What in the world is going on here? Pic included
I've been scouring the internet, with no luck, to try and find out exactly what is going on with my NOL. About a month ago, the leaves started cupping under. Now it looks as though they want to fold in half all together. I've had trouble with spider mites with a brug in the back, but it's leaves are all gnarled and distorted. This one, I've kept the under side of the leaves washed off and I even sunk to the point of using a systemic on plants that the bees don't touch. I can go over this with a magnifying glass and not find any mites, so I really just have no idea what is happening. I'm eternally grateful for any suggestions that you guys can offer.