When is a Bumblebee Not a Bumblebee? When it’s a Cuckoo Bumblebee!
Just when you thought identifying bumblebees was easy, now to complicate things. If, when out in the garden looking at bumblebees, you come across one that doesn’t match up to the identification book then chances are you have seen a cuckoo bumble. And no, as the children always ask at talks, it does not go “cuckoo cuckoo”, but it does take over the nest of other bumblebees and lays its eggs.
There are six species of cuckoo bumblebee – two of which often occur in gardens. It is thought that they have evolved from the bumblebee to live a different way. The queens emerge in the spring to feed up before looking for a nest to take over. After finding one the queen will hide in the nest for a day or two, which helps her to get the smell of the colony and become accepted and not attacked by the nest’s workers.
Then she tackles the queen whose nest it is. They fight each other and the cuckoo bumblebee usually wins the fight as she has evolved a thicker body shell that can withstand the stings of the other queen, who is killed or gives in. She then lays her eggs and the unsuspecting workers set to caring for them and accepting them as their own. Strange but true – the insect world is a complicated world. The life of a bee is not straightforward.
Cuckoo bumblebees differ in appearance from their hosts, being not as attractive, less hairy and having less noticeable yellow bands especially on the tail end and are much more lethargic when moving around, often crawling from flower to flower rather than ‘busy as a bumblebee’ – flying quickly from one to another.