I’ve read up pretty extensively. To include the ag extension agent’s literature.
Here’s the deal as far as I can tell.
-They are slow. Usually not a crises.
-There are a lot of species of wood destroying beetles. Some tougher than others. No hard and fast rules on how they operate.
-They can lay dormant for 1-20 years. Jeeze.
-Removal is best option (not an option here)
-Timbor and Boracare work. Essentially borate salts. Boracare is borate and old fashioned ethylene glycol. It soaks in deeper/better.
-They eat it on the way in or on they way out and die. But if you miss a spot, they don’t eat it.
-They don’t like to go through paint or varnish on the way in. But they can use old exit holes.
-Starch declines as wood ages and they won’t lay if starch isn’t high enough.
-They don’t do well with low moisture content in wood. Therefore air conditioned space helps.
-Fumigation is wildly expensive and the good chemical that kills them is no longer available.
-Heat kills them. 125-140 eff. This may be an option. I could get a big propane heater in there on a day when the ambient is 110 and bring it on up for 12 hours. Not sure if this is going to be kind to the structure or windows.
I’m soaking the place in about 10 gallons of Boracare. The plywood, timberstrand, pine, and advantech soak it up.
The LVL is varnished in some way and it beads. This may be an issue because I have some beetle holes in the LVL (photo below). In theory, they don’t like the glue lines. But in theory, they shouldn’t have gone into the LVL in the first place. So they may have gone in and died. Or they could be having a party. Not sure what to do about this. Lots of structural LVL.
Later, when my solar setup is complete, I can air condition/dehumidify the place full time. That could/should help.
Overall, a real pain in the rear. I saw the one punky piece of wood where I got them originally. Just a scrap piece of blocking. I treated it. And saw no activity for 2-3 years. They there was dust and more holes. So they were back.
The piece in the photo above was a cut off from a stair stringer. It was added later and the cutoff sat on a wire shelf for a couple of years. It may be a different beetle. Or the same batch.
I’ve only recently added garage doors to the place. That should help with the moisture content of the wood.
Thanks all.

