The giants among us.
Bumble bees are a charismatic group considered by some to be the “pandas of the bee world”. Bumble bees belong to the genus Bombus, with around 260 different described species. Besides their importance as excellent pollinators, these bees are declining worldwide due to different factors: habitat fragmentation, pesticides, diseases, climate change, etc (Williams and Osborne 2009, Cameron et al 2011).
Here in the USA the rusty patched bumble bee Bombus affinis has declined in about 90% of its historic distribution (north and the north-eastern USA) in only 20 years (Jepsen et al 2013). This drastic population decline resulted in the rusty patched bumble bee becoming one of the first species of continental bee to be included in the Endangered Species Act (Thorp et al).
In Oklahoma, there were historically 10 species of bumble bees: the American bumble bee, B. pensylvanicus, the brown belted bumble bee B. griseocollis, the southern plains bumble bee B. fraternus, the common eastern bumble bee B. impatiens, the black and gold bumble bee B. auricomus, the two-spotted bumble bee B. bimaculatus, the indiscriminate cuckoo bumble bee B. insularis, the white shouldered bumble bee B. appositus, the Morrison bumble bee B. morrisoni and the variable cuckoo bumble bee B. variabilis. But our species are declining too. In 2015, University of Oklahoma Laura Figueroa and Elizabeth Bergey surveyed the state for bumble bees and only found 4 species: B. pensylvanicus, B. griseocollis, B. fraternus and B. impatiens (Figueroa & Bergey 2015). Attempts by the researchers to track down even recently known populations, such B. auricomus in canola fields reported by Baum and McCoshum in the 2000–2013 period (mentioned in Figueroa and Bergey 2015) were unsuccessful.
Bumble bees at the OKC Zoo and Botanical Garden
The over 100 acres of green space at the OKC Zoo and Botanical Garden including some of the specialized gardens such as the butterfly garden and the new wetland walkway offer a great habitat for bees. These gardens really are a sanctuary for pollinators in Oklahoma.
Bumble bees are annual species, unlike honey bees, which form perennial colonies with long-lived queens. Every spring, new bumble bee queens need to start their colony from scratch. At the OKC Zoo, you can see this phenomenon in the month of April, when hundreds of young queens emerge from their hibernation and forage on many of the flowers at the park.
In the present survey, we have found 6 species of bumble bees: the four species mentioned in the work of Figueroa and Bergey (2015) and two species formerly considered extirpated: B. auricomus and B. bimaculatus.
American bumble bee
Bombus pensylvanicus (De Geer, 1773)
This bumble bee is common throughout our state. Once the most prevalent bumblebee in the southern United States, as its name suggests, populations of this species have decreased significantly in recent years, especially in their northern distribution (MacPhail et al 2019, Richarson et al 2018, Rowe et al 2019 ). As of today, the American bumble bee is listed in the “vulnerable” category (Hatfield et al 2015).
In the park, this bee visits a great variety of flowers (Liatris, Cone flowers, Chaste tree, Wisteria, Redbuds, Sunflowers, Trumpet vine, etc). Easy to spot at the Butterfly Garden, Sanctuary Asia, the Pick Family Garden, and the Devon Picnic Area.
Brown-belted bumble bee
Bombus griseocollis (De Geer, 1773)
This is another common bumble bee of Oklahoma and maybe the most common species of bumble bee at the park. This is a common species in much of its wide range in the US. Unlike many bumble bees in North America, It apparently faces no serious threats. Its distinctive character is the belt of brown hairs on the second segment of their abdomen. This species flies everywhere visiting a wide spectrum of flowers (Liatris, Coneflowers, Chaste tree, Wisteria, Redbuds, buttonbush tree, Milkweed, etc), but you can find them more frequently at Sanctuary Asia and the Devon Picnic Area.
Common eastern bumble bee
Bombus impatiens Cresson, 1863
The common eastern bumble bee is not so common in Oklahoma. As a species strongly associated with the eastern temperate forest, its distribution is more restricted to the eastern border of the state. However, we found this bumble bee flying around the OKC Zoo. Specifically, it was found in Sanctuary Asia and at the Pick Family Garden.
Southern plains bumble bee
Bombus fraternus (Smith, 1854)
This bumble bee species used to be common in the southern plains, but in recent years has become very rare. The drastic decline in their populations has caused the species to be listed as “endangered” on the IUCN Red List (Hatfield et al 2014). We found this bumble bee at the Butterfly Garden.
