Plants and Animals
Bombus auricomus Black and gold bumble bee
Key Characteristics
This is a relatively large species of bumble bee. Both workers and males are approximately 1.7 to 2.0 cm in length, while queens are 2.0 to 2.5 cm in length. Body hair is short and even. Ocelli are low on the face. Characteristics of queens and workers include black face with few scattered yellow hairs; top of head mostly yellow towards the back; thorax is yellow along the anterior and posterior sections, with a distinct black band between the wings; abdominal segments T2 and T3 are always yellow, and abdominal segment T1 is mostly black with occasional scattered yellow hairs intermixed; and remaining abdominal segments are always black. Males are similar to queens and workers except they tend to have more interspersed yellow hairs throughout, especially on abdominal segment T1, which can be completely yellow to predominately black. The face of males is mostly yellow, with scattered black hairs (Wallace and Webb 1962, Williams et al. 2014).
Status and Rank
US Status: No Status/Not Listed
State Status: SC - Special Concern (rare or uncertain; not legally protected)
Global Rank: G5 - Secure
State Rank: S2 - Imperiled
Occurrences
| County | Number of Occurrences | Year Last Observed |
|---|---|---|
| Allegan | 1 | 1964 |
| Barry | 9 | 2021 |
| Benzie | 1 | 1954 |
| Berrien | 3 | 2021 |
| Calhoun | 1 | 2021 |
| Cass | 3 | 2021 |
| Clinton | 1 | 1955 |
| Genesee | 1 | 1959 |
| Gratiot | 1 | 2021 |
| Hillsdale | 2 | 1975 |
| Huron | 1 | 1920 |
| Ingham | 4 | 2013 |
| Ionia | 5 | 2021 |
| Jackson | 5 | 2022 |
| Kalamazoo | 11 | 2023 |
| Kent | 3 | 2021 |
| Lenawee | 9 | 2020 |
| Livingston | 3 | 2020 |
| Macomb | 1 | 1937 |
| Monroe | 3 | 1976 |
| Montcalm | 3 | 2022 |
| Muskegon | 1 | 1930 |
| Oceana | 1 | 1934 |
| Ottawa | 1 | 2015 |
| Saginaw | 2 | 2019 |
| Shiawassee | 1 | 1948 |
| St. Joseph | 3 | 2021 |
| Van Buren | 1 | 2014 |
| Washtenaw | 5 | 2020 |
Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.
Habitat
This species favors prairies and grasslands and is rarely associated with extensive forests. Considered a foraging generalist, this bumble bee will regularly visit floral resources in dunes, marshes, forest edges, farmland, and urban areas. Known foraging resources include bergamots and horse-mints (Monarda spp., clovers (Trifolium spp.), thistles (Cirsium spp.), and vetches (Vicia spp.), among other species (Wood et al. 2019). Nests are usually underground, in old rodent burrows or tufts of grass where there is adequate space for colony development. This species can also occupy agricultural landscapes, however, associated pressures such as ground management and pesticides may restrict populations in these areas. Most Bombus queens overwinter in rotten wood or underground (COSEWIC 2010).
Natural Community Types
- Dry sand prairie
- Dry-mesic prairie
- Hillside prairie
- Lakeplain wet prairie
- Lakeplain wet-mesic prairie
- Mesic prairie
- Mesic sand prairie
- Prairie fen
- Southern wet meadow
- Wet prairie
- Wet-mesic prairie
- Wet-mesic sand prairie
For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.
Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.
Management Recommendations
As a foraging generalist, this species needs access to abundant and diverse floral resources. Managing landscapes to maximize season long availability of floral resources is necessary for colony health and reproduction. These actions may include protecting associated natural communities, planting wildflower plots, and incorporating prairie species into habitat management programs. Minimize ground disturbance in occupied habitats to help provide adequate nesting locations. This species may nest within forest edges. Populations found in these landscapes may be particularly sensitive to ground management actions, such as disking, tilling, and herbicide applications. Avoid daytime applications of pesticides (herbicides, insecticides, fungicides). If applications are required, apply in the evening when bumble bee activity is low, or do not apply in occupied habitat.
Active Period
Breeding from fourth week of August to fourth week of September
Flight from first week of June to fourth week of August
Nesting from first week of May to fourth week of June
Survey Methods
Surveys typically involve capturing foraging bumble bees with an aerial net and identifying the individual species (Colla and Packer 2008, Grixti et al. 2009). Observational surveys are also common, and generally require two to three high-quality photos for identification.
Aerial net, visual survey
Survey Period: From first week of May to fourth week of September
Time of Day: Daytime
Cloud Cover: Clear
Air Temperature: Above 60 degrees
Wind: No Wind
References
Survey References
- Colla, S.R. and L. Packer. 2008. Evidence for decline in eastern North American bumblebees (Hymenoptera: Apidae), with special focus on Bombus affinis Cresson. Biodiversity and Conservation 17: 1379-91.
- Grixti, J.C., L.T. Wong, S.A. Cameron and C. Favret. 2009. Decline of bumble bees (Bombus) in the North American Midwest. Biological Conservation 142: 75-84.
Technical References
- Colla, S.R. and L. Packer. 2008. Evidence for decline in eastern North American bumblebees (Hymenoptera: Apidae), with special focus on Bombus affinis Cresson. Biodiversity and Conservation 17: 1379-91.
- Colla, S.R., F. Gadallah, L. Richardson, D. Wagner, and L. Gall. 2012. Assessing declines of North American bumble bees (Bombus spp.) using museum specimens. Biodiversity and Conservation 21(14): 3585-3595.
- COSEWIC. 2010. COSEWIC assessment and status report on the Rusty-patched Bumble Bee Bombus affinis in Canada. Commitee on the Status of Endangered Wildlife in Canada. Ottawa. 34pp.
- Goulson, D. 2010. bumblebees: behavior, ecology and conservation. Second Edition. Oxford University Press, New York. 317pp.
- Grixti, J.C., L.T. Wong, S.A. Cameron and C. Favret. 2009. Decline of bumble bees (Bombus) in the North American Midwest. Biological Conservation 142: 75-84.
- LaBerge, W.E. and Webb, M.C., 1962. The Bumblebees of Nebraska: (Hymenoptera, Apidae, Bombinae). University of Nebraska. College of Agriculture. The Agricultural Experiment Station.
- 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.
- Williams, P.H., R.W. Thorp, L.L. Richardson, and S.R. Colla. 2014. Bumble bees of North America: an identification guide. Princeton University Press.
- Wood, T. J., J. Gibbs, K.K. Graham, and R. Isaacs. 2019. Narrow pollen diets are associated with declining Midwestern bumble bee species. Ecology, 100(6), e02697.