Posted: 04/05/2015 at 11:09
I also think it's likely scale insect, probably Brown Scale. RHS control advice here:
With a reasonably small tree like that I would rub them off by hand. At this time of the year, underneath each one will be hundreds of eggs (that's the white waxy stuff peeping out at one end of each scale.) In about June these will hatch and run all over the tree, so tackle it now.