Tree Bumble Bees

The roses in our front garden are particularly lovely this year. They're ramblers of some kind, with a simple open flower that comes in clusters, looks sweet, and smells sweeter. This year they've been festooned with bees, that I've identified as tree bumble bees. These are a new species to Britain, first identified I think in 2001, but they've spread very rapidly across the whole of England and a good chunk of Wales, and into Scotland too. At a time when our bee population is under threat, a new species has to be good I think, and scientists tell us that there's no evidence the tree bumble bee's spread is harming other species.

The tree bumble bee likes to nest in holes in trees, as its name suggests. One reason for its spread across the UK is that nest boxes will do just as well, and it has even been known to evict the existing avian tenants in order to take over. I don't know where the ones we have are coming from, but they don't seem to be nesting on our premises. They like to come to our rose when it's in shade, there aren't anything like as many about when it's in full sun. I've seen them on one of our fuschias too, but they clearly like the rose better than anything else we've got. The wide open flowers will help. These bees don't like tubes like foxgloves, unlike many other bees. It's interesting to see where different species go. Our cistus - white open flowers like the rose - doesn't attract tree bumble bees, but instead has lots of visits from solitary bees of some species, black and honey bee shaped.

The tree bumble bees have a fluffy russet thorax, often with a black mark in the centre, then a black abdomen and a white tail. They vary in size, depending on the role they play in the colony, but none of them are all that big. They do seem to be very active and hard working bees. I'm glad to have identified them, and glad too that bees of all kinds have certainly benefited from the good start we've had to the summer.