Originally posted by Mike Maas
Do carpenterworms need wood decay for habitat? I understand they like stressed trees, but thought they bore into solid wood.
They do, but first they have to get there. I've been watching the moths lay eggs on infected sites these last few weeks I've been treating oak ooze disease. they lay their eggs in bark crevices:
"carpenterworms, Prionoxystus sp., are also active in these infection sites. As Johnson and Lyons report in Insects that Feed on Trees and Shrubs, “Over a period of time the activities of the carpenterworm larvae may prove disastrous to the host tree…” The need to expose and treat this pest calls for the removal of dead bark. Bacterial activity and slime flux on older oaks can and does kill cambium, expanding the diseased area every year. So there is also a clear need for noninvasive methods to preserve the tree.
Carpenterworm larvae were actively feeding under the bark at the two largest white oak infections, 13 and 16 inches wide. Larvae were not found in smaller infections, perhaps due to a sinister symbiosis between these two problems. The adult moth lays its eggs in the same time period that the slime is flowing. They are also known to generally prefer ovipositing in bark crevices, but the larvae can enter infected bark much more easily than healthy bark. They expand the infection as they feed, which attracts more adult moths to lay their eggs there, and around and around the cycle of destruction goes."
Mike I'm all for excavating shallow cavities, but like you I'm leery about digging too much into deep ones.
"What if you have a strong CODIT wall and you put a really large amount of fungus on it, will that make it more likely to fail than just having the normal omnipresent amount of fungus?
I would say yes. If any of those fungi are active enough might they not break the wall? If there's a lot of rot active, it sends out enzymes that can soften and break a wall. How do you know the wall is strong enough?
When I do reduction pruning, I do not whack every branch back. When I excavate cavities, I get real cautious when the wood resists probing. I stop when I hit even decaying wood if it's giving needed structural support. I think we're pretty close on these issues.