The damage could be caused by a type of small beetle or a particular disease that make "shot holes" in the foliage. I doubt that the damage is bad enough to warrant spraying. The best thing you can do is take some foliage showing the damage to your County Extension Office for them to look at and diagnose more completely. Then if a spray is needed they can direct you to the best ingredients to look for when you visit your Home Depot Garden Center.
Q&A Library Searching Tips