) of North American bumble bees face some degree of extinction risk, from habitat loss, disease, pesticides and climate change, and about a third of North American species are declining (University of Minnesota Bee Lab). Particular species, such as the rusty patched and American bumble bees, have become rare in many places.

Bumble bees usually nest underground in cavities such as abandoned rodent holes, occasionally higher up in places like hay bales. A queen starts the nest alone in spring, it grows through summer to as many as several hundred workers in some species, and only new queens survive the winter, overwintering alone underground (Penn State Extension). Penn State describes bumble bees as docile insects that rarely conflict with people, so a nest away from paths can usually be left to finish its season. If someone in the household is allergic to stings, get a professional opinion. See bee and wasp nests.

The University of Minnesota Bee Lab says bumble bees prefer natural nest sites to bee houses, which have a 0 to 10% success rate. Leaving compost piles, dried grass at the base of clumps, logs, sticks and leaf litter gives queens places to nest; planting flowers such as bee balm, anise hyssop and asters and keeping pesticide-free areas also helps. Your photos count too: Bumble Bee Watch and the Bumble Bee Atlas collect sightings from the public (Xerces Society).

Photograph the bee from above and from the side so the thorax and every abdominal segment show, plus the face if you can. Photograph the bee and InsectLens identifies it. For a species record, the University of Minnesota Bee Lab recommends submitting clear photos to Bumble Bee Watch, where experts verify them.

Research and drafting for this page used AI assistance. Every figure, date and quotation was then checked line by line against the sources listed at the bottom of the page, each of which was opened while writing. Nothing here is a diagnosis. If a bite, sting or contact with an insect is followed by trouble breathing, swelling of the face or throat, spreading redness, fever or any symptom that worries you, get medical care; in the United States Poison Help (1-800-222-1222) is free and open 24 hours a day.