Thank you for your question and photos. The holes that you're seeing on your maple sapling leaves are typical of those made by leaf-cutter bees. These valuable native pollinators play an important role in our ecosystem and are nonaggressive toward humans (they'll only sting if handled, and even then, their sting is very mild). Any damage they do to plants is typically minimal and would not harm your tree, so there is nothing you need to do. Here is a link with more information about leaf-cutter bees.

https://marylandgrows.umd.edu/2022/05/09/bees-to-look-out-for-leaf-cutter-bees/

I hope this is helpful.

~ Karin

Thank you very much for your prompt and helpful response.

You're very welcome!