lumber w/ powder post beetles

[240b]

I've got some maple lumber with what I think are powder post beetles in it. Is it junk or is there a way to kill them? I'd rather throw away the wood than infect the house.  Its a few hundred feet of birdseye. was going to make a table from it.

[terrifictimbersllc]

My understanding is that these beetles won't infect your house.  The lumber in an average heated/air conditioned house is too dry for them to live in, and besides that they don't like softwoods.

Regarding killing them and their eggs, I've read heating them in a chamber for 160 degrees F for 3 hours, or 140 degrees for 24 hours, will do it.   How to achieve such a chamber I'll let others weigh in.  One needs air circulation inside in addition to heat, otherwise the top is hot but the bottom is cold.

[JustinW_NZ]

yeah as above, kiln dry the timber will kill them off.

Cheers
Justin

[Tree Feller]

Take the lumber to a kiln and have it sterilized. Last I read, 132 degrees for 4 hours would sterilize 4/4 lumber but Doc Wengert said he thought that was currently being changed. In any event, overnight in a kiln at 140 degrees or higher should do it.

[Ironwood]

The "Galleries" are perpendicular to the surface, so you wont plane it very far before the little 1/32" holes become LOOOONG multiple holes and not so nice. IF you can leave the top surface intact and sand it lightly, enjoy the saw marks and the grain, otherwise the riddled surfaced beneath will obscure the grain anyhow.

Yes to sterilize. The holes you see at the surface are actually exit holes, emmergant adults have laid eggs, exited and died. The eggs are now in the frass filled holes beneath waiting to hatch next spring and start the cycle again.

I have done alot of inquiring about wood bugs, including Carnegie Mellon Entimology and online. The standards given by nearly everyone was from research done in England in the 1940's and based upon only one type of bug. I tend to overdue the heat at 180......just me...




Ironwood

[Brad_S.]

I "over cook" too just to be sure as well.
I have a woodworker who will buy all the sterilized ppb lumber I send his way...the more infected, the better. As mentioned, the holes turn into meandering lines once planed but he uses that look to effect in his creations.

[GeneWengert-WoodDoc]

The lumber must be 133 F throughout and so this takes about 160 F air temperature.  You can infect other hardwoods in your house.  Also, while  waiting for them to hatch, they will do a lot of damage inside the wood.

On the other hand, they prefer grainy hardwoods, so it is rare to see them in maple.  Perhaps you have ambrosia instead.

[WDH]

I have had them in red oak, white oak, pecan, walnut sapwood, and persimmon, but never maple or sycamore.

(What a nightmare  ).

[samandothers]

I have some old dry oak boards that have been in an old house that contain small holes in them. When I cut the boards or plane the holes then turn and run horizontal.  My question is once infested do the beetles (and their off spring) ever leave the wood or continue to infest until it is swiss cheese?

[Ianab]

My question is once infested do the beetles (and their off spring) ever leave the wood

The grubs that are making the holes eventually mature and leave the wood to find a mate, then lay more eggs, either on the same wood, or a better tasting piece nearby. So spraying it with a borate based solution can work. It either kills the bugs, or persuades them to go elsewhere. Either way the cycle is disrupted.

Also cooking them in a kiln gets them all. I've heard of makeshift "bug cookers" made by wrapping the stack of wood in black plastic and leaving it in the summer sun for a day. That gets hot enough to kill them.

If you do nothing the life cycle continues, with beetles, eggs and new grubs until the whole piece of wood has been hollowed out to powder.

Ian

[samandothers]

Thanks Ian
I was afraid that was the answer...

However there are options to rid them!

[Handy Andy]

 I found 2 or 3 walnut boards with ppb in the white wood.  Put them in a tin bin in the summer, and that took care of them.  Not many hotter places than in a metal grain bin in summer.

[GeneWengert-WoodDoc]

The concern with spraying is that it does not stop the ones already in the wood that are eating and not coming out right away...a year or two sometimes.  Further, the spray does have to penetrate into the outside of the wood, as the eggs are laid in a nook crevice or cranny.  The borate spray is a water-based chemical, so we do add water back to the wood.  The wood must then be protected from rain, etc., as the borate can leach out.

In the U.S., selling wood that has a borate treatment requires one to notify the buyer that there is this preservative in the wood.  That is, you are selling wood and a chemical.  The chemical can be an issue in subsequent processing.

