What is the plant? Can you show a picture of the whole plant?

interesting pic...

are we just talking about the indentations...

or also the yellowing.. or is that a light trick/??

ken

Only indentations. Healthy young tree otherwise.

Just plain flashlight from top in the dark. The damage done by something eating just the flesh surface of the leaf. I thought it might be a job by  skeletonizer but don't they only eat grape leaves?

Could you provide pictures taken in daylight?

What type of tree is that? I am thinking by fall most leaves kn most of my trees have some damage.

To me, that odd but pretty photo makes it look like little clusters of eggs on the leaves, rather than damage.

I thought it might be a job by skeletonizer but don't they only eat grape leaves?

==>> not that i am aware of ... ive seen it on a lot of stuff.. over the years .... and the term is a bit off.. i have seen leaf miners do it to columbine ... many such bugs might be plant specific.. but i wouldnt go as far as making presumptions limiting their swath ....

https://duckduckgo.com/?t=ffcm&q=leaf+miners&iax=images&ia=images

but i dont think i see that here .. on this pic ...

does any damage show on the other side???

who knew.. and go figure... lol

https://duckduckgo.com/?q=skeletonizers+on+grape+leaf&t=ffcm&iax=images&ia=images

ken

White residue could be just from the soapy water that I applied.

Here are day time photo

Whatever it is, the damage is slight and old. I honestly don’t think it’s worth worrying about, unless the whole tree is affected, and I wouldn't do anything about it. We still don’t know the tree species or location.

Michelia Alba in southern CA.

Damages are new though. I check on the tree daily. Sadly never catch the bugs in action....