Variable Cuckoo Bumble Bee
Bombus variabilis
This record describes Bombus variabilis (species). Recorded family: Apidae. Recorded order: Hymenoptera.
Identification and Appearance
Similar to Bombus insularis but with more extensive black hairs. Males of the southwestern population, e.g, those from southern Arizona, can be difficult to separate. Although Bombus pensylvanicus persists in relatively good numbers in its core range, its social parasite B. variabilis has evidently declined severely and there are few recent records. Texas Parks & Wildlife considers this to be a Species of Greatest Conservation Need (SGCN) **Listed as Critically Endangered by the IUCN Red List of Threatened Species **
Classification
- Kingdom
- Animalia
- Phylum
- Arthropoda
- Class
- Insecta
- Order
- Hymenoptera (Ants, Bees, Wasps and Sawflies)
- Superfamily
- Trigonaloidea
- Family
- Apidae (Cuckoo, Carpenter, Digger, Bumble, and Honey Bees)
- Subfamily
- Apinae
- Tribe
- Bombini
- Genus
- Bombus (Bumble Bees)
Imported taxonomy record. Source availability varies; see the source references and editorial policy below.
Habitat and Range
Geographic Range
e NA (TX-FL-NH-ND) / QC / Mex. to Honduras - Map - Discover Life
Seasonal Activity
June to November, with earlier records in Florida
Diet and Behavior
Diet: A social parasite of Bombus pensylvanicus sensu lato (eastern populations of Bombus variabilis sensu lato parasitize Bombus pensylvanicus whereas southwestern populations parasitize Bombus sonorus ). Both sexes regularly visit flowers for nectar. The Hosts section of its Discover Life species page lists known floral associations based on specimen records.
Additional species information
Species notes from the sources
Etymology: Bombus variabilis (Cresson, 1872)
About Flies: the wider group
Order-level background for Hymenoptera, the group containing Bombus variabilis. Species-specific details appear above.
Group overview
Hymenoptera includes over 150,000 described species of ants, bees, wasps, and sawflies. Earth harbors approximately 20 quadrillion (20×10^15) ants, with a combined biomass of ~12 megatons of dry carbon - exceeding the combined biomass of all wild birds and mammals (PNAS, 2022).
Ecological role of the group
About 35% of the world's food crops depend on animal pollinators. The chocolate industry, valued at over $100 billion, depends on pollinating flies and midges. Ants are the dominant soil engineers in most terrestrial ecosystems, turning more soil than earthworms in many habitats.
Economic and practical significance of the group
Pollinators contribute $235-577 billion worth of annual global food production (FAO). In the U.S., bee pollination alone benefits crops valued at $18 billion annually, and honey bees are responsible for $5.4 billion in agricultural productivity. Between April 2023-2024, 55.1% of managed honey bee colonies were lost. The U.S. bee population dropped from 5 million to 2.5 million.
Recorded sources for this group: FAO, USDA, EPA, PNAS (2022), US Fish & Wildlife Service. Imported estimates may describe particular regions or reporting periods.
Photos of Variable Cuckoo Bumble Bee (4)
Photo credits: Contributed by John S. Ascher; Additional contributions by Beatriz Moisset , Mike Quinn , hg , Nathaniel Green
Frequently Asked Questions About Variable Cuckoo Bumble Bee
What is Variable Cuckoo Bumble Bee?
Variable Cuckoo Bumble Bee (Bombus variabilis) is a species in the family Apidae, within the order Hymenoptera.
How big is Variable Cuckoo Bumble Bee?
| Feature | Details |
|---|---|
| Female | 17.5-19 mm. |
| Male | 14.5-17 mm |
How do you identify Variable Cuckoo Bumble Bee?
Similar to Bombus insularis but with more extensive black hairs. Males of the southwestern population, e.g, those from southern Arizona, can be difficult to separate.
Where is Variable Cuckoo Bumble Bee found?
Range: e NA (TX-FL-NH-ND) / QC / Mex. to Honduras - Map - Discover Life
What does Variable Cuckoo Bumble Bee eat?
The diet of the Variable Cuckoo Bumble Bee includes A social parasite of Bombus pensylvanicus sensu lato (eastern populations of Bombus variabilis sensu lato parasitize Bombus pensylvanicus whereas southwestern populations parasitize Bombus sonorus ). Both sexes regularly visit flowers for nectar. The Hosts section of its Discover Life species page lists known floral associations based on specimen records..
When is Variable Cuckoo Bumble Bee active?
Variable Cuckoo Bumble Bee: seasonal activity - June to November, with earlier records in Florida.