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Killing PPB by freezing

Started by jpm717, February 05, 2019, 02:01:17 PM

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jpm717

I wrapped some boards with plastic wrap and put them in my freezer for 3 weeks  + and that seemed to kill the ppb. So far no sign of sawdust from the holes. Has anyone else try this?

Jerry

GeneWengert-WoodDoc

I believe that this is not true if you are talking about the lyctid PPB that infects dry hardwoods, as the freezer has to be close to -40 degrees.  You need to kill both insects (larva) and eggs.  When the eggs hatch, a larva (looks like a small worm) tunnels into the wood.  It can be 2 years until they emerge from the wood.  They emerge most often when it gets warm after cold weather.  They are not active in cold weather or when they first warm up.  We do not know exactly what triggers their response to go from larva form to insect with wings and as an insect for them to tunnel to the surface and emerge in order to mate.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

moodnacreek

How about dead packing infested boards for a year or so they can't get out and start over?

tule peak timber

Dr Gene is correct.We have had to kiln previously frozen woods from another vendor to kill ppb.Passing ppb can ruin a businesses reputation !
persistence personified - never let up , never let down

Larry

Wood turners use a lot of junk wood loaded with bugs.  Several of us have been putting the turnings in the microwave with what seems like good results. No fresh fras has been observed after the nuking.
Larry, making useful and beautiful things out of the most environmental friendly material on the planet.

We need to insure our customers understand the importance of our craft.

GeneWengert-WoodDoc

The lyctid PPB, that infects dry and mostly dry hardwoods and bamboo, is killed by heating to 133 F.  Such heating can easily be achieved in a microwave for small pieces.

Unfortunately, the ultimate test of any new or different treatment requires waiting two years to see if the insects leave the wood; that is, there is no way to determine if the lyctid PPB is still active unless we see exit holes, which may not develop until two years after the initial infection.  Usually, exiting does not occur until the wood is around 70 to 100 F. 

 The insects are inactive when the wood is cooled to under about 50 F, but cooling does not kill them.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

tule peak timber

For us that trigger is the warm fall weather condition call a "Santa Ana ". Wood assumed safe from insects suddenly comes alive after long periods of storage.Besides cleanliness , good kiln practices, I'm now going to use more preventive chemicals after milling -especially for certain high risk materials (ash , walnut , myrtle, etc). I've learned  the hard way >:(
persistence personified - never let up , never let down

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