Suckley Cuckoo Bumble Bee - Bombus suckleyi
For definitions and diagrams of bumble bee morphology please see the Montana State Entomology Collection's Bumble Bee Morphology page
. Medium sized and short-tongued: queens 18-23 mm (no workers). Outer surface of hind-leg tibia convex and densely hairy, lacks a pollen basket. Hair short and even, black on the face, predominantly yellow on sides of the thorax, black continuously along midline to anterior region of T4. Males 13-16 mm, hair color on sides of thorax yellow, T2 extensively yellow, T4 mostly yellow sometimes with narrow area of black hairs along midline, T7 black, antenna medium length, flagellum 3x longer than the scape (Williams et al. 2014).
Queens reported April through August, males June through October (Koch et al. 2012, Williams et al 2014). In California, queens reported late May to late October, males early July to late September (Thorp et al. 1983).
Please see the Montana State Entomology Collection's Key to Female Bumble Bees in Montana
. Outer surface of the hind tibia convex, densely hairy and lacking a pollen basket separates B. suckleyi
from other Bombus
except other cuckoo bumble bees. Predominantly black occiput separates B. suckleyi
from other western cuckoo bumble bees, which have predominantly yellow hairs covering the occiput (Koch et al. 2012).
Resident Year Round
Recorded Montana Distribution
Click the map for additional distribution information.
Formerly from the Pacific Coast to the Atlantic Coast across southern Canada and the adjacent northern US. Also in the western US through the Cascades to northern California, and throughout the Rocky Mountain states to northern New Mexico. Now, the occupied range appears much more fragmented, especially across most of southern Canada and throughout the Cascades (Williams et al. 2014). In Colorado, between 2500-3000 m elevation (Macior 1974).
Reported in grassland and shrub-steppe along the Snake River Plain of southeastern Washington, and in conifer forest uplands nearby (Mayer et al. 2000). In the Lower Fraser Valley of British Columbia, they were not detected in commercial berry (Vaccinium, Rhubus) fields, instead preferring native vegetation, and found in greater numbers as distance from commercial operations increased (MacKenzie and Winston 1984). Present in montane to subalpine mesic and wet meadows in Colorado (Macior 1974).
Do not intentionally gather pollen but may transport it (Beattie et al. 1973). Instead B. suckleyi parasitize nests of other bumble bees. Food plants include "asters", Agastache, Centaurea, Chrysothamnus, Cirsium, Epilobium, Erysimum, Frasera, Haplopappus, Iris, Melilotus, Penstemon, Salix, Senecio, Sisyrinchium, Solidago, Symphyotrichum, Taraxacum, Trifolium and Triteleia (Beattie et al. 1973, Macior 1974, Thorp et al. 1983, Mayer et al. 2000, Koch et al. 2012, Miller-Struttmann and Galen 2014).
A social parasite, killing the host and nesting in colonies of other bumble bees, especially B. occidentalis, but recorded from colonies of B. terricola, B. rufocinctus, B. fervidus, B. nevadensis, and B. appositus (Hobbs 1965a and b, Hobbs 1966a and b, Williams 2014). In one southern Alberta study, reported to have depredated 80% of 15 B. occidentalis nests (Hobbs 1968). Males patrol circuits in search of queens (Williams et al. 2014). Apparent declines in B. suckleyi may be tied to declines in their primary host species (B. occidentalis).
Suckley Cuckoo Bumble Bee has been listed on the IUCN Redlist as Critically Endangered due to a decreasing population trend and habitat based threats (Hatfield et al. 2015). In April 2020, the species was petitioned for listing under the Endangered Species Act.
- Literature Cited AboveLegend: View Online Publication
- Beattie, A.J., D.E. Breedlove, and P.R. Ehrlich. 1973. The ecology of the pollinators and predators of Frasera speciosa. Ecology 54: 81-91.
