Trees, Shrubs and Conifers: Sick or Dying Lilac?, 1 by Shaigirl

Shaigirl wrote:
I'm worried about our lilac. I'm not sure specifically what it is or how old it is. I just know that it looked great up until summer. About that same time, the horrific plague of 13 year cicadas was at its peak and I just figured that had something to do with it. Now I'm not so sure. It looks pretty rough. There are parts where it looks like the dead of winter. Most of the bottom has no leaves and all of the mid-section leaves have nasty brown spots. Today, I discovered some sort of beetle gathering on the bark in the middle. What's going on here? After taking some pictures, I knocked off the beetles. It appears the wood beneath them is damaged. IS there anything I can do to save it? Should I spray something and/or cut out the infested areas? HELP!!!