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There may be a kind of Powderpost Beetle attacks WO heartwood...

Started by Dough_baker, March 07, 2015, 11:38:34 AM

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Dough_baker

Hello, good evening,

Most textbooks and web sources say that powderpost beetles only attacks sapwood, especially unfinished lumber.

However, I have seen a few cases that they attack heartwood heavily.

The following photo, a batch of european white oak 50mm lumber, air dried for 3 years in Germany. About 700 BF in this 3800 BF batch is completely damaged by beetles. I believe that the damage happened during drying, because there is no hint of any beetle activities (wood dust) after delivery.



The second picture, a 2'' european WO slab, air dried by myself, heartwood attacked by beetles during drying period slightly.

I treated all sapwood with borate ASAP after milling, next time, I'd better to treat all surfaces.  :(



Best,
Baker

red oaks lumber

the pictures almost look as tho the bugs got in when it was still in log form. iv'e had logs lay for a period of time before sawing and thats what it looked like, which might explain the lack of beetle dust. sorry i can't be more specific towards your question :)
the experts think i do things wrong
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WDH

Those holes in the first pic actually look more like ambrosia beetle holes to me than PPB holes.  PPB holes are filled with frass.  Ambrosia beetle holes are not, and many times the wall of the tunnel is stained black by a fungus. 
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Dough_baker

Quote from: WDH on March 07, 2015, 09:29:54 PM
Those holes in the first pic actually look more like ambrosia beetle holes to me than PPB holes.  PPB holes are filled with frass.  Ambrosia beetle holes are not, and many times the wall of the tunnel is stained black by a fungus.

Thanks WDH, I am going to google ambrosia beetle.

Dough_baker

Quote from: red oaks lumber on March 07, 2015, 01:02:21 PM
the pictures almost look as tho the bugs got in when it was still in log form. iv'e had logs lay for a period of time before sawing and thats what it looked like, which might explain the lack of beetle dust. sorry i can't be more specific towards your question :)

Yes, there are some holes must exist when is was a log. Some may appeared after milling. WDH said that it may caused by ambrosia beetle, I am going to see whether borate could prevent attack. :)

SLawyer Dave

The hole size seems to me to indicate a type of PPB rather than Ambrosia.  Ambrosia beetles are not really considered "structural pests" of note, because they really only attack dead wood that has a rather high moisture content, (similar to dampwood termites).  So in a structure, if you have either, then you really have a problem with an excess moisture condition and eliminating that excess moisture will cure the infestation problem.  Ambrosia beetles don't eat the wood, but rather the fungus that they cultivate within the galleries of their tubes that they chew out of the dead wood, (which is often softened due to the high moisture content within the infested wood).  So generally Ambrosia Beetle tracks are larger and have residual black staining from when the fungus was active.  In trees and lumber, almost all Ambrosia infestations occurred either in the forest before harvesting, or if the log was stored for a prolonged period of time in a very moist environment before processing. 

There is a long history of both bulk wood and finished wood products being imported from Europe and Asia that are infested with PPB.  That is why most wood and their products are required to be fumigated before export modernly.  PPB can exist in wood for decades before enough damage and "holes" appear to make a consumer wonder what is happening to their imported furniture.  Generally PPB prefer to attack the sap wood of unfinished wood, however, if that wood was infested prior to the wood being used in making a finished wood product, then that "finished wood" can still maintain an active infestation.  As to "heartwood", like most wood destroying insects, PPB look for the path of least resistance.  Sapwood is generally softer than heartwood, so they will attack it first.  However, in heavy infestations, or where the heartwood may be soft enough, if that is the wood the PPB has available to it, then it will do its best to eat it. (In its larval form when the damage occurs, the PPB can't just choose to leave to another wood source, its stuck in the tree/wood where the egg was laid).

Given that Dough_Baker said there was no powder coming out of the lumber, I would be fairly certain that the infestation occurred prior to cutting of the tree into lumber.  When you have an infected log, and then cut that into lumber, most of the "dust" is going to filter out of the holes during that process.  Active infestation can continue to occur in the cut lumber, but that should produce additional dust.  I suspect in this situation, the wood was probably fumigated shortly after cutting.


GeneWengert-WoodDoc

Ambrosia and PPB have the same size hole.  In fact, ambrosia is the only common insect that has these small holes, other than PPB.  It is extremely likely that this is ambrosia, because the heartwood is not attractive to PPB.

The ambrosia beetle likes to breed in wood debris and wet soil around the lumber stack.  So, never allow any wood debris in the air drying yard.  Keep the yard clean and well drained and you risk is ambrosia is very small.  The problem with borates that are formulated for wood preservation is that the borate is soluble in water, so in a rain, the chemical washes off and there is little or no residual protection, especially on the surface where the risk of infection is highest.

