We have a beautiful Deodar in our yard. A few months ago, I noticed several branches appeared to be dying -- needles browning and dropping off. On closer inspection, I noticed many holes in the bark of the tree -- both at the base of the trunk and even on some higher main limbs. The holes each seem to be about a centimeter or so in diameter, and be clustered in groups of 5-6 holes running next to each other horizontally (pattern parallel to ground) across the tree. There have to be at least 15 groups of these hole clusters that I saw. Some appear new (fresh sap oozing), and some older (dry sap "plugs" in the holes). Any idea what these may be and what I can do about them? Your help is greatly appreciated.

--Marc