Hi David @davewrightjoinerygooglemail.co I've done some research and had a closer look at this photo. Unfortunately it looks like Scale Insect which is a parasitic (to plants) insect. It can be treated with a chemical or organic spray which is good news.
Oh no that's terrible Jojo @jostarbuck Mines ok at the moment but I need to do something or lose it too. Did a bit of research online and found Neem oil might work plus its organic so won't harm bees, butterflies etc.