Sick tree?

Looking through my new book I bought this week 'What's Wrong with My Plant?' by Steven Bradley - it looks like Brown Scale - Parthenolecanium corni, small brown blisters 1 - 6mm on stems and leaves. They suck the sap which gradually weaken the plant. He suggests treating it with the parasitic wasp Metaphycus helvolus, a preditor insect, in midsummer. Hope I'm right.

I agree. They are otherwise known as scale insects. They are hard to get rid of, I'm afraid. I had them on my Pyracanthas and in the end got rid of the Pyracanthas!