I have been so hopeful since I eradicated my long-running cottony-cusion-scale problem that I might be able to get rid of the mealybugs also. So far they have been very resilient, the neurotoxic pesticides don't seem to work well on them, and coverage with smothering agents is always tough.
The armored scale have been pretty isolated, not sure why. I haven't seen them on my citrus trees yet, only a few other tropical fruit trees.