Wi BBB: Bombus borealis

photo of Gyne on butter-and-eggs (<em>Linaria vulgaris</em>) — Gyne on butter-and-eggs (*Linaria vulgaris*) — Jay Watson

The northern amber bumble bee is found northern U.S. and southern Canada. While uncommon, it does not seem to be declining (Hatfield et al. 2015). Wisconsin has several recent observation records from northeastern and central counties. Older records are found scattered through the northern two thirds of the state.

The northern amber, like other bumble bees, live in colonies composed of a single queen and female workers. Colonies start to produce new queens and males in the mid- to late summer. Only new, mated queens overwinter, emerging from diapause (a form of hibernation) in the spring. New queens are responsible for finding a new nest site, laying eggs, and for all of the foraging and care of the colony until the first workers emerge (Hatfield et al. 2015). Once the first workers emerge, the queen remains in the colony laying eggs. Bumble bees need areas that provide nectar and pollen from flowers throughout the duration of the colony life cycle, and suitable sites for nesting and for overwintering queens.

Status-Global/State:

Global: G4G5 Wisconsin: S3

image showing reference locations of body parts

Identification:

Worker – Face and vertex mostly yellow. Thorax with black band between the wingpads and on the lower sides. Abdominal segments T1-4 yellow, T5 usually mostly black and T6 black; sometimes has intermixed black on the sides on T2-4 and fringe of yellow on T5-6.
Queen/gyne – Similar to workers, but are larger and appear earlier in the season.
Male – Similar to workers. Abdominal segments T5-6 can be all black, or with fringes of yellow.
Other distinguishing features – Hair medium and even.

Similar Wisconsin Species:

Similar bumble bee species in Wisconsin are the American bumble bee (B. pensylvanicus) and the yellow bumble bee (B. fervidus) (Colla et al. 2011, Williams et al. 2014).

Description of Habitat/Range:

Known habitats include woodlands, and nests are primarily underground (Williams et al. 2014).

Nectar Plants

The northern amber is a long-tongued species (Williams et al. 2014). Nectar plants include Asters, Astragalus (milk vetch), Carduus, Cirsium (thistles), Eupatorium (Joe-pye weed), Melilotus (sweet clover), Prunella, Rubus (blackberry), Solidago (goldenrods), Symphytum officinale (comfrey), Trifolium (clovers), and Vicia (vetches) (Williams et al. 2014, Colla et al. 2011).

Click on the legend symbols for each type of bumble bee to add or remove them from the graph.
Data from verified B3 observations [updated 2/28/2024].

Flight Season:

In Wisconsin, observations have been reported mostly between June and September. Range-wide, queens start emerging in May and enter diapause in October (Colla et al. 2011).

Literature Cited:

Colla, S., Richardson, L. and Williams, P. (2011) Bumble Bees of the Eastern United States. A product of the USDA Forest Service and the Pollinator Partnership with funding from the National Fish and Wildlife Foundation.

Hatfield, R., Jepsen, S., Thorp, R., Richardson, L. & Colla, S. 2015. Bombus borealis. The IUCN Red List of Threatened Species 2015: e.T44938377A46440336.

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.

Gyne on butter-and-eggs (Linaria vulgaris) — Jay Watson