Gypsy Cuckoo Bumblebee.

The Gypsy Cuckoo Bumblebee Bombus bohemicus, parasites the nest of the White-tailed Bumblebee.It is  widespread in the UK but tends to be more common in the north.

BWARS states that; After emerging from hibernation during April the mated female seeks out  a B. lucorum nest containing a few workers.The female enters the nest and hides until it acquires the nest scent.It then kills or dominates the host queen and begins to lay eggs.Only B. bohemicus male and female eggs are hatched although all work in the colony is done by the host workers.