The Collaborative International Dictionary of English v.0.48:
cuckoo-bumblebee \cuckoo-bumblebee\ n. 1. a bee that is parasitic in the nests of bumblebees. [WordNet 1.5] cuckoopintWordNet (r) 3.0 (2006):
cuckoo-bumblebee n 1: a bee that is parasitic in the nests of bumblebees