Skip to main content

rusty-patched bumble bee

rusty-patched bumble bee (Bombus affinis) [state and federally endangered]
Photo © Barbara C. Williams

Features and Behaviors

Colors refer to “hair” colors. The head is black. Workers and males usually have a rust-red patch on the back. The thorax is yellow, usually with a black spot or bar between the wing bases. The anterior abdominal segments of the queen are yellow. Males and workers have yellow on the anterior portion of the abdomen as well.

The rusty-patched bumble bee is a short-tongued bee. This species visits sunflowers (Helianthus spp.), asters (Symphiotrichum spp.), goldenrods (Solidago spp.), honeysuckles (Lonicera spp.) and many other flowering plants. It nests under the surface of the ground. Queens are active from April through October. Workers are active from June through October. Males are active from July through October. These bees are important pollinators of the flowers that they visit to collect nectar and pollen. Bumble bees 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 material. 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. Loss and degradation of prairie and grasslands habitats, pesticides, diseases, intensive farming and climate change have all been detrimental to the survival of this species.

Illinois Range


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

Illinois Status: state and federally endangered, native