Bombus rufocinctus

Cresson, 1863

red-belted bumblebee

Bombus rufocinctus, commonly known as the red-belted bumblebee, is a North American characterized by striking color in abdominal patterning. Queens measure 16-18 mm, 11-12 mm, and males 12-13 mm. The species inhabits wooded areas, urban parks, and gardens across Canada and the western, midwestern, and northeastern United States. Males exhibit perching and possess cephalic labial glands that secrete complex chemical mixtures likely involved in mating signaling. Nests are typically constructed on or above ground level.

Bombus (Cullumanobombus) rufocinctus by the Smithsonian. Used under a CC0 license.

Pronunciation

How to pronounce Bombus rufocinctus: //ˈbɒm.bəs ru.ˈfoʊ.sɪŋk.təs//

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Identification

Identification is complicated by four distinct color morphs resulting from genetic . The combination of red and/or black on 2-3 with yellow and/or black on terga 4-5 creates variable appearances that may resemble other Bombus . Size dimorphism between is pronounced: queens (16-18 mm) are distinctly larger than and males (11-13 mm). Microscopic examination of male genitalia or molecular methods may be necessary for definitive identification in some cases. The species can be distinguished from the similar B. ternarius (tricolored ) by the more variable and less sharply defined banding pattern.

Images

Habitat

Wooded areas and forest edges; also occurs in urban parks and gardens. Nests are constructed on or above ground level, including in grass tussocks, rock piles, and man-made structures. Shows adaptability to anthropogenic .

Distribution

Native to North America with wide distribution across Canada and the western, midwestern, and northeastern United States. Presence in Mexico is possible but not firmly established.

Diet

forager on diverse flowering plants. Documented floral include chicories (Cichorium), snakeroots (Ageratina), strawberries (Fragaria), gumweeds (Grindelia), sunflowers (Helianthus), goldenrods (Solidago), clovers (Trifolium), vetches (Vicia), and goldeneyes (Viguiera). Short-tongued influences foraging choices.

Life Cycle

Eusocial colony cycle with queens founding new colonies in spring. Colonies produce , then males and new queens. Specific not documented in available sources.

Behavior

Males exhibit perching on vegetation, likely associated with mate-searching. Males possess cephalic labial glands that secrete -specific chemical mixtures dominated by 3,7,11,15-tetramethyl-2,6,10,14-hexadecatetraenyl acetate, along with hydrocarbons, isoprenoids, and derivatives; these secretions are probably used for mating-related signaling. Short-tongued foraging restricts access to certain flower types.

Ecological Role

of wild flowering plants and agricultural crops. As a forager, likely contributes to pollination networks across diverse plant . Buzz pollination capability (inferred from -level trait) may benefit certain plant .

Human Relevance

Occurs in urban parks and gardens, providing pollination services in anthropogenic landscapes. Potential of cultivated strawberries and other crops. Subject to general threats affecting bumble bees including alteration, , and climate change.

Similar Taxa

Bombus ternariusSimilar tricolored appearance with red abdominal banding; distinguished by more consistent, sharply defined yellow-black-red banding pattern and lack of the extensive color seen in B. rufocinctus
Bombus rufocinctus color morphsThe four genetic color morphs of this can resemble each other and different Bombus species; reliable identification requires attention to the specific tergal pattern combinations

More Details

Chemical ecology

Male cephalic labial gland secretions have been chemically characterized, revealing complex mixtures including the major compound 3,7,11,15-tetramethyl-2,6,10,14-hexadecatetraenyl acetate, saturated and mono-unsaturated hydrocarbons, isoprenoid hydrocarbons (β-springene, α-springene isomers), cyclic diterpenes, and characteristic alcohols (9-hexadecenol, hexadecanol, 9-octadecenol) with their acetates and .

Color polymorphism genetics

Four distinct color morphs are genetically controlled, involving independent variation in 2-3 (red or black) and terga 4-5 (yellow or black). This creates phenotypic variation that complicates field identification and may represent adaptive or neutral genetic variation.