Bombus griseocollis (Brown-belted Bumble Bee)

Species Overview

• Scientific name: Bombus griseocollis

• Common name: Brown-belted Bumble Bee

• Family: Apidae

• Range: Widely distributed across most of the United States and southern Canada; common in the Midwest, including Chicago.

• Identification: Medium-sized bumble bee with a short to medium tongue. Queens and workers are mostly black with a yellow thoracic collar and a brownish or rust-colored band on the second abdominal segment. Males are more yellow with variable brown markings.

Ecological Role

Pollinator

• Generalist forager visiting a wide range of wildflowers and crops.

• Particularly important for buzz pollination (vibrating flowers to release pollen), benefiting plants like tomatoes, peppers, and native Solanum species.

• Highly effective at pollinating prairie plants, asters, goldenrods, and legumes.

Food web link

• Adults feed exclusively on nectar and pollen.

• Larvae rely on stored pollen provisions in the nest.

• Serve as prey for crab spiders, birds, and predatory insects; nests may be raided by skunks or other mammals.

Ecosystem indicator

• Though relatively adaptable, their abundance can reflect the quality of habitat and floral diversity in an area.

Lifecycle in Chicago

Annual colony cycle; active from April through October

1. Spring – Queen emergence

   • Mated queens overwinter in loose soil, leaf litter, or grassy tussocks.

   • In April–May, they emerge and search for a nesting site (often abandoned rodent burrows or grass clumps).

2. Nest establishment

   • Queen gathers nectar and pollen, forms a wax pot, lays initial eggs.

   • First brood emerges as workers, taking over foraging and nest maintenance.

3. Colony growth

   • Through summer, the colony can reach 50–200 workers.

   • Workers collect pollen/nectar from a broad array of plants.

4. Late summer – Reproduction

   • Queen lays eggs that develop into new queens and males.

   • Males leave the nest to mate with queens from other colonies.

5. Colony senescence and overwintering

   • By fall, the founding queen, workers, and males die.

   • Newly mated queens enter diapause in sheltered ground until the next spring.

Best Native Host Plants to Support B. griseocollis in Chicago

Because they are generalist foragers, providing continuous bloom from spring to fall is key.

Early Spring (April–May) – queen foraging

• Salix discolor (Pussy Willow)

• Amelanchier arborea (Serviceberry)

• Prunus americana (American Plum)

• Zizia aurea (Golden Alexander)

Summer (June–August) – peak worker activity

• Monarda fistulosa (Wild Bergamot)

• Echinacea purpurea (Purple Coneflower)

• Rudbeckia hirta (Black-eyed Susan)

• Pycnanthemum virginianum (Virginia Mountain Mint)

• Asclepias tuberosa (Butterfly Weed)

• Dalea purpurea (Purple Prairie Clover)

• Ratibida pinnata (Yellow Coneflower)

Late Summer to Fall (August–October) – new queen provisioning

• Solidago rigida, S. speciosa, S. juncea (Stiff, Showy, and Early Goldenrods)

• Symphyotrichum novae-angliae (New England Aster)

• Symphyotrichum laeve (Smooth Blue Aster)

• Helianthus maximiliani (Maximilian Sunflower)

Habitat Support Tips

• Provide floral continuity: at least three native species blooming in each season.

• Preserve undisturbed soil, grassy tussocks, and leaf litter for overwintering queens.

• Avoid pesticides, especially neonicotinoids, which can harm both queens and workers.

• Leave some open, sunny, undisturbed ground for potential nest sites.