Black and gold Bumble bee
Bombus auricomus (Robertson, 1903)
This bumble bee species was not found in the Figueroa and Bergey 2013 survey. The last report of this species in our state was from the canola field study by Oklahoma State University Marvin Klemme Range Research Station and Stillwater Agronomy Station within the 2000–2013 time period (mentioned in Figueroa and Bergey 2015). The historical distribution for this bumble bee covered almost all of Oklahoma. This species can be easily confused with the American bumble bee due to the similar color pattern of hairs. At the Zoo, we found this bumble bee at Sanctuary Asia and at the Pick Family Garden.
On INaturalist there is a report from Garfield County with the label 06 April 2012 by Shaun Michael.
Two-spotted bumble bee
Bombus bimaculatus Cresson, 1863
The two-spotted bumble bee was considered extirpated from Oklahoma, with the last collected specimen record from 1999 (Figueroa and Berguey 2015, Williams et al 2014).
At the Zoo, we found the first individual on April 30th at the Sam Moore Aviary garden on Salvia flowers. We also saw this bumble bee at Sanctuary Asia and at the Devon Picnic Area, associated with the flowers of the chaste tree.
*There is a report on INaturalist for the species on Tulsa from June 13th, 2016, and some recent reports also on INaturalist for Oklahoma City, Norman, Tulsa, Broken Bow, and Sequoyah State Park.
Cameron, S.A., Lozier, J.D., Strange, J.P, Koch, J.B., Cordes, N., Solter, L.F. and Griswold, T.L. 2011. Patterns of widespread decline in North American bumble bees. Proceedings of the National Academy of Science (USA) 108(2): 662–667.
Figueroa, L. L., & Bergey, E. A. 2015. Bumble Bees (Hymenoptera: Apidae) of Oklahoma: Past and Present Biodiversity. Journal of the Kansas Entomological Society. 88, 418–429.
Hatfield, R., Jepsen, S., Thorp, R., Richardson, L. and Colla, S. 2014. Bombus fraternus. The IUCN Red List of Threatened Species 2014: e.T44937623A69001851. https://dx.doi.org/10.2305/IUCN.UK.2014-3.RLTS.T44937623A69001851.en. Downloaded on 25 July 2020.
Hatfield, R., Jepsen, S., Thorp, R., Richardson, L., Colla, S. and Foltz Jordan, S. 2015. Bombus pensylvanicus. The IUCN Red List of Threatened Species 2015: e.T21215172A21215281. https://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T21215172A21215281.en. Downloaded on 25 July 2020.
Jepsen, S., Evans, E., Thorp, R., Hatfield, R., and S. Hoffman Black. 2013. Petition to list the rusty patched bumble bee Bombus affinis (Cresson), 1863 as an endangered species under the U.S. Endangered Species Act.
MacPhail, V.J., Richardson, L.L. and Colla, S.R. 2019. Incorporating citizen science, museum specimens, and field work into the assessment of extinction risk of the American Bumble bee (Bombus pensylvanicus De Geer 1773) in Canada. Journal of Insect Conservation. 23, 597–611.
Richardson, L. L., K.P. McFarland, S. Zahendra, and S. Hardy. 2018. Bumble bee (Bombus) distribution and diversity in Vermont, USA: a century of change. Journal of Insect Conservation. 23, 45–62
Rowe, L. M., D. L. Cuthrell., and H. D. Enander. 2019. Assessing Bumble Bee Diversity, Distribution, and Status for the Michigan Wildlife Action Plan. Michigan Natural Features Inventory, Report Number 2019–33, Lansing, USA.
Thorp, R., E. Evans, S. Jepsen and S. Hoffman Black. Xerces Society. Rusty Patched Bumble Bee Bombus affinis. https://www.xerces.org/endangered-species/species-profiles/at-risk-invertebrates/bumble-bees/rusty-patched-bumble-bee Cited 07/25/2020
Williams, P.H., & Osborne, J.L. 2009. Bumblebee vulnerability and conservation world-wide. Apidologie. 40, 367–387.
Williams, P.H., Thorp, R.W., Richardson, L.L. and Colla, S.R. 2014. The Bumble bees of North America: An Identification guide. Princeton University Press, Princeton.