It's a little hard to tell from the picture, but is the surface of the leaf gouged out? That suggests something that chews, like a beetle, caterpillar or slug/snail. What are the pellets that you've already applied?
That's happened to me with fertilizer, when I wasn't has careful as I should have been. I have seen granular slug pellets that look like that, too. Either way, I don't think you want them way down your leaves like that.
I think the question is whether the pellets were put down before or after the problem appeared. If it was before then they could be related to the problem, but if they were put down after (perhaps a pesticide in an effort to fix the problem) then they are not the cause (although as has been said, it is not a good idea to have them in the crown depending what they are).
