Question
I have a medium sized Japenese Maple (about 5 inches in diameter at the base of the trunk, and about 15 feet tall).  Last Fall, I noticed that there were some places on the main top branch where the bark was slightly distended.  When I peeled it back (most of it flaked right off), the wood was powdery, and it could be brushed right off.  It looked as though the tree had healed itself around the affected areas, beacause it was scarred off around those places.  However, the bark did not regrow over the areas, and now I have noticed single holes in each of the areas (probably about five different affected areas up the branch)  I know that Japanese Maples are very sensitive to any pesticides, but I suspect a bore (I lost a cherry in close proximity to the same problem).  It is a beautiful tree, and is otherwise healthy, and it looks to be in the early stage of infestation, so I would like to know if there is ANYTHING I can do to rid the tree of the bores, without killing it alltogether.  Hopefully there is something that can be applied at the base to be absorbed internally into the tree.  Also, what can I do to protect the areas that are now exposed (no bark)?

Any suggestions?  Thanks!

Answer
I would check with your local Nursery/ garden type store and ask for an insecticide for borers on maple. The nurseryman(woman) can give you some advice on IDing the borer and its control. The one I normally recommend is Onyx but it is sometimes hard to find. Here is the label with instructions for Onyx http://www.srs.fs.usda.gov/4501/onyx%20label.pdf