Powder post beetles....

[Bill Ragosta]

 

  OK, so I had a couple of trees milled recently.  There was a Chestnut oak and a cherry for assorted furniture projects, and a large American chestnut just because it was dying from the blight and I didn't want it to rot in the woods.  Anyway, I picked up the lumber from the sawyer today and it looks great, but he pointed out a couple of boards of the Chestnut that had what appears to be damage from Powder post beetles.  I'm fine with some "wormy Chestnut", but I don't want to look in a few weeks and see that the wood is absolutely overrun with the critters. 

I didn't have a long discussion with him about it, and not being a sawyer or kiln owner myself, I don't really know what the prescribed method is.  He did suggest that he had it over 120 degrees for two weeks and I think it was in the kiln for 4 weeks or so total, but I don't think he ever had it at very high temperatures.  Do you suppose I'm safe and that the 120 degree, dry air for 2 weeks would have killed the buggers, or do I still need to heat/treat or spray the wood now to control them?

Thanks in advance for any education you all can provide.

Here's a photo of the Chestnut with a few of the worm holes.....

[PC-Urban-Sawyer]

I think you need more heat... I believe it takes 140° F internal temperature for at least 24 hours to kill ppb eggs, larve and adults.

Herb

[Bill Ragosta]

I think you need more heat... I believe it takes 140° F internal temperature for at least 24 hours to kill ppb eggs, larve and adults.

Herb

Thanks Herb, given that I've already taken it home and don't really want to argue with my guy about how he should have handled it, is there something that I can spray on the boards to insure that the beetles are goners?  Or should I just watch and see if I can see new evidence of an infestation?

[Glenn1]

PC Urban Sawyer is correct about you needing more heat.  The internal temperature in the center of the board needs to be at least 135 degrees for 18 hours to be on the safe side. 

[btulloh]

Timbor or Boracare

[GeneWengert-WoodDoc]

These are probably anobiid beetles (ambrosia beetles) and so they do not infest dry wood.  Have you seen any activity (powder coming out of holes and new holes)? 

You do need heat to kill the lyctid PPB.  In fact, any insect is killed at 133 F throughout the wood.  To get this hot, you need air temperature around 150F.
Note that this temperature kills all insects and their eggs.  You do not need more than 30 minutes at 133 F.

Note that a chemical treatment (Timbor or Boracare) is not possible for kiln dried wood as the chemicals are in water, so you have to redry the wood.  To get the chemical deep into the wood, it takes several Days of soaking the wood to have the required penetration.

[Bill Ragosta]

I just picked up the wood yesterday and haven't seen any activity since, but obviously I'll be watching it now to see what's going on.  Thanks for all of the information, it is educational for me as this is all new to me. 

[WDH]

Are the holes free and clear of any frass (chewed up and excreted sawdust)?  Do the walls of the tunnels have a black discoloration?  Or, are the holes packed with frass?  They look in the pic to be open.

[Bill Ragosta]

Are the holes free and clear of any frass (chewed up and excreted sawdust)?  Do the walls of the tunnels have a black discoloration?  Or, are the holes packed with frass?  They look in the pic to be open.

Yeah, I think that they're open.  I brushed whatever sawdust was laying around or in the holes this morning so that I could gauge if there's any new activity.  I presume by your response that if they're open that there's no current activity and the beetles are likely dead?

[GeneWengert-WoodDoc]

On the left side of the picture, you can see where the holes have been cut lengthwise, which means they were in existence prior to sawing the lumber.  So, these were in the log prior to sawing and active prior to sawing.  The powderpost beetle that we fear, the lyctid PPB, does not like wetter wood, so these are indeed nothing to worry about; these holes came in the log.

[Bill Ragosta]

On the left side of the picture, you can see where the holes have been cut lengthwise, which means they were in existence prior to sawing the lumber.  So, these were in the log prior to sawing and active prior to sawing.  The powderpost beetle that we fear, the lyctid PPB, does not like wetter wood, so these are indeed nothing to worry about; these holes came in the log.

Excellent and great info.  Thank you.

[WDH]

I presume by your response that if they're open that there's no current activity and the beetles are likely dead?

No.  The holes made by ambrosia beetles are open.  PPB holes are filled with frass.  The fact that they are open confirms that they are most likely ambrosia beetles.  Once the wood begins drying out, they leave and are not an issue.  Aside from the holes they make in the wood, they are nothing to worry about.  The PPB's, on the other hand, are the ones to worry about.

[Sassafras73]

I agree about ambrosia beetle. They are quite abundant here in Ohio following the emerald ash borer around.  From what I have read and observed they have a sweet spot for the moisture content of the wood and this is why they don't invade healthy trees.  Once that moisture content drops they invade but once too dry it's no longer suitable.  They don't feed on the wood but rather introduce a fungus which they feed on, hence the black stains. Standing dead and heavily declined ash in our area are full of them.  They can jump into cut logs during the growing season.  If they were active in lumber that wasn't dry enough you might see straws of frass (stuck together sawdust) coming out of the exit holes. I think WDH is right in the assessment.