small pinholes on many of my plants leaves

Hello, I seem to have this issue on a number of my plants, all the maples, lilacs and hydrangeas and I am sure a few more but you'll get the idea from these photos, does anyone know if this is a heat/drought issue or a pest?

In a possibly related matter I have really bad scale fro the first time in 11 years since i have been here, it has totally infested my 2 pieris and moderately affected a nearby rhodo and camelia and one hydrangea clear across the yard. I also saw a bit on a holly.
I do not want to have to remove the pieris as it is very mature and nice, but I have sprayed it with end all 4 times and it keeps coming back. I now use the water gun to manage it but I am not keeping up and its time consuming, any ideas?

Late winter /early spring I notices white blotches on all my trees so I used "defender" spray while still dormant in case that is also related.


Thanks in advance.