Host-dependent
Guides
Bombus variabilis
Variable Cuckoo Bumble Bee, Variable Cuckoo Bumblebee
Bombus variabilis is a parasitic bumble bee (subgenus Psithyrus) native to North America. It lacks the ability to collect pollen or establish its own colonies, instead infiltrating nests of host bumble bees to reproduce. The species is critically dependent on Bombus pensylvanicus as its primary host, making its survival tightly linked to host population trends. Bombus variabilis has experienced significant decline due to habitat loss and climate change affecting its host.