Ambrosia also likes to infect the stickers, so unless you run the stickers through the kiln so they achieve 130 F throughout the wood (when being used or just before they are reused if they were stored outside very long), the most likely source of the insect is from the stickers.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

WDH

In the first pic, I believe that I can see some of the black stain from the fungus.  Fortunately, the ambrosia beetles leave very soon after the wood is sawn, but they leave those tell-tale black fungal lined holes behind.  Just a cosmetic issue after that, unlike with the PPB.
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

SLawyer Dave

Baker indicated that the second picture showed "damage" that occurred after the wood was cut to lumber and while he was air drying it himself.  While as I mentioned, my certifications did not include Ambrosia Beetles, we were taught in our certification classes that Ambrosia are not a threat to cut lumber or structures, (as WDH posted about).  So could the damage that occurred during drying, after being slabbed, really be from Ambrosia Beetles? 

Lawg Dawg

Whatever it is, it looks like there's a whole bunch of them...not a good sign smiley_inspector
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GeneWengert-WoodDoc

Ambrosia beetles can attack wood after sawing until the MC of the wood they are eating is under about the 25% MC range at the location where they are active.  In other words, they are commonly associated with early stages of air drying (or often earlier).  I was told that when the wood went under 30% at the point of attack, their jaws were not strong enough to damage dry wood.

Note that the holes are exit holes.  The attack can occur before sawing or early in air drying, but the exit holes occur later.

As I mentioned, they can get into wet stickers, or wet wood debris in the air yard, and that is one way to transfer them from one load to the next.  Oftentimes they have three crops of insects a year.  Unlike PPB that can take six months to three years to exit after the eggs are laid, these ambrosia beetles can exit in a month or so in warm weather.

They get their name from the ambrosia fungus that is on the feet of the parent, that infects the wood where the eggs are laid, and that is then the food for the larvae.  The dark color of the fungi is what creates the ring around the holes.

These insects can also attack a log laying in the woods for a while.  Much of the literature is about log damage.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

WDH

There can be eggs and larvae in the wood in the log form.  Then you saw the boards, and everything looks fine.  Then the baby beetles hatch and bore out of the wood.  Mostly what you are seeing are exit holes. 
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Magicman

Commercial furniture makers often try to imitate those ambrosia beetle holes by putting black dots on the lumber before the final finish is applied.

In the 80's I made and sold over 100 clocks, a bedroom suit, and several other furniture pieces using "beetle hole Pecan" lumber.  Customers overwhelmingly chose it over the "clear" lumber.  It was a sad day when that whack of lumber was gone. 
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Tom the Sawyer

Had a client last fall who was hoping that his white oak had bugs.  He had seen a table made from what he referred to as "wormy white oak" and had been looking for a log with bug holes.  He had a standing order from a buddy who would build a table for him if he could find any. 

He was so happy when this is what we found when we opened the log.  Made his day.  We got 5 - 9/4x16"x8' planks plus a bunch of smaller pieces.


 
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It's Weird being the Same Age as Old People

Never allow your "need" to make money to exceed your "desire" to provide quality service.....The Magicman

WDH

Good old ambrosia beetles.  Down here, when it gets warm, just let the pecan logs sit for a spell.  You will end up with wormy pecan.  They love pecan  smiley_devil
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

Dough_baker

Quote from: SLawyer Dave on March 08, 2015, 02:40:49 PM
The hole size seems to me to indicate a type of PPB rather than Ambrosia.  Ambrosia beetles are not really considered "structural pests" of note, because they really only attack dead wood that has a rather high moisture content, (similar to dampwood termites).  So in a structure, if you have either, then you really have a problem with an excess moisture condition and eliminating that excess moisture will cure the infestation problem.  Ambrosia beetles don't eat the wood, but rather the fungus that they cultivate within the galleries of their tubes that they chew out of the dead wood, (which is often softened due to the high moisture content within the infested wood).  So generally Ambrosia Beetle tracks are larger and have residual black staining from when the fungus was active.  In trees and lumber, almost all Ambrosia infestations occurred either in the forest before harvesting, or if the log was stored for a prolonged period of time in a very moist environment before processing. 

There is a long history of both bulk wood and finished wood products being imported from Europe and Asia that are infested with PPB.  That is why most wood and their products are required to be fumigated before export modernly.  PPB can exist in wood for decades before enough damage and "holes" appear to make a consumer wonder what is happening to their imported furniture.  Generally PPB prefer to attack the sap wood of unfinished wood, however, if that wood was infested prior to the wood being used in making a finished wood product, then that "finished wood" can still maintain an active infestation.  As to "heartwood", like most wood destroying insects, PPB look for the path of least resistance.  Sapwood is generally softer than heartwood, so they will attack it first.  However, in heavy infestations, or where the heartwood may be soft enough, if that is the wood the PPB has available to it, then it will do its best to eat it. (In its larval form when the damage occurs, the PPB can't just choose to leave to another wood source, its stuck in the tree/wood where the egg was laid).

