Oh, there are many leaf eatin' insects that produce holes ranging from "shot with buckshot" appearance to round holes, scalloped holes and even sorta square notched holes. I'm thinking flea beetle and since they eat and hop away, spraying is silly since they aren't there. Don't discount grasshoppers, etc. Diseases, you'd see damaged leaves, not just holes. The fungal problems take awhile to produce a true hole. I would not consider any chemical until I knew what was the culprit, what was total expected damage (simple cosmetic does not endanger the shrub) and what point in the life cycle you needed to apply. By the time you figure this out, the bug has probably moved on. What about wind damage. Here blowing sand can sand blast leaves.