Deluxe bumblebee nest box visited by cuckoo bumblebee
Cuckoos and their rather anti social behaviour are known to many people. Yet were you aware there are cuckoo bumblebees? Queen bumblebees emerging after hibernation may have to fight to the death with other queens in their search for a suitable nest site. The victor we shall call the foundress queen, who then sets about establishing her colony. There are other queens bumblebees who specialise in seeking out already established nests, these are the cuckoo bumblebees called Psithyrus.
These queens are born fighters, with their tougher, thicker body armour, which is not as flexible as their targets, (less chance of being stung in a weak spot), being equipped with stronger jaws and stings than other bumblebees. Not being equipped with pollen baskets, less hairs on her body to aid in collecting pollen, unable to secrete wax to make wax cells, they are not equipped to establish their own nests. Instead they seek out, by smell, find and kill foundress queens, along with any workers that attack her in defence of their nest. Then she will take over the nest, enslave the conquered workers to feed, tend and nurse her own young, all of whom are queens or males. None are workers and none participate in foraging for food to bring back to the nest.
The cuckoo bumblebee (Bombus vestalis) just could not figure out how to open the bumblebee ‘cat flap’, even as worker bees were entering and leaving and she watched! Of course she had not been trained!
Despite numerous attempts she could not get inside the nest box…this nest was saved. She goes trying to find another entrance.
The lawn near the bumblebee nest box was searched on foot, she then flew…..
into the ivy near to the nest searching in nooks and crannies…..
then goes to search the primroses nearby,for an alternative entrance…
After unsuccessfully spending some time in search of another entrance, this queen tries another method to gain assess to the bumblebee nest box….
a full on charge of the entrance, flying off in disgust for one last search…….
For the next two weeks I observed similar actions by a queen cuckoo bumblebee trying to gain access. Whether it was the same queen I will never know.
For more bumblebee information and to help save bumblebees join the Bumblebee Conservation Trust.
Refs: Besides my own experiences and observations;
Alford, D V (2009) ” The life of the bumblebee”, Northern Bee Books, Hebden Bridge, West Yorks.