Bumblebees swarming outside of bumblebee nests.....why?

3 posts / 0 new
Last post
nurturingnature
Offline
Last seen: 4 months 19 hours ago
Joined: 23/05/2013 - 13:02
Bumblebees swarming outside of bumblebee nests.....why?

I had never seen nor heard of bumblebees swarming before outside bumblebee nests. Being B. hypnorum I assumed it was something to do with their defensive behaviour of their nests! Wrong! ...... see video here http://bit.ly/1buMTJW

Stuart Roberts
Offline
Last seen: 5 days 42 min ago
Joined: 15/12/2011 - 12:19
"Swarming"

There has been quite a lot of discussion of this since the first reports several years ago (see the BBCT website). What seems to be happening is that freshly emerged males swarm around the nest entrances waiting for the emergence of virgin queens.

What I have observed has included activity of B. hypnorum males all around a nest of B. pratorum, and at a nest of B. hypnorum in my own garden, males of B. pratorum (along with hypnorum) buzzing the entrance. Given that the two species are both members of the subgenus Pyrobombus, it would seem that the attractant pheromones must be quite similar chemically.

nurturingnature
Offline
Last seen: 4 months 19 hours ago
Joined: 23/05/2013 - 13:02
Swarming B. hypnorums

Thanks Stuart. I have observed the females being pounced upon my males as soon as they leave the nest. Quite often the pouncing bowls the queens to the floor. Other times she continues to fly. I have also observed queens returning to the nest with the males still attached to her and she enters the nest
with him. Whether he leaves unscathed or attacked inside I cannot say.

My other nest, 15 feet away has had swarming as video shows, yet I have not seen queens emerging as I did with the other nest. I know the signs now of queens emerging and the signs are today evident. I await further evidence!

Log in or register to post comments