What are these clusters of black bugs on my cherry tree leaves?

[tealsofas]

About a month ago we had shot-hole disease due to watering the garden with a sprinkler. I treated the leaves with a fungicide and while we do still have some leaves with shot holes, it’s got better.

Now we’ve just noticed these bugs.

This tree is destined to fail isn’t it 😭

Just don't buy ladybirds if you have ants farming, they kill the ladybirds we found last year 😫

We get this, and greenfly. Spray tee with a soapy water mixture (helps the bugs to slide off the leaves) and then hose down after. May need doing a couple of times but really helps.