- Hobbs, G.A. 1965a. Ecology of species of Bombus Latr. (Hymenoptera: Apidae) in southern Alberta. II. Subgenus Bombus Robt. Canadian Entomologist 97(2): 120-128.
- Hobbs, G.A. 1965b. Ecology of species of Bombus Latr. (Hymenoptera: Apidae) in southern Alberta. III. Subgenus Cullumanobombus Vogt. Canadian Entomologist 97(12): 1293-1302.
- Hobbs, G.A. 1966a. Ecology of species of Bombus Latr. (Hymenoptera: Apidae) in southern Alberta. IV. Subgenus Fervidobombus Skorikov. Canadian Entomologist 98: 33-39.
- Hobbs, G.A. 1966b. Ecology of species of Bombus Latr. (Hymenoptera: Apidae) in southern Alberta. V. Subgenus Subterraneobombus Vogt. Canadian Entomologist 98: 288-294.
- Hobbs, G.A. 1968. Ecology of species of Bombus (Hymenoptera: Apidae) in southern Alberta. VII. Subgenus Bombus. Canadian Entomologist 100(2): 156-164.
- Koch, J., J. Strange, and P. Williams. 2012. Bumble bees of the western United States. Washington, DC: USDA Forest Service, Pollinator Partnership. 143 p.
- Macior, L.M. 1974. Pollination ecology of the Front Range of the Colorado Rocky Mountains. Melanderia 15: 1-59.
- MacKenzie, K.E. and M.L. Winston. 1984. Diversity and abundance of native bee pollinators on berry crops and natural vegetation in the Lower Fraser Valley, British Columbia. Canadian Entomologist 116:965-974.
- Mayer, D.F., E.R. Miliczky, B.F. Finnigan, and C.A. Johnson. 2000. The bee fauna (Hymenoptera: Apoidea) of southeastern Washington. Journal of the Entomological Society of British Columbia 97: 25-31.
- Miller-Struttmann, N.E. and C. Galen. 2014. High-altitude multi-taskers: bumble bee food plant use broadens along an altitudinal productivity gradient. Oecologia 176:1033-1045.
- Thorp, R.W., D.S. Horning, and L.L. Dunning. 1983. Bumble bees and cuckoo bumble bees of California (Hymenoptera: Apidae). Bulletin of the California Insect Survey 23:1-79.
- Williams, P., R. Thorp, L. Richardson, and S. Colla. 2014. Bumble Bees of North America. Princeton, NJ. Princeton University Press.
- Additional ReferencesLegend: View Online Publication
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- Dolan, A.C. 2016. Insects associated with Montana's huckleberry (Ericaceae: Vaccinium globulare) plants and the bumble bees (Hymenoptera: Apidae) of Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 160 p.
- Dolan, A.C., C.M. Delphia, K.M. O'Neill, and M.A. Ivie. 2017. Bumble Bees (Hymenoptera: Apidae) of Montana. Annals of the Entomological Society of America. 110(2): 129-144.
- Fultz, J.E. 2005. Effects of shelterwood management on flower-visiting insects and their floral resources. M.Sc. Thesis. Bozeman, MT: Montana State University. 163 p.
- Hatfield, R., S. Jepsen, R. Thorp, L. Richardson, and S. Colla. 2015. Bombus suckleyi. The IUCN Red List of Threatened Species 2015: e.T44937699A46440241. https://dx.doi.org/10.2305/IUCN.UK.2015-2.RLTS.T44937699A46440241.en. Acccessed 30 April 2020.
- Kearns, C.A. and J.D. Thomson. 2001. The Natural History of Bumble Bees. Boulder, CO. University Press of Colorado.
- Reese, E.G., L.A. Burkle, C.M. Delphia, and T. Griswold. 2018. A list of bees from three locations in the Northern Rockies Ecoregion (NRE) of western Montana. Biodiversity Data Journal 6: e27161.
- Simanonok, M. 2018. Plant-pollinator network assembly after wildfire. Ph.D. Dissertation. Bozeman, MT: Montana State University. 123 p.
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