Moved from Unidentified Leaf Mines.

Okay, seeing the leaf in person, its clear that it's P. vitegenella--a very superficial, "snail trail"-like mine. It's not always easy to see that in photos due to variable light conditions. The larva has now pupated in a little fold on the leaf margin, as is characteristic of this species (P. vitifoliella typically pupates away from the leaf margin.). I've never noticed a visible frass line in vitegenella before, so this is good to see--and I'm happy to have material of both species from a new location to include in the DNA analysis. Thanks again for sending the leaves!

Yes, on grape. This mine is a little strange--it seems to be P. vitegenella, but there isn't normally a visible frass line in that species. The other option would be P. vitifoliella, which makes deeper mines with a much wider frass line. This is reminiscent of mines that otherwise have only been found in the southwestern US. I'm about to get some DNA analysis done on Vitaceae-feeding Phyllocnistis, and I'd love to include material from mines like this one if you're able to find more and collect them.