woodworm holes suddenly appeared in new build bookcase


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21 Dec 2008
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Sheffield uk
Over christmas and new year this year i built my wife a bookcase out of french oak
suddenly this week theres lots of piles of dust on horizontal surfaces and some on the floor
i can see holes under the little pyramids of dust
I did use some of the sapwood in the top and teh holes only seem to be in the sapwood

what should i do?
i have some woodworm eradicating fluid...do i just treat the holes or the whole bookcase...what about other wooden things in the same room?
At least the exit holes mean that some of them have left!
This is the time of year, warm, humid etc. They tend to come out together as they are looking for mates. I spotted some two weeks ago and was stubbing them out on some sawn sycamore boards.
There will be more in there to come next year but woodworm polish or fluid will fix them. No need to over apply it - it just needs to be on or in the surface.
The ones who manage to reproduce may attack other wood but I always get the impression they are species specific, or at least selective, and are most likely to lay their eggs in your oak again, other stuff may be untouched.
I used https://www.amazon.co.uk/Decco-Rentokil-FC20-Classic-Polish/dp/B00DVJOIGO on a wormy old wardrobe and it seemed to work but you never know it might have been an old attack long since gone. Piles of sawdust means they are still at it. Little brown beetles hovering about are the sure sign and urgently time for an insecticide aerosol.
But don't panic they are slow and steady workers - it may not seem like it when you first spot them but they will have been at it for years.
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The ones here..came out of ( now deceased ) MIL's "antique" Chestnut dresser, ( given to her at a "discount" in lieu of wages by her antique shop owning boss when she was younger ) went into oak ( french natch ) floorboards, came of of there , went into pine door ( yes I know ) , came out of there and went into some unknown Chinese wood bit of scrollwork..when we moved in I decided to "nuke from orbit"..some still came back..Nuked again..crossed fingers , not seen any since. The deathwatch beetle however..I can hear occasionally, means the bedroom boards and joists are all going to have to be replaced...sigh

if the French had used insects against the English longbow men, history would have been very different .
So.... are these holes and piles of dust caused by something? ....flying things walking things wriggly things.... going in or coming out ?
As Jacob indicated, they're exit holes, and most likely those of the now mature and flying common furniture beetle or anobium punctatum. They emerge and look to mate and lay eggs in crevices in the wood (coarse grain, cracks, splits, etc) or intersections where two pieces of wood meet, e.g., somewhat gappy shoulder lines of M&Ts, end so on. Furniture beetle likes oak sapwood because it's nutritious, and less fond of heartwood because it's less nutritious, but given time the beetles will tunnel voraciously in both wood types.

It's likely there are still a number of less mature beetles burrowing away in the wood so repeated treatment with furniture beetle killer would be advisable over the following two, three or four years. The treatment doesn't kill the beetles because it's topical, and they're well below the wood surface, but it affects the emerging adult as it chews through the treated upper millimetre or so of the wood and the ingested chemicals harm the adult, and if harmed enough it dies and therefore has a reduced chance of reproducing.

It's reckoned that wood at or below 12%MC is an especially difficult environment in which the common furniture beetle can survive so, assuming your furniture is now at or below that moisture content, it's likely the problem will diminish over a year or two and then stop, especially if you undertake treatment. My experience of furniture in habitable buildings, i.e., it's dry at around 12%MC or below is that common furniture beetle infestation or reinfestation is highly unlikely. On the other hand I've come across examples of furniture stored in relatively damp locations for fairly long periods, in such as outhouses, sheds, damp(ish) furniture repositories and the like, that have become infected.

I suspect the infection, or perhaps repeated infestations, happened prior to you building the piece when the wood was wetter; perhaps it was only air dried and didn't get a higher heat treatment that kilning would induce which would have gone a long way towards killing any existing grubs in the wood. An alternative might be that the wood was kilned and subsequently was stored in conditions that were moist enough (atmospheric relative humidity plus wood moisture gain) that made it attractive to the adult beetle. All the previous in this paragraph is pure guesswork or speculation as I have no idea of the wood's history. Slainte.
From woodworm to earworm in less than 10 posts, that's impressive thread drift :ROFLMAO:

Don't say I never give you anything:

The grubs live in wood for years - typically upto 5 - before burrowing out and flying off to mate in the insect stage. Chances are there are more still eating away at the bookcase.
Woodworm treatments are generally surface applied borax compositions. This is ingested on the way out of the wood and makes the insect sterile so breaking the cycle. If you treat the bookcase, then in theory you should be good, and protected against the laying of new eggs too, but the surface treatment won't affect the bugs munching away inside the timber for a few years until they head out.
Certainly - well I can buy it in Bar or Cone form from CooksonGold - it's used as a flux for Silver / precious metal soldering.
Boron is good stuff and relatively safe
"Although they are highly toxic to insects, borate treatments are extremely low toxicity for humans and other mammals. Additionally, borate treatments are long lasting and do not affect the appearance or function of the wood."
https://www.lovittscoatings.com/Is-...hey are highly toxic,or function of the wood.
Did our suspended ground floor with it to fix dry rot. Seems to have worked - and it doesn't harm mammals we've still got mice as fit as fleas.
Good to see the safety elves haven't managed to force everyone to buy "branded solutions", instead of being able to buy the chemicals one wants. One of the best things I had as a kid was my chemistry set, and a chemist's shop where you could buy packets and bottles of chemicals. Was worried that all that might have gone.Homemade rocketry and things that go bang with interesting colour smoke. :cool:
Maybe put the bookcase into quarantine until you are sure ,, treat with suitable treatment and monitor other items just in case . If you spot anything else you can be ready to pounce. Good luck 🤞
As an antique restorer, I used woodworm treatment injected into the flight holes using a hyperdermic (from a friendly vet, they use large ones). This will penetrate much deeper and kill off any that are still to fly. As you will see from the flight holes, they are pretty small. Then keep up the surface treatment.
In future do not use sapwood!