Recently, I was asked by a coworker to look at a spruce tree in his front yard. It was a beautiful, stately specimen that was as old as his house. There were a couple of dead limbs with dead needles here and there, but nothing real obvious. My co worker told my his neighbors tree looked like this a year ago, and they died just all of a sudden.
When we went to look at the neighbor’s tree they had several spruce trees, in all stages of infestation. Peeling off some bark revealed what you see above – spruce beetle excavations and frass. Holding the bark to the light you can see holes where beetles have either entered to lay eggs or exited when mature. My coworker can try treating his tree in an attempt to save with insecticides, I looked for recommendations online and this is a professional job. Every spring a fresh crop of beetles emerges to have a fresh go at his tree from the neighbors. There are a lot of old spruce trees in this town and an urban forestry program that treated these beetles on a landscape scale would have as much luck as the National Forest Service is having with Mountain Pine Beetle. People aren’t used to being told nature wins, but in this instance regardless of what my coworker does the spruce will probably die.