There is a real problem with Bark Beetles in the mountains. I have long thought the wasps, yellow jackets carried them, beetles, away and laid eggs on them. A few years back the there was a move to eliminate yellow jackets, they were bothering people because of their great numbers. Bate, traps and spraying cut down their numbers, I haven't seen one for a long while and I believe the bird population suffered too. I think that the increase in the Beetle damage is a result here in the mountains.