Pest on bay bay tree and skimmia

Hi- I'm not sure if this is a pest but it looks like one to me. The trunks of my largish bay bay tree and mature skimmia are covered in what look like tiny tortoise shells a few milimetres long. They are stuck to the bark with a white, fluffy substance and pull off easily. Is this a pest and, ifso, how should I get rid? Pull them off by hand?Spray with insecticide? The skimmia seems unaffected but the bay isn't doing well (although it was recently moved so it's poor growth may be due to other factors).
Any help much appreciated!
Thanks.
James

 

Its scale insect.
Just remove them by hand if thats possible.