Safe Treating to Prevent Powderpost Beetles

Borates are a practical alternative. Heavier-duty chemicals have drawbacks. December 8, 2012

I poured a pad of concrete behind my shop with the intention of air drying lumber. I live in 50 acres of woods with 47 mature white oaks on my two acres. I have a massive powder post beetle infestation. They have not bothered my indoor wood or home, but my firewood pile is riddled with holes and frass is everywhere. Is there a way to pre-treat wood to be air-dried so powder post beetles will stay away from it? The question is not killing a current infestation, but rather keeping them out in the first place. My sawyer suggested linseed oil. I can do that and just use solvent based finish and nitro lacquer. Will that work or is there a better product?

Forum Responses
(Sawing and Drying Forum)
From Professor Gene Wengert, forum technical advisor:
You want a chemical to put on green wood that will prevent insect infestation. There are chemicals sold for that purpose with the lumber dipped in the chemical, but the chemicals have a short useful life. If they had a long life or more than a few months, that would be treating wood and you need a license. Also, anyone using the wood or products made from the wood could be damaged by the chemical. Check a lumbering magazine for names of companies that supply chemicals. Of course you do not want to spend too much money either.

From contributor M:
Would netting work?

From contributor D:
I believe the current recommendation is to use either Timbor or BoraCare. One of these chemicals is for using on fresh green wood, Timbor(?), and the other for dried wood - research to find out more. To my knowledge, neither chemical requires a license to purchase.

From Professor Gene Wengert, forum technical advisor:
Borates are not suggested for green wood, as the chemicals are in a water-based solution, so the mixture cannot adhere to or penetrate green wood well enough to give the desired protection during air drying. It will also wash off in rain. Use borates for partly dried wood.

The PPB does not like green wood, so insects flying around lumber when sawing, or soon after, are not the lyctid PPB. In fact, they are likely not even wood boring insects, so they are not serious pests for lumber. The PPB likes wood under 45% MC down to about 8% MC.

From contributor J:
Contributor M asked if netting would work. I was going to ask the same question. How big are PPBs? Would they fit through screening?

From Professor Gene Wengert, forum technical advisor:
The lyctid PPB insects are very small. The exit holes when they leave wood are 1/16" to 1/32" diameter. Note that some wood, such as Douglas fir, is quite dry when freshly cut, so borates could be used. Hardwoods are mostly 75% MC or wetter.