Dinosaur National Monument Bumble Bee Guide 🐝

Queen 18 - 23 mm
Worker 10 - 16 mm
Male 12 - 18 mm
Plant Association: Cirsium, Dipsacus, Helianthus, Medicago, Phacelia, Trifolium
Nest: Nests underground or on the surface of the ground
Similar Species:
Rusty-patched Bumble Bee (B. affinis)
Southern Plains Bumble Bee (B. fraternus)
Morrison's Bumble Bee (B. morrisoni)
Red-belted Bumble Bee (B. rufocinctus)
Phenology:
Males: Late July to Early September
Workers: Slow increase from April to Mid-June, Full peak from Mid-June to Late September
Queens: Late March to Late June, Small peaks in August and November less ↑

Queen 18 - 21 mm
Workers 11 - 17 mm
Male 13 - 16 mm
Floral Association: Cirsium, Dipsacus, Helianthus, Penstemon, Phacelia, Trifolium
Nest: Nests often built underground on the ground surface, or above ground in deserted rodent nests
Similar Species:
American Bumble Bee (B. pensylvanicus)
Nevada Bumble Bee (B. nevadensis)
Other regions:
Northern Amber Bumble Bee (B. borealis) Canadian Maritimes and eastern US in Temperate and Boreal Forests regions
Northern Yellow Bumble Bee (B. distinguendus) Alaska
Phenology:
Males: Early July to early October
Workers: Early May to late August
Queens: Early April to mid-June less ↑

Size:
Queen 22 - 26 mm
Worker 12 - 22 mm
Male 15 - 20 mm
Floral Association: Chrysothamnus, Cirsium, Cleome, Helianthus, Lupinus, Melilotus
Nest: Nests underground
Similar Species:
Brown-belted Bumble Bee (B. griseocollis)
Rusty-patched Bumble Bee (B. affinis)
Southern Plains Bumble Bee (B. fraternus)
Phenology:
Males: Slow increase from mid-May to early November
Workers: 2 peaks from mid-April to mid-July and mid-July to late winter season
Queens: Early March to early June less ↑

Queen 24 - 25 mm
Worker 15 - 21 mm
Male 16 - 19 mm
Floral Association: Astragalus, Balsamorhiza, Ceanothus, Cirsium, Helianthus, Melilotus, Ribes, Vicia
Nest: Nest underground, sometimes on the surface
Similar Species:
American Bumble Bee (B. pensylvanicus)
Golden Northern Bumble Bee (B. fervidus)
Black and Gold Bumble Bee (B. auricomus) US Eastern Temperate Forest region
Phenology:
Males: Small peak from Mid-May to Early July, Full peak from Mid-July to Late April
Workers: Slow increase from Mid-April to Mid-June, Full peak from Mid-June to Early September
Queens: Early April to Late June less ↑

Queen 18 - 21 mm
Workers 8 - 17 mm
Male 10 - 15 mm
Floral Association: Cirsium, Clarkia, Ericameria, Eriogonum, Lupinus and Phacelia
Nest: Abandoned rodent dens or other dry hollows in the ground
Similar Species: Fog-belt Bumble Bee (B. caliginosus), Western Bumble Bee (B. occidentalis), Van Dyke's Bumble Bee (B. vandykei)
Phenology:
Males: Late July to Early September
Workers: Mid-April to Early July and August
Queens: Late March to Early May less ↑

Queen 22 - 26 mm
Worker 13 - 19 mm
Male 15 - 21 mm
Floral Association: Chrysothamnus, Gossypium, Helianthus, Kallstroemia, Linaria, and Viguiera
Nest: Nests mostly on the surface of the ground, occasionally underground
Similar Species:
Golden Northern Bumble Bee (B. fervidus)
White-shouldered Bumble Bee (B. appositus)
Nevada Bumble Bee (B. nevadensis)
Other regions:
Northern Amber Bumble Bee (B. borealis) Canadian Maritimes and eastern US in Temperate and Boreal Forest regions
Black and Gold Bumble Bee (B. auricomus) Eastern Temperate Forest region
Northern Yellow Bumble Bee (B. distinguendus) Alaska + Europe and Asia
Phenology:
Males: Mid-August to Late October
Workers: Late August to Mid-October
Queens: Late May to Early July, with a small peak in September and October less ↑

Size: Medium
Queen 20-21 mm
Workers 9 - 15 mm
Male 12 - 16 mm
Floral Association: Melilotus, Cirsium, Trifolium, Centaurea, Chrysothamnus and Eriogonum
Nest: Nests usually underground
Similar Species:
Yellow-banded Bumble Bee (B. terricola)
Franklin Bumble Bee (b. franklini)
Cryptic Bumble Bee (B. cryptarum)
Phenology:
Males: July to September
Workers: June to September
Queens: March to August less ↑

Size:
Queen 15 - 17 mm
Workers 10 - 14 mm
Male 11 - 14 mm
Floral Association: Epilobium, Lupinus, Rubus, Senecio, Symphoricarpos, and Trifolium
Nest: Nests are built below ground, on the ground surface and above ground
Similar Species:
Black-tailed Bumble Bee (B. melanopygus)
High Country Bumble Bee (B. balteatus)
Phenology:
Males: May to July
Workers: Early March to Late July
Queens: Mid-February to Early May less ↑