Moni

If you are sure that it is scale, there are a number of ways you can deal with them. You can use alcohol or mineral oil on a cotton swab and wipe them off. Insecticidal soap often works on scale as do the "summer" horticultural oils. If you want to get into heavy duty chemicals, you can try Dursban (if you can find it. This has been banned by the FDA), DuraGard (Chlorpyrifos),Tempo (cyfluthrin), Marathon (imidacloprid), Orthene (probably the easiest one to find), or Topcide (lambda-cyhalothrin). The main problem with using these "heavier" chemicals, besides the danger of toxicity, is that they need to be applied when the scale is in its crawler stage. This is usually in the spring or early summer but it can be hard to tell exactly. That is why the horticultural oils are so handy. Personally, if this were my tree, I would first remove what scale I could see with the cotton swab method and I would then spray with either hort. oil or insecticidal soap.
Good luck.
Moni