Bombus hypnorum feeding on sap

[Africa]

There is a humming noise coming out of my cherry tree but it has no flowers. The tips of the new growing branches are covered on black aphids and are quite sticky with sap. The humming noise comes, as I found this morning, from Bombus hypnorum bumblebees. It was quite high and I couldn't get a good shot. I will keep trying. Has this been reported before? I had only seem Bombus terrestris doing this in my garden before.

[Jason Green]

Saw the same myself this morning! I believe mine was B. lucorum. The black aphids have made a real mess on a plant in my garden and the sap is everywhere, dripping onto weeds below, the leaves are all sticking together and curling round... It was nice to see a bee taking an interest though!

I'll try and get a photo if he returns...

[Paul mabbott]

Bees and other insects quite commonly take honeydew - aphid urine which is, in effect, concentrated sap - very sugar-rich.