Given that Dough_Baker said there was no powder coming out of the lumber, I would be fairly certain that the infestation occurred prior to cutting of the tree into lumber.  When you have an infected log, and then cut that into lumber, most of the "dust" is going to filter out of the holes during that process.  Active infestation can continue to occur in the cut lumber, but that should produce additional dust.  I suspect in this situation, the wood was probably fumigated shortly after cutting.

Hello SLawyer Dave, thanks for your information and analysis : ) The slab in picture 1, there may be both PPB and AB damage, the sapwood is full of holes, soft as cookies, can be easily broken off. Most likely, this wood was fumigated before export, I never saw any living beetles or larvae.

The damage to heartwood really cause loss (or trouble), although there are clients looking for wormy lumber, it is still a very niche market, not easy to find.

I have never seen so much holes on heartwood of North American kiln dried lumber.

Dough_baker

Quote from: GeneWengert-WoodDoc on March 08, 2015, 03:46:16 PM
Ambrosia and PPB have the same size hole.  In fact, ambrosia is the only common insect that has these small holes, other than PPB.  It is extremely likely that this is ambrosia, because the heartwood is not attractive to PPB.

The ambrosia beetle likes to breed in wood debris and wet soil around the lumber stack.  So, never allow any wood debris in the air drying yard.  Keep the yard clean and well drained and you risk is ambrosia is very small.  The problem with borates that are formulated for wood preservation is that the borate is soluble in water, so in a rain, the chemical washes off and there is little or no residual protection, especially on the surface where the risk of infection is highest.

Ambrosia also likes to infect the stickers, so unless you run the stickers through the kiln so they achieve 130 F throughout the wood (when being used or just before they are reused if they were stored outside very long), the most likely source of the insect is from the stickers.

Hello Dr Wengert, I have printed a copy of Drying Hardwood Lumber and started reading. Slow air drying can lead to a few trouble, Although Shed method described in this report is used successfully for all thickness of oak, much attention still should be paid on insect and stain control. I am also seeking approach for rapid drying, have got useful info from Den.

Dough_baker

Quote from: WDH on March 08, 2015, 08:07:37 PM
In the first pic, I believe that I can see some of the black stain from the fungus.  Fortunately, the ambrosia beetles leave very soon after the wood is sawn, but they leave those tell-tale black fungal lined holes behind.  Just a cosmetic issue after that, unlike with the PPB.

Yes, WDH, it is a cosmetic issue, I give one slab to my friend as a piece of outdoor garden furnitre, if I don't plane it, the holes are not as obvious as these in picture 1.

Dough_baker

Quote from: SLawyer Dave on March 08, 2015, 08:28:08 PM
Baker indicated that the second picture showed "damage" that occurred after the wood was cut to lumber and while he was air drying it himself.  While as I mentioned, my certifications did not include Ambrosia Beetles, we were taught in our certification classes that Ambrosia are not a threat to cut lumber or structures, (as WDH posted about).  So could the damage that occurred during drying, after being slabbed, really be from Ambrosia Beetles?

SLawyer Dave, I treated all sapwood with borate, maybe the PPB's eggs laid on sapwood are all killed.  :o what do you think about?

GeneWengert-WoodDoc

Remember that the holes are exit holes, so the infection can occur in the log but not be seen until the lumber is made and stacked.  The insect is doing damage within the wood, making tunnels and decreasing the wood's strength for a while before the exit holes appear.  A lot of exit holes mean a lot of the insects were active in the wood prior to their exit.  Eventually, the insects exit the wood to breed and start a new cycle in very wet wood.

If infected wood is sawn and dried quickly, the insects can tunnel within the wood prior to drying but be unable to exit because the wood is too strong for their jaws to cut.  Or the heat can kill them.  So, their damage may not be seen until planing exposes the interior tunnels.  So, basically, they need wet wood to exit.  Note that PPB do not like really wet wood, so the two insects would not both be active at the same time.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

WDH

What amazes me is how fast they complete their life cycle and leave the lumber after the infested log is sawn and the boards begin to dry.  They seem to be running from the drying. 
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

GeneWengert-WoodDoc

Heat seems to send a signal to them to exit and breed.  I can see that lumber stacked for drying will often have more heat than a log.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Cazzhrdwd

Does seven dust work on them? I have problems with them while letting poplar air dry.
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Cazzhrdwd

Now I'm doing red oak and I can see the start of them burrowing into the fresh cut log. My problem is it takes a month for oak to dry in my L200m, which means I can't raise the temp up until the lumber is below 25%mc. What should I do?
96 Woodmizer LT40Super  Woodmizer 5 head moulder

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