Hi! I'm fairly new to gardening, and recently bought a couple of 4 foot tall Ilex Crenata "Sky Pencil" holly bushes for my little garden. When I bought them, I did notice a couple of leaves had markings/holes on them, but wasn't savvy enough to realize they were early signs of what could be a big a pest problem. Now that I've had the plants in my own garden for a couple of weeks, I've discovered that there are more leaves that look like they've been chewed right through. It almost seems like whitish "blight marks" appear, and then these actually get eaten/burned right through the leaf. On top of that, a few non-chewed leaves are dropping off. Yet there's a ton of new growth on both bushes.
I have yet to see any kind of critter, so I'm wondering if any of you can tell me what I might be dealing with by viewing the attached photo of some sample leaf damage. I bought a bottle of Neem oil today as the guy at Lowe's said it would safely act as both an insecticide and fungicide. And I don't see anything about not using it on holly bushes, so I'm assuming it's okay. Any ideas as to what pest(s) I'm dealing with here? Is Neem oil the appropriate treatment? Your help would be greatly appreciated -- these are absolutely beautiful bushes (and they weren't cheap at this size!) so I want to make them well asap. Especially if there's a chance the critters in question might spread to other items in my garden (though it's mostly heaths/heathers near these hollies). These bushes may also be tricky to treat thoroughly with any spray, as the branches all grow so closely together. Thanks for any identification/guidance you can offer!
