Cuckoo-bumble-bee
Guides
Bombus ashtoni
Ashton's cuckoo bumble bee
Bombus ashtoni is a cuckoo bumble bee (subgenus Psithyrus) native to North America. Unlike social bumble bees, this species does not produce workers or construct its own nests. Instead, females infiltrate established colonies of other Bombus species and exploit the host workers to rear their own offspring. This parasitic lifestyle has been documented specifically with hosts including Bombus affinis, Bombus terricola, and Bombus fervidus. The species is subject to the same conservation concerns affecting its host species, particularly the endangered rusty patched bumble bee (B. affinis).
Bombus flavidus
Yellowish Cuckoo Bumble Bee, Yellowish Cuckoo Bumblebee
Bombus flavidus is a widespread Holarctic cuckoo bumble bee and one of the most broadly distributed bumble bee species globally. As a social parasite, it invades colonies of other bumble bee species rather than building its own nests. Recent taxonomic research has clarified its status, synonymizing the former North American Bombus fernaldae with B. flavidus while recognizing an eastern North American subspecies, B. flavidus appalachiensis.
Bombus flavidus appalachiensis
A subspecies of the cuckoo bumble bee Bombus flavidus endemic to eastern North America, ranging from the Appalachian Mountains to the eastern boreal regions of the United States and far southeastern Canada. Described in 2021 following integrative taxonomic analysis that revealed this population as genetically and morphologically distinct from western North American and Palearctic populations. As a social parasite, this subspecies does not construct colonies or collect pollen but invades nests of other bumble bee species.
Bombus insularis
Indiscriminate Cuckoo Bumble Bee
Bombus insularis is a cuckoo bumble bee in the subgenus Psithyrus, native to northern and western North America. As a social parasite, it invades nests of host bumble bee species, usurps the resident queen, and exploits host workers to rear its own offspring. The species is known for its broad host range, attacking multiple bumble bee species across diverse habitats including tundra, taiga, and mountain ranges.
Bombus natvigi
High Arctic Bumble Bee
Bombus natvigi is a cuckoo bumble bee endemic to the Nearctic Arctic, recognized as a distinct species from Bombus hyperboreus in 2015 based on genetic analysis. It is a brood parasite that invades colonies of Bombus polaris, using pheromones to manipulate host workers into rearing its offspring. The species is currently listed as Data Deficient by the IUCN Red List, reflecting limited knowledge of its population status and ecology. Its taxonomic status remains debated, with some subsequent studies treating it as a subspecies of B. hyperboreus.