Ash leaf damage
I found this today on a tree that has been in the yard for over 15 years. It is 'Autumn Purple' ash (Fraxinus americana 'AP'). I have seen all of the typical maladies - flatheaded apple borer, ash/lilac borer, eastern twig borer (no EAB yet!), ash flower gall mite, etc. but this is the first time for this leaf mining insect. Two things that may or may not play on this - the damage seems much more prevalent on the north side of the tree (both pix from that side) and lowest, most shaded foliage; also I spotted two or three extremely fast black gnat like insects about 3/16" long. They were speedy both flying and leggin' it across the foliage.
Any ideas? TIA.