We have a lovely maple tree on our property which had one of its upper main trunks die off. I removed the dead upper portion of the trunk a few years ago and the tree has remained healthy looking and has leafed out fully every year since. My concern is what appears to be bug holes approximately 8 feet up from the ground (see photos attached). They have been there prior to the removal of the dead upper trunk I but wanted to know if I should be concerned; and if there is anything I could do to ensure the tree remains healthy. Appreciate any assistance you can offer.