I'm 80% sure that it's the four-liners. Their MO is to suck the chlorophyll out of the leafs in perfect little circles like that. In a couple/few days the spots will turn brown or transparent, then leave a hole. Be sure to look on the undersides of the leaves. If no more damage is done, there's nothing to worry about. But, they can be prolific little bastages, moving on to other plants. Neem oil (available almost everywhere, including Lowes) works well on them, but you may need to spray every few days till they are under control.