I think I have some kind of bark beetle. Well, not me personally, but the pine tree in back. Its foliage has been yellowing for a few years now, though it gets new growth every year. Then last week I noticed these holes. They could be from insects, or just from woodpeckers or sapsuckers (who would be going after...umm...insects. Shoot.) It will be sad if we lose this one, planted as it was from a wee sapling some thirty-odd years ago by either my brother or my sis. (Two were planted, one survived, we're not sure which.) The holes aren't random, they're kind of in a straight line, ringed around the trunk. A couple of hapless ants are immortalized in the sap droplets. Apart from the holes, I don't see any tunneling along the inner layers, under the bark (which has always, to my memory, peeled a lot, so that might be normal. I don't know what kind of tree it is exactly.) So, I'm hoping it's birds, as maybe that would mean the grubs are gone and the tree can recover. It's putting out new growth at the tips as usual, so for now I will fight the invaders with organic weapons like insults and regular watering.