We have a maple tree that we planted 2 years ago. It has been the picture of health since we planted it. It was hit hard over the last few weeks with Winter Moth caterpillars, and as we were examining it a few days ago, a 3 foot section of branch that we had pulled down snapped off. The pith was black inside around the end of the branch and the area above had small vertical cuts in the bark. All appeared fine about 3 inches up from there and the leaves were healthy. Upon further examination of the tree, we found another area with the same symptoms (see attached picture). Is this a disease? Should we not cut this branch off or call in a tree specialist? I'd hate to cut off anything unnecessarily since the caterpillers did a number on the tree over the last week or two. Thanks for your help!