There are several types of PPBs, some go for different wood. Some types will go for dry wood, others not. The larvae bore deep into the wood eating as they go. There is a lot of info on the web about what to look for and how to protect from infestation. A sure sign of active infestation is fine wood powder, frass, dropping from the holes. The females lay eggs in pores and crevices in the wood, the eggs hatch and the larvae start boring and eating. They may stay in a chunk of wood for years before they come out as adults and fly away. There has been much written on this and other forum about what to look for and what to do. You might try a search here and on the wood web.
This recent thread had some comments:
While turning some spatled maple I noticed powdered post beetle holes on the bowl exterior on one side only. Figuring the critters would not have a resistance to HSS I finished the bowl down to about a 1/8 wall thickness. The bowl is now in a plastic bag while I debate what to do with it. The holes are about even in number inside and outside but hard to count.
All the advice I’ve seen is on sterilizing blanks not a bowl with a fraction of the overall size. So far I’ve microwaved the bowl for two minutes and put it on the dash of the car in the sun, where temps got into the 110° for a...
Here's an article on PPBs.
en.wikipedia.org
Something on the life cycle:
Powderpost beetles destroy wood in buildings. This bulletin will help you to identify infestations and how to control these pests.
extension.entm.purdue.edu
If cutting logs you can protect from PPBs by applying products like Boracare.
If there is no active beetle infestation, the wood is fine to turn. The trick is knowing when to turn and when to panic.
There are other types of beetles, for example Ambrosia maple typically has beautiful fungal discoloration with two or three beetle holes close in a row across the discoloration. Here are some blanks I cut from some BIG ambrosia log sections: about 30" dia, 16" length.. Hard to see beetle holes in these. (Ambrosia beetles are different beetles than powder post beetles.)
Wormy chestnut can be beautiful. I think the holes were also caused by ambrosia beetles. I take all the wormy chestnut I can find.
The fungus could be the start of spalting, but you won't see any spalted wood for a while, maybe months, as the fungus moves through the wood eating what I can. BTW, the black lines you see in spalted wood are not the spalting itself but the protective zone lines the fungus create to protect their claims. If you keep the wood damp the fungus can work it's way through the wood and cause spalting. But there's a fine line between spalting and rot.
JKJ
