Victoria plum tree , brown bumps on branches

[divvy]

I have just been out to look at my one vic plum I have this year , last year I had about 20 , and I noticed brown bumps on the branches , they were easy to rub off and had off white powder inside . I rubbed all of them off that I could see , most of the branches has some on, always on the underside of the branch . Anyone know what they are please.

[FB.]

Scale insects?

[peanut]

I had Scale insects on my Victoria for the first time this year.....until i squished them!