My young 5' blue spruce has some black growths formed on the twig nodes. It has no healthy buds. I'm not sure whether it's a sign of spruce bud scale, sooty mold, bud blight or else. Once I noticed this issue, a few weeks ago, I applied the granular systemic insecticide (0.550% Imidacloprid; 0.275% Clothianidin). I also sprayed the tree with horticultural oil. I would like to confirm what type of disease it is and whether or not it's treatable at this stage. If recovery is possible, what is the recommended treatment plan? Any suggestions would be greatly appreciated. Thank you.