[WDH]

Remember this thread? 

https://forestryforum.com/board/index.php/topic,56850.0.html

Well, the PPB's were already in this when we sawed it.  We sprayed the lumber with borate, but it was too late, like Dr. Gene points out.  I took a leaf blower and blew all the little sawdust piles out of the stack so that I could monitor if they were still emerging as adults.  So far, minimal sign, but I can't be sure.  Over 1000 BF, mostly quartersawn.  High value wood.  Even though they are unlikely to re-infest the boards because of the borate, this wood will have to be heated to assure that they are not still in there.

[GeneWengert-WoodDoc]

It is much more likely that small holes and powdered frass when sawing are from ambrosia beetles (anobiid and not lyctid) that prefer wetter wood and also have a very short life cycle of a month or so rather than years.   As a result, they will not be present when the wood is dry.  However, they will be in any wood debris, so clean the air yard of such debris.  You cannot spray for them as they spend so little time in the ground or out in the open...good cleanliness is the best control option.

[Ironwood]

Straight Borate ( an earth salt) can be obtained from Southern States, Agway, and other farm suppliers as a powder in a 40-50 lbs bag. This is the main ingregient in Solubor and Timbor trade name products for timber homes and WAYY more $$$ than a "home brew" method. As stated it is water borne and should you choose to "add" a wetting agent to facilitate better penetration you are likely adding a chemical (some guys use gycol antifreeze, definitely a poison chemical) Anything to enhance wetting and hence penetration will help, this would include heated soaking vats, and ect.....

Ironwood

[GeneWengert-WoodDoc]

The active ingredient inTimbormand other borate based wood treating chemicals is Disodium Octaborate Tetrahydrate.  You cannot get good result from borate from a farm store and just adding water.  Never add glycol, as mentioned due to the hazard.  This hazard will stay with the lumber for years.  The user of the lumber is at high risk from illness.  It is illegal to use glycol, as well as diesel fuel to treat lumber.

Remember that borate based chemicals tend to leach out if exposed to water.  So, many uses would not be appropriate for borates.

Incidentally, to get some penetration of a chemical consider heating the wood first and then cool the solution.  The cooling will contract the air in the cells and "suck" in the fluid.  However, home treating effectiveness is not even close to proper commercial pressure treating.

[WDH]

Dr. Gene, I hope that these are ambrosia beetles, but I don't think so.  Usually ambrosia beetle holes are black around the edges, these are not.  Between the layers of lumber in the stack, there were perfect little pyramids of fine sawdust.  I have not seen this fine frass with ambrosia beetles.  Plus, there were some dead beetles that must have expired from the borate after they hatched out, and they look like PPBs.  They were longer and not as compact or fat.  I will take some pics of the wood for reference.  I am not sure that there are anymore dead beetles on the boards as the leaf blower did a good job of cleaning up the sawdust piles and the expired beetles.

It sure was a surprise and shock to see the damage as the log had been cut and stored on a large log yard for about 3 months before we sawed it and sprayed it with borate.  I could not believe it, and tried to tell myself over and over again that it was not PPBs, but alas, that is the conclusion that I came to  >:(.

[Ironwood]

Hole diameters are generally the tell tale sign of which critter your dealing with........

Ironwood

[WDH]

Exactly.  These are unfortunately smaller than ambrosia beetle holes, no black ring, and piles of sawdust.  If A=B and B=C, then A=C  :-\.

[GeneWengert-WoodDoc]

Not all ambrosia have the dark ring.  The hole size is the same as PPB.  PPB take quite a while to complete their life cycle...three months is quite short.  So, the short cycle, the borate spray (which probably washed off after the first rain and if straight borate and not the form used for insect control, did not much good), the bark on the log, and the high MC seem to make PPB very, very unlikely.

[WDH]

The log was harvested three of four months before it was sawn.  There was no bark on the log.  The lumber was cut and sprayed with a Disodium Octaborate
Tetrahydrate solution (20.9% boron) in a mix of one pound of borate per gallon of water.  The lumber was stickered in April under a shed open on three sides protected from any rain and has air dried for about 8 months, and it was a month ago that I saw the signs of the infestation. 

I sure hope that you are right that it is ambrosia and not PPBs.  What else can I do that will identify the culprit?