Preview of coming attractions? See
http://www.nytimes.com/2009/07/02/garden/02tree.html?_r=1
Yesterday, I was sitting on the deck when an Ips or Pine Beetle landed right in front of me. I crushed it before I could inspect which of the two species it was.
What is fascinating to me is that the Ips beetle has infected exactly 2 trees of out of hundreds in my yard. The first tree was about a foot in diameter and broke in half during the big snow storm in the spring. Hundreds of Ips burrowed into the entire length of the fallen tree. The second tree was about 6 inches in diameter. I had cut it shortly after the storm
I've been carefully inspecting and monitoring the beetle kill up here on Winiger Ridge. I now understand WHY the beetles prefer larger trees. It's because the bark is thicker. The thicker bark protects the beetles from the woodpeckers. The woodpeckers can easily remove and dig through the bark of a 4 inch pine. However, the cost/benefit ratio tilts in favor of the beetle and away from the woodpecker for larger trees with thicker bark.
In other words, the calories bound up in the tiny beetles are too small to feed a woodpecker if the bark is too thick. (Thicker bark requires more calories to burrow through.)
Let me get back to the two fallen trees that became Ips beetle magnets. Clearly, the beetle could sense that these trees were helpless. Every beetle from hundreds of yards around came to these select trees. It would seem to me that one could design an Ips beetle trap by simulating a fallen tree. Once the Ips beetles are trapped, they can be managed.
The two infected trees are now under wrap. Pray for a serious cold snap this winter. I'll be OK with the cold; by then the plastic wrapped trees will be firewood for the wood stove.
