Cuckoo bumblebees are members of the subgenus ''Psithyrus'' in the

bumblebee A bumblebee (or bumble bee, bumble-bee, or humble-bee) is any of over 250 species in the genus ''Bombus'', part of Apidae, one of the bee families. This genus is the only extant group in the tribe Bombini, though a few extinct related gener ...

genus ''

Bombus A bumblebee (or bumble bee, bumble-bee, or humble-bee) is any of over 250 species in the genus ''Bombus'', part of Apidae, one of the bee families. This genus is the only extant group in the tribe Bombini, though a few extinct related gener ...

''. Until recently, the 28 species of ''Psithyrus'' were considered to constitute a separate genus. They are a specialized socially parasitic lineage which parasitises the nests of 'true' bumblebees, resulting in the loss of the ability to collect

pollen Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...

and establish their own nests. Cuckoo bumblebees do not create a worker caste and produce only male and female reproductives. They are considered

inquilines In zoology, an inquiline (from Latin ''inquilinus'', "lodger" or "tenant") is an animal that lives commensally in the nest, burrow, or dwelling place of an animal of another species. For example, some organisms such as insects may live in the h ...

in the colonies of 'true' bumblebees. Cuckoo bumblebee females emerge from hibernation later than their host species to ensure that their host has had sufficient time to establish a nest. Before finding and invading a host colony, a ''Psithyrus'' female feeds directly from flowers until her ovaries are sufficiently developed, at which time she begins seeking a nest to invade. Once she has located and infiltrated a host colony, the ''Psithyrus'' female usurps the nest by killing or subduing the host queen. She then lays her own eggs, exploiting the host workers to feed her and her developing young through pheromones and/or physical attacks.

Selected species

* '' Bombus ashtoni'' * '' Bombus barbutellus'' *''Bombus bellardii'' * ''

Bombus bohemicus ''Bombus bohemicus'', also known as the gypsy's cuckoo bumblebee, is a species of socially parasitic cuckoo bumblebee found in most of Europe with the exception of the southern Iberian Peninsula and Iceland. ''B. bohemicus'' practices inquilini ...

'' *''Bombus branickii'' * '' Bombus campestris'' *''Bombus chinensis'' * '' Bombus citrinus'' *''Bombus coreanus'' * '' Bombus cornutus'' *''Bombus expolitus'' * '' Bombus fernaldae'' *''Bombus ferganicus'' * '' Bombus flavidus'' * '' Bombus insularis'' *''Bombus monozonous'' *''Bombus morawitzianus'' *''Bombus norvegicus'' * '' Bombus quadricolor'' * '' Bombus rupestris'' *''Bombus skorikovi'' * '' Bombus suckleyi'' * ''

Bombus sylvestris ''Bombus sylvestris'', known as the forest cuckoo bumblebee or four-coloured cuckoo bee, is a species of cuckoo bumblebee, found in most of Europe and Russia. Its main hosts are '' Bombus pratorum'', '' Bombus jonellus'', and '' Bombus monticola' ...

'' *''Bombus tibetanus'' *''Bombus turneri'' * ''

Bombus variabilis ''Bombus variabilis'' is a critically endangered species of cuckoo bumblebee. ''B. variabilis'' is a parasitic species. Females kill and replace the queens of '' B. pensylvanicus'', taking over their nests in the process. The decline of the la ...

'' * ''

Bombus vestalis ''Bombus vestalis'', the vestal cuckoo bumblebee, is a species of cuckoo bumblebee that lives in most of Europe, as well as North Africa and western Asia. It is a brood parasite that takes over the nests of other bee species. Its primary host is ...

Gallery

Bumblebee January 2008-4.jpg, ''

'' Psithyrus insularis.jpg, '' Bombus insularis'' Bombus rupestris - Trifolium pratense - Keila.jpg, '' Bombus rupestris'' Bombus norvegicus - Veronica spicata - Keila.jpg, '' Bombus norvegicus'' Bombus sylvestris male - Cirsium palustre - Keila.jpg, ''

Selected species

Gallery

References

Further reading