Hello, we have two apple trees and a plum tree showing the bumps and white insects (?) shown in the attached pictures. They are around 3 years old, we never got any fruit and they had that last year too. It seems like a whole bunch of trees along the sidewalk in the neighborhood have that too... Is that scale insects? Is that treatable? What will happen if we treat our trees but the neighborhood's trees are not treated? Is it just going to come back all the time? Thank you for your help!! Best, Roxane Alles