Signs of Powder Post Beetles -- HELP!

[David Wadstrup]

Hi,

I've been on a few hunts for lumber in the past month, and have collected about 250 bf of both air and kiln dried walnut and 75 bf of air dried sassafras. On one of these hunts, I also picked up a very nice 6' x 20" slab of kiln dried myrtle. Just yesterday, I rearranged my wood pile(which happens to be in my shop, which happens to be in my living room) for easy access to the pieces I'll need first. Like usual, I topped the pile off with the wide slab of myrtle. Just this morning, I noticed fine dust and an insect exit hole in the slab of myrtle. And upon closer inspection, I noticed about two dozen more exit holes. The holes are small, 1/16" in diameter or smaller, and are pretty round. From what I can gather these were made by exiting powder post beetles(?) Of course, I'm panicking. Not only am I watching the $200 slab of myrtle being cosmetically ruined before my very eyes, I'm afraid that these exiting insects may infect the over $2,000 worth of walnut and sassafras sitting underneath it. Does anyone have any advice on how I can keep this from happening? Is it possible that this will happen? Has the damage already been done?

So far, I've only removed the infected piece of myrtle from the pile. I've read that treating lumber with boric acid can help ward off infestation. Unfortunately, I need to go a non-pesticide route. As I mentioned, my wood shop is in the living room of my one bedroom apartment(I am a hand tool woodworker), and I can't risk putting toxic substances(even ones with mild toxicity like boric acid) in our(my wife, my cat, myself) living environment.

I've also read that heating the lumber to 130 degrees for a few hours will kill all eggs, larvae, and adults. Should I try to do this? I cant imagine how I will, but it will be worth a try for such valuable wood if you feel it will help. A thick tarp sealed around the pile with some sort of heater pumping air into it, maybe? Or am I just being paranoid? Is the likelihood of a handful of insects infecting this wood slim? Am I worrying about nothing?

Please help!

[Mel Fulks]

In summer a day or two in a car parked in the sun would do it,I'm farther south but my car interior can go to 160 f. Cold works too,I'm sure you can find proper temp on line.

[Mark Bolton]

It will take a long time to heat the core of te material to the temperatures and duration needed. The heat option is not a simple process. You can read a substantial amount on heat treating for bugs in the archives at woodweb.

The borate treatment can help to protect any wood not currently infested. If it were me, and I were in your situation, Id first make absolutely sure what the infestation is, then guess I'd be looking for a kiln to haul the material to.

Your wife must be one amazing woman. You'd better do all you can to keep her around ;-)

[Mark Bolton]

In summer a day or two in a car parked in the sun would do it,I'm farther south but my car interior can go to 160 f. Cold works too,I'm sure you can find proper temp on line.

I don't know if your joking or not but this would never work. You would have to be able to get the core of the material to temp in a single daylight cycle because you would retain zero heat (even if you rant the car with the heater overnight ;-) ). Multiple days would be zero gain.

Sure does get hot in there though. My ex-wife use to dry herbs in an old truck of ours but never thought of heat treating lumber..

[Jim Andrew]

I found I had PPB in a couple walnut boards, and rather than cut them up and burn them I put them in a empty metal grain bin. When I checked them a few months later they were clean of PPB. So a metal building does get hot enough to kill PPB.

[Mel Fulks]

Wasn't joking ,but could wrong . It's been a while since I researched this and I do remember opinions on temperature and duration varied. He might yet have enough cold weather left to do the job or access to a freezer. I'm sure you are right about heat retention . Car could still be used for part of required time. I have noticed that there are sometimes warnings about leaving a child in car because "temperature can reach 120". That is way off.

[phil harold]

i know you can use diatomaceous earth (not a pesticide) to prevent infestation

once you have an infestation heat works some time you may not notice for a couple years that you have the bugs

[Tad Capar]

I had this problem once and tried to freeze them out as been suggested, but it did not work. It might work in cold country, but here in Norheast it just is not cold enough. I stocked these boards individually with sticks, kept them outside for weeks with night temps in teens, but did not work. Come Spring, with the temperature in '70s (I think), stocked them up on couple pallets with sticks and space between boards. Placed several shallow plastic dishes filled with ammonia inside the stockpile and covered it tightly with a 6 mill poly (placed the plastic on top of pallets before stocking boards) sealing all overlaps with tape (creating one big plastic bag). Even though it was suggested to use 18% ammonia, I took a chance and used the supermarket type. I kept it like that for a couple of sunny days and it worked. It is still chilly here in Northeast, but Spring is around the corner.

[David Wadstrup]

Hi Tad. I hadn't heard about the ammonia. Are the fumes supposed to kill the beetles? I imagine it would only kill adults that have already surfaced.Or is it effective on the larvae and eggs as well.


What is the consensus? Is there a way to protect the uninfected lumber at this point? It's all rough cut, and I'm not able to finish it yet. Or do you feel that I might be overreacting?

[Paul M Miller]

Cold doesn't work. If it did, we wouldn't have powder post beetles here in Michigan. We have the occasional 15 or 20 degrees below here and the beetles thrive. No help to you now, but I dip green boards right off the mill in a Tim-Bor solution before air drying.

[Mel Fulks]

Paul ,that's interesting .At least one of the sites I looked at said it did and gave a temperature and needed time. I'm beginning to think some Internet info is not accurate.

[Ronald Blue]

I don't know if you can get enough heat in a car but a solar kiln works well for drying wood without danger of heat treating or tempering it. It seems to generate enough heat to kill bugs and larvae.

[Scott T Smith]

David, I'm a kiln operator. The only recommended method for killing PPB larvae, etc is by heat. You want the core of your lumber to reach 133F or greater for at least 30 minutes. Typically I'll set my kiln at at least 140F overnight to be sure that things get warm enough.

You can easily do this at home by building a sterilization chamber out of foam board and using a space heater. FWW magazine had an article about this in the back of their mag a couple of years ago; I think that it was the December '11 issue (or one that arrived that month). Somewhere I have a copy of the article; send me an e-mail if you'd like to have it.