We have a beautiful 4 year-old silk tree (Albizzia) with a classic umbrella shape and recently the upper surface of the leaves has become a magnet for bees,wasps,hornets etc.
Does anyone know what the attraction might be? It isn’t under other trees so I can’t see how "honeydew" might be falling on it, and no longer has blossom.
Check on the trunk and branches for scale insect.
They look like tiny limpets on the wood.
They will excrete honeydew, which will attract lots of other insects.
I couldn’t understand why the bees etc, were still around my black plum tree earlier this summer. The blossom had finished and the fruit was too young to attract anything.
I found loads of scale insects all over one part of the tree.
You cannot get rid of them at this time of year.
You can apply a winter wash in winter when the tree is dormant.
It would be best to google "dormant winter wash" to see what is available.