Wi BBB: Bombus impatiens

photo of Worker on Russian sage (<em>Perovskia atriplicifolia</em>) — Worker on Russian sage (*Perovskia atriplicifolia*) — Jay Watson

The common eastern bumble bee is found throughout the northeastern U.S. and adjacent southern Canada. It is considered widespread and abundant and is possibly expanding in its range (Williams et al. 2014). Wisconsin has many current records from the southern half of the state. Historic records are from across the state.

The lemon cuckoo bumble bee (B. citrinus) is a nest parasite of the common eastern bumble bee (Williams et al. 2014). The lemon cuckoo has few Wisconsin records.

The common eastern bumble bee, 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. 2014). 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: G5 Wisconsin: S5

image showing reference locations of body parts

Identification:

Worker – Face black and vertex yellow. Thorax yellow with faded black spot/patch. Abdominal segment T1 yellow, and T2-5 and T6 black. Very rarely some morphs have some yellow in the front near the center of T2.
Queen/gyne – Similar to workers, but are larger and appear earlier in the season. Some morphs have a completely yellow thorax, some have yellow in the center of T2, and a rare morph has yellow intermixed on the sides of T4-5.
Male – Similar to workers except with lighter face.
Other distinguishing features – Large bee with short and even hair and square cheek/face.

Similar Wisconsin Species:

Similar bumble bee species in Wisconsin are twospotted bumble bee (B. bimaculatus), brownbelted bumble bee (B. griseocollis), confusing bumble bee (B. perplexus), Sanderson's bumble bee (B. sandersoni), and half-black bumble bee (B. vagans) (Colla et al. 2011, Williams et al. 2014).

Description of Habitat/Range:

Found in a variety of habitats across its range including woodland, grassland, farm field, urban parks, wetlands, and gardens (Hatfield et al. 2014, Williams et al. 2014). Nests have been found underground in open fields and woods (Hatfield et al. 2014).

Nectar Plants

The common eastern bumble bee is a medium-tongued species (Williams et al. 2014). Nectar plants include Aster, Cirsium (thistles), Eupatorium (Joe-pye weed), Gelsemium, Impatiens, Malus, Pontederia (pickerel weeds), Rubus (blackberry), Solidago (goldenrods), and Trifolium (clovers) (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 between April and October. Range-wide, queens start emerging in April 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. 2014. Bombus impatiens. The IUCN Red List of Threatened Species 2014: e.T44937797A69003246.

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.

Worker on Russian sage (Perovskia atriplicifolia) — Jay Watson