Brown-belted bumble bee (Bombus griseocollis) is a common bumble bee in the northeast, often found in gardens, parks, and cities. Most males and female can be easily identified from the short “buzz cut” hairs on thorax, lemon-yellow T1 and brown-yellow band on T2. Small nests are active throughout the early part of the year—from March through August. This is often the predominate bumble bee on common milkweed (Asclepias syriaca).
Active April through September. Colonies begin producing males and gynes (future queens) by late July and August; one new generation of reproductive individuals per year.
Widespread throughout region. This bee has an enormous range: from Atlantic coast to California in low elevations, but is absent from the desert southwest.
Size > honey bee
Workers: thorax with short “buzzcut” hair and black spot in center, T1 completely yellow; T2 with yellow or brown crescent band, not completely covering width of T2
Gynes: like workers but T2 often with yellow; 2-3x as big as workers
Males: many with similar pattern to females, but with bulging “fly-like” eyes, longer antennae, more rounded abdomen, and thick yellow “moustache” on face
- Two-spotted bumble bee (Bombus bimaculatus) has a small yellow spot flanked by black on T2
- Eastern carpenter bee (Xylocopa virginica) are similar sized to queens, but carry pollen in brush-like scopae on hind legs, not corbiculae; have darker, mustardy thorax pile, and wide, squat face; and black shining abdomen (vs. matte/luster abdomen of B. griseocollis)
Associated with open lands. Mated gynes (future queens) emerge early in spring and found small colonies in cavities, typically at ground-level. Known to nest alongside humans in a variety of cavities, including old rodent burrows or beneath thatch or grass tussocks in parks, backyards, cities, meadows, and prairies.
Highly generalized. Short-tongued species often found on Fabaceae like false indigo (Baptisia spp.), lupine (Lupinus spp.), eastern redbud (Cercis canadensis) and sweet clovers (Melilotus spp.). Also often found common milkweed (Asclepias syriaca), coneflower (Echinacea spp.), and thistles (Cirsium spp.).
We are unaware of any cuckoo bees that parasitize B. griseocollis.
Page last updated:
February 22, 2023