Death watch beetle in wood pile

[Zebra]

I turfed everything out of my woodshed in order to repoint it, since plants were growing through from next door. Upon examining the pile of firewood, I found that it contained holes approx 6-7mm in diameter, which weren't there before. Looked very much to me like death watch beetle!
Now it's true the timber was a bit damp in places. The door doesn't fit very well (I threw it together in an evening about 7 years ago from old roof boards) and the rain must blow in around it.
I have repaired the shed and put the timber back. I know I'm being silly but I'm just after some reassurance here. When I fetch those logs into the house some time in the coming months to burn them, there's no chance that the critters could escape into the house and do damage, is there? They don't hatch til spring, right? And if I can do something about the woodshed door so that the logs dry out now, they'll die, yes?

 

[paulc]

From my limited research, deathwatch beetle holes are only around 3mm in diameter. I have a pile of logs, some of which have partially rotted and become home to a number of bugs. One of them has produced some holes around 6mm diameter, and on digging the little blighters out, they are probably stag beetle larvae (or longhorn).
Last winter, I had problems with wasp beetle emerging from some logs after they were brought in to the house. To prevent a repeat, I have some smoke bombs to let off in the wood store. Hopefully, the pesticides they contain will kill off the bugs before I need to bring the logs in.

 

[Me!]

6 or 7mm diameter is much larger than any of the (many!) deathwatch holes we have in our timbers. They are all about 3mm or 1/8" diameter.
Does your firewood still have bark on it, and if so are you finding these larger holes mainly through the bark and into the wood just under it?
Personally I've not noticed any problems with logs that I have bought which have been properly dried before sale. Where I do have the active grubs is with wood I have cut myself from the garden and then stacked to dry for a couple of years with its bark still on. Those sometimes have 6 or 7 mm diameter holes appear in them which upon investigation have had a large white grub in them. I don't know what they are, but they are not deathwatch.

 

[Flyfisher]

I don’t know the answer but it would be a great pity to destroy any stag beetle larvae.
Hopefully Matt Green will be along soon for a more expert view.

 

[Pennyviz]

they do sound like stag beetle larvae, I saw a few similar in an old tree stump in our garden, they are quite rare now - any chance the logs could be dumped in a corner outside somewhere? Save your anxieties about deathwatch and good for ecology?

Penny

 

[Matt Green]

Hello, I trust everyone is well.

6-7mm is too large for DWB, I think paulc is right to suggest longhorns- they would be my first thought. I dearly wish they are stag beetles as they are rather rare these days but their larvae need very rotten timber to move through of the sort of degree of decay that you only find in very rotten stumps or trees well decayed in ground contact. The ones I found years ago were in sections of trunk left in a garden after a felling 4 years previous that were just about turned to mush by white rot decay.

 

[a twig]

As someone who has had deathwatch beetle over the last few years, those holes are definitely too large. Ours were 2mm at most.

With repairs to the shed and hopefully everything drying out, the beetle should be forced to move on through lack of food. Equally shouldn't be a problem if any make it indoors unless you have a prevalence of damp timber knocking around, in which case I would suggest probably larger issues are afoot that a couple of incognito beetles!

 

[Zebra]

Sorry everyone, my ruler had become uncalibrated, as had my eyes. The holes are 3mm in diameter.
But it's funny you should all mention beetles. I did have an infestation of beetles this summer. I had never seen them before, but googling them, I reckon they looked like Wharf Borers. They kept appearing inside the house, and I didn't know where they were coming from. Maybe these two things are linked.
I can't seem to find what size holes Wharf Borers make.

 

[Pennyviz]

What kind of wood was it? A couple of years ago I brought in wood from our felled ash tree and had zillions of ash wood bark beetles everywhere.

Penny

 

[Zebra]

Oak. Felled six years ago.

 

[Pennyviz]

Oak. Felled six years ago.

Scratch that theory then

 

[88v8]

If the wood is thoroughly wet, in a shed it will take a long time to dry.
I made a dedicated shed for our wood, with a raised slatted floor and the sides all slatted. Watertight but well ventilated. Around 4' x 7' it loads through two doors sideways on, I can stack about 3 tons.

In general I take the view that if conditions in the house are conducive to beetle, it will get in there anyway. So when I've had wood with worm, I've always used it, but having said that, I don't leave it to sit for weeks in the house.

Ivor

 

[Matt Green]

Even 6 year old oak will be too dry for wharf borer. Could be deathwatch beetle but dry the timber out and the larvae will die inside it or the adults will leave to lay eggs in wet timber. Either way the dry timber in you house will not be at risk from deathwatch beetle attack.

 

[Zebra]

Thanks Matt and Ivor. Exactly the sort of reassurance I was after.

 

[Zebra]

Even 6 year old oak will be too dry for wharf borer.

But the wood got wet because the door on the shed has gaps around it so the rain gets in, and the wood was on the floor with no ventilation. So it's sort of irrelevant how old the wood is. I only said that to indicate it wasn't green.
New / altered shed door has gone on my list of jobs!!

 

[paulc]

If you can find some pallets, stack the wood on them. The pallets helps to isolate the wood from a damp floor and also allows air to circulate under the pile.

 

[a twig]

If you can find some pallets, stack the wood on them. The pallets helps to isolate the wood from a damp floor and also allows air to circulate under the pile.

Good advice, my wood shed (although it has rubble stone walls) has a "suspended floor" entirely of pallets which works wonders.

 

[Zebra]

Thank you, yes, my woodshed is only tiny, the size of a larder, so I got some pieces of old scaffold board and some 4x2 and have built a little suspended floor, bricks on the floor, some joists on the bricks, and then scaff boards. Let's hope that makes a difference.

 

[Matt Green]

Even 6 year old oak will be too dry for wharf borer.

But the wood got wet because the door on the shed has gaps around it so the rain gets in, and the wood was on the floor with no ventilation. So it's sort of irrelevant how old the wood is. I only said that to indicate it wasn't green.
New / altered shed door has gone on my list of jobs!!

It will take a while for oak to lose enough durability and density from rain water for wharf borer to become an issue. They feed in really soft, knackered, timber.