Question
Hi Jim, I have two beautiful Red Maples shading my deck.  One of them has dark holes in the trunk, various places.  It looks like it could be insects.  They look deep.  I only saw one in the spring, now there are more.  I saw that someone in one of your other questions dug into the hole and found a worm.  Should I do this, to see if there is something there, or should I assume I have a pest and treat it.  The other Red Maple has nothing.  Please help, these are very large trees, and they are a pair, I would hate to lose one?  What should I do and could I lose the tree?  I happen to have a Dogwood not to far away from this tree that had a tree bore problem could it have spread to my Red Maple?  I treated the Dogwood, but have not treated any other trees in my yard.

Answer
Sounds like borer damage. Usually a specific borers will only infest certain trees. Dogwood borers infest dogwoods and other hardwood trees but not usually maple, and there is a maple borer that infests maple. There are others that will attack most hardwood trees. I would cut the loose bark from around the wound and spray the area with an insecticide called Merit or if you can find it Onyx. Do not put wound dressing on the wound since this will slow the healing process. Both are new insecticides that will work on borers. Some borers are under the bark others are in the wood. The ones in the wood are more difficult to control since the insecticide may not penetrate the wood. If there is a boring hole spray the insecticide into the hole. Wait a couple of days and check for new boring dust and if you see new dust or wood shavings re spray.