Skip to main content

half-black bumble bee

half-black bumble bee (Bombus vagans)
Photo © Rob Curtis, The Early Birder

Features and Behaviors

Wings are clear with black veins. Coloration is somewhat variable. Queens and workers have yellow “hair” on the thorax, first two abdominal segments and sides of the thorax. There is a black spot between the wing bases that may be large enough in the workers to reach the wing bases. The remainder of the abdominal segments have black “hair.”

These insects are medium-tongued bees. They nest on or under the surface of the ground. Unlike many bumble bee species, the half-black bumble bee can be found in forests. It is often seen at beardstongues (Penstemon spp.), milkweeds (Asclepias spp.), asters (Symphyotrichum spp.), thistles (Cirsium spp.) and thoroughworts (Eupatorium spp.). Queens are active from April through October. Workers are active from May through September. Males are active from June through October. These bees are important pollinators of the flowers that they visit to collect nectar and pollen. They are eusocial insects. Their life cycle includes egg, larva, pupa and adult stages. Only the fertilized queen overwinters from a colony. In the spring, she selects a nest site and constructs the nest, which is lined with plant materials. The first brood raised consists of all workers (females). The workers do all the jobs of the hive except egg‐laying. Late in the year both males and queens are produced. Males mate with queens in the fall.

Illinois Range


​Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Apidae