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lemon cuckoo bumble bee

lemon cuckoo bumble bee (Bombus citrinus)
Photo © Barbara C. Williams

Features and Behaviors

Color refers to “hair” color. Cuckoo bumble bees have a similar appearance to that of bumble bees, but female cuckoo bumble bees do not have a pollen basket on the hind legs. The queen’s thorax is mainly yellow and may have a black spot between the wing bases. The sides of her thorax are all yellow, and the tail is black. There may be some yellow on the middle abdominal segments. Her facial “hair” is mainly black. The wings are light brown. The male has a black tail tip, black head and a black spot or bar between the wing bases. His thorax is generally yellow as is about the front half of the abdomen.

The lemon cuckoo bumble bee feeds from a variety of flowering plants. Females are active from April through October. Males are active from June through October. This species is a social parasite of other bumble bees. Queens mate then overwinter and become active in about April. They begin activity later than bumble bee queens because they need to find an established bumble bee colony to take over. Once a cuckoo bumble bee queen does so, she kills all the eggs, larvae and pupae of the bumble bee and lays her own eggs. The cuckoo bumble bee offspring will be cared for by the bumble bee workers. The bumble bee queen stays in the nest, but she no longer lays eggs, and her colony will die off because it produces no new queens and males. The lemon cuckoo bumble bee is a social parasite of the common eastern bumble bee Bombus impatiens and the half-black bumble bee Bombus vagans in Illinois.

Illinois Range


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

Illinois Status: common, native