The more common insecticides used on pine needle scale are sprays, rather than systemics. Sprays are dependent on what stage of their life cycle the insects are in and must be determined by careful monitoring. Generally, the most effective is to spray during the "crawler" stage because they are more vulnerable at this early stage. Please see the excerpt below and follow the links to fact sheets with more information on management of this pest.
"Often, the most effective controls of pine needle scale are “crawler sprays,” insecticides applied to coincide with the vulnerable crawler stage of the insect. Many yard and garden insecticides are labeled for this purpose, including insecticidal soaps, Sevin, Permethrin, Orthene, cyfluthrin and various oils.
Apply crawler sprays shortly after egg hatch, which can be determined by monitoring. The small, rosy-colored crawlers are detected by shaking a branch over a piece of white paper. Try this survey when crawlers are expected to first appear, from late April to late May. If egg laying and crawler activity occurs over a period of several weeks, repeat applications of insecticides, particularly if short-lived residual treatments (soaps, oils) are used. To conserve natural enemies, avoid insecticides at other times in the life cycle of the scale.
On many plants, infestations are localized and can be controlled with spot sprays."
I have not used AzaMax, and I don't find anything that says this is any better than other products.
I hope this helps. Thanks for using our service.