Here's a new one, anybody else have these sort of 'blisters' on the leaves of cattleyas? They are raised, turn brown, dry and split but they don't seem to do much damage and the leaves don't die. The blister does't go all the way through the leaf either. I have this randomly on one or two leaves on several plants. Second pic, those are not water droplets, they are the beginnings of the blisters.
I carefully opened one with sharp tweezers, and looked at it under my dinky microscope, and there is no sign of insects or other inhabitants.
