Insect · GBIF taxon 1340429
Western Bumble Bee
Bombus occidentalisAlso known as Western Bumblebee
Western bumble bees are vital native pollinators across mountains, meadows, and agricultural fields of western North America. Colony life begins in spring when overwintered queens emerge to construct subterranean nests, while summer workers perform buzz pollination to gather pollen and nectar. Significant population declines over recent decades stem largely from introduced parasites and habitat loss.
PollinatorSocial Insect
1 / 7—observations
—countries
—peak records
VulnerableConservation statusIUCN Red List categoriesLCNTVUENCREWEXVulnerableRed List categories, explained →
Diet & prey
- Flower nectar
- Pollen
Predators
- Robber flies
- Crab spiders
- Bears
ThreatsFungal parasites, habitat degradation, climate change, and pesticide exposure
HabitatsMontane meadows, open fields, mountain forests, and urban gardens
Life span4 to 8 weeks for workers; up to 1 year for queen bees
Size / weightNot available
Classification
- FamilyApidae
- SpeciesBombus occidentalis
Range data is not available yet.
Interaction riskLow
- Low
- Moderate
- High
- Very high
- Why interaction risk is low
- Females sting when defending their nest; observe quietly from a brief distance.
- Why it is dangerous
- Stings contain complex proteins that cause immediate pain, localized swelling, and potential systemic anaphylaxis in sensitive individuals.
- How to recognize a risky encounter
- Look for a stocky, fuzzy bee with yellow bands across the front thorax and a distinct pale white tip on the abdomen.
- What to do
- Maintain a calm distance when observing foraging bees, and avoid stepping near active underground nest burrow entrances.
- What to notice
- Recognizable by its yellow anterior thorax patch, dark middle abdomen, and noticeably white tail segment.
- Support conservation
- Report sightings to community conservation programs and refrain from trapping or catching wild specimens.
Responsible observation
- Planting Native Flora: Cultivate native asters, penstemons, and clovers to provide reliable forage from spring through fall.
- Pesticide Caution: Avoid synthetic insecticides on flowering plants where wild pollinators feed.
- Nest Protection: Leave undisturbed ground cover or old rodent burrows to offer winter shelter for queens.
Co-occurring Species no rights reserved, uploaded by USGS Bee Inventory and Monitoring Lab · cc0
Close Relative (c) psweet, some rights reserved (CC BY-SA), uploaded by psweet · cc-by-sa
Close Relative (c) Bill Keim, some rights reserved (CC BY) · cc-by
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