By Tonigrogan
North Yorkshire,
United Kingdom 
I have 2 bay trees which have suddenly got white marks on the stem and branches. Can you please identify them and tell me how to remove it, if possible as they are quite established trees.
2 Jul, 2016
Answers
Thanks very much for your quick response. So it won't kill my Bays?
2 Jul, 2016
No I have had it on Bays and on Acers
2 Jul, 2016
No, the scale won't kill your bay trees, but if its a heavy infestation, it may weaken the trees and make them unsightly. If you have methylated spirits available, lightly moisten a disposable cloth with it, then rub the woody parts with the cloth to get rid of the scale. If the scale is present on the leaves, you shouldn't use this treatment on green parts, so that might mean you need to treat with an appropriate pesticide spray that treats for scale. More info regarding scale and treatments generally in the link below
https://www.rhs.org.uk/advice/profile?PID=224
2 Jul, 2016
You may need to add a surfactant to the pesticide to get it through the fuzz, and the scale's shell.
2 Jul, 2016
Scale insects I rub them of using a rubber glove quite sticky when removed spray with an insecticide
2 Jul, 2016