The leaf damage in your photo appears to be caused by chewing and is likely from a caterpillar. Whether to treat or not is dependent on how much of the tree is impacted. If it is just a few leaves it cosmetic and likely does not require treatment. Treatment options require knowing what is causing the damage. I would recommend checking the tree daily, look for insects, caterpillars, webbing. If found place in a plastic bag and bring to a local garden center for identification/