Social Parasitism

Cuckoo Bumblebees — Usurping host colonies by deception and force

Colony Composition

Host queenPresent
Host workers0
Host brood0
Parasite queenAbsent
Parasite brood0

Invasion Status

PhasePre-invasion
Host queen aliveYes
Worker loyalty100%
Colony outcome--

Mechanism

Psithyrus (cuckoo bumblebees) enter established host colonies, often killing the host queen. They produce chemical mimics of host queen pheromones and may physically suppress worker reproduction. Workers are tricked into raising parasite offspring instead of their own queen's brood.