Can anyone id this thing is that is eating my peach tree leaves......?

I've soaked the leaves multiple times with neem oil and it doesn't seem to affect them.  Hit them with 7 Dust and I think it may have stopped them.  I am curious to what they are.  They are only on the peach trees from what I can see.  The plum, apple, and cherries seem to be devoid of them. They decimated my new peach trees in short order.  The weird thing is that 6 other much older peach trees don't appear to have the things on them either.  They seem to be primarily on the underside of the leaves.  This pic was taken on macro settings through a magnifying glass.  The, whatever it is, is resting on the tip of a very small jewelers screwdriver for reference.  Many thanks in advance for any help offered.....

Hi Pat!
welcome to these forums!

Without seeing the leaves with the damage I'm guessing leaf miners although you say the damage is mostly underneath the leaf?
I've never considered them a problem.

Nice photo of the culprit though.

7's dust is nasty stuff and not at all organic....we're just looking for and discussing organic or better solutions here😊

Sample of leaves.  I plucked the really bad ones off. As for organic solutions....Like I said previously,  I used neem oil extensively to no avail.