Tree Bumblebees

Tree bumblebees, Bombus hypnorum, were the main topic of conversation on the Bumblebee Conservation Trust stand at RHS Chatsworth last week. I last blogged about them in 2013, but it seems there’s a need to get more information out!

Bombus hypnorumBoth the BBCT and the BBKA (the British Beekeepers’ Association) are swamped by people asking for help with honeybee swarms, which turn out to be Tree Bumblebee nests. I get calls here too as I’m on the local swarm collection list. As the name suggests, Tree Bumblebees nest… in trees. Failing that, birdboxes or small holes in eaves make lovely snug nests for them. This is unlike our other bumblebees, which nest underground. It’s also unlike honeybees, which need bigger spaces to make colonies in.

It’s unusual for a bumblebee, and its behaviour fools many. Tree bumblebees are new arrivals, driven here by climate change around 2000/2001. They’re thriving, and are now one of the “big eight” of common bumblebees in the UK. Combine this with the cloud of drones which whizz around outside the nest entrance, and their habit of nesting in more obvious locations, and lots of people reach for the phone.

Please don’t! A honeybee swarm is quite different. The bees look very distinctive and there will usually be many, many more of them. Tree Bumblebees might look black from a distance, but they are actually a very smart brown, black and white. Like all bumblebees, Tree Bumblebees will nest for a season, so they’ll only be a temporary nuisance if they’re in the way. And they’ll help pollinate your fruit and veg!