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 taxon, extant group in the tribe Bombini, though a few extinct r ...

genus '' Bombus''. Until the 1990s, ''Psithyrus'' was considered to constitute a separate genus.Williams, P.H. 1994. Phylogenetic relationships among bumblebees (''Bombus'' Latr.): A reappraisal of morphological evidence. Systematic Entomology 19: 327-344. They are a specialized socially parasitic lineage which parasitises the nests of 'true' bumblebees; they do not collect

pollen Pollen is a powdery substance produced by most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains (highly reduced Gametophyte#Heterospory, microgametophytes), which produce male gametes (sperm ...

or establish their own nests. Cuckoo bumblebees do not create a worker caste and produce only male and female reproductives. They are considered inquilines 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 branickii'' * '' Bombus campestris'' *''Bombus chinensis'' * '' Bombus citrinus'' *''Bombus coreanus'' * '' Bombus cornutus'' *''Bombus expolitus'' * '' Bombus fernaldae'' *''Bombus ferganicus'' * '' Bombus flavidus'' * '' Bombus insularis'' *''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 Psithyrus, cuckoo bumblebee, found in most of Europe and Russia. Its main hosts are ''Bombus pratorum'', ''Bombus jonellus'', and ''Bombus mo ...

'' *''Bombus tibetanus'' *''Bombus turneri'' * '' Bombus variabilis'' * '' Bombus vestalis''

Gallery

Bumblebee January 2008-4.jpg, '' Bombus vestalis'' 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