Capricorne (long horn beetle) treatment


(Dave Smith2) #1

Hi guys n gals... wondering who can help with this? (I think I saw something on here before but can't find it at the moment). We moved into an old house with exposed beams, used to be just a summer vacation house, and now have fresh emerging capricorne beetle holes in the beams (despite the diagnostic eport saying no signs of any!). We've just had a quote from Rentokil to inject just the beams and it's silly money... couldn't believe what they quoted! It's just 2 days work to drill the beams, fit injectors and inject the product. Anyone got any advice, where I could buy the equipment to do it myself for example, or any other companies who are reputable and reasonable. I'm in the middle of Tarn et Garonne, Tarn and Aveyron in the Midi Pyrenees. The local Mairie couldn't help, but did give me a couple of numbers for local menuisieres that I'm going to call. I've already sprayed xylophene into all the holes and then painted the surface with xylophene gel, but need to drill and inject under pressure to treat the heart of the wood.
Any help much appreciated! Thanks in advance.

(Kate Ryley) #2


I have a related question and wonder if you learned people can help.

We are looking at buying a house and a couple of the posts on the hangar have quite a few holes in them. The building is old and dry so from what you've been saying, the wood should be OK now. However, it looks like a woodpecker has been hacking away at the edges of the holes or maybe it's the bugs themselves? We were wondering if that means there are still larvae/beetles or other crawlies in there that we'll need to treat? Would hate to spray anything nasty out there if we can avoid it. Would appreciate your advice. Attached are a couple of photos.

(Dave Smith2) #3

Thanks Chris, that's great! I agree, the large ones definitely look like they are Leptoglossus occidentalis Western conifer seedbug. That's a great relief! I've just got to be sure the exit holes we have, which look recent, are in fact old ones. Thanks once again, really appreciate your help. I'm cutting back on the toxics now, just a little preventative work.

(Chris Luck) #4

They all would seem likely to be Leptoglossus occidentalis Western conifer seedbug in various stages of development.

See this page HERE

Most people recognise the more obvious "sheild bugs" or "stink bugs" without realising how many different types of Hemiptera there are including aquatic species.

Anyway, harmless and dare I say it, most creatures are when identified correctly.

Try not to make your part of the planet too toxic.


(Dave Smith2) #5

Thanks Chris... will be interested in the ID later. That link is great! The smaller light brown ones do resemble Gonocerus acuteangulatus but I can't see the larger darker ones. They seem to have the two dark spots on the abdomen which, somewhere, I read was a sign of Hylotrupes bajulus. Look forward to the ID, but that's great news! We do have lots of what look like recent exit holes in the beams and the detritus is still very light and powdery - although having said that, there's old damage to lots of the pine floorboards and that detritus is still light and powdery too.
Look forward to hearing more and really appreciate your expertise Chris.

(Chris Luck) #6

They are all harmless "true bugs", types of shield bug that are overwintering as adults. Punaise in French. There are several pages at this link !!!!!


I can ID them later but they are I repeat harmless.


(Dave Smith2) #7

Hi Chris, I'm going to attempt to attach some photos, here goes!
I think the larger, darker ones are Hylotrupes Bajolus (?) but I don't know about the smaller, lighter brown ones.
All of these I have caught live inside the house in the last month. Some may have come in on firewood ( we have 2 woodburners) but more liklely the winter heating has fooled them into emerging!
Would be grateful to hear what you think. Many thanks!

(robert moon) #8

Yes, identifying your enemy is very important, you wouldn't treat cockroaches with ant powder, flies with rat poison etc.

Xylophene is designed to kill xylophages, containing perméthrine has a label saying "dangerous for the environment" so not to be emptied down the drains or toilet. Keep away from fish. Used in a responsible manner, it does a cracking job.

Same as neonicotinoids, used responsibly is a cracking insecticide, unfortunately it's sprayed loosely from a tractor and unsurprisingly not only does it kill aphids, bees are also killed, hence it's banned.

Incidentally, farmers and ZNA (Zones Non Agricole) commercial gardeners using professional products will now have to do the Certiphyto exams. That's a good thing, as they will learn what chemicals do, not what the salesman tells them it does!

(robert moon) #9

Exactly, If you treat then varnish, you shouldn't need to treat for 10-20 years so you should be fine. Just be careful when treating floors, I did a house the other day and the floors were like walking on ice. Great training for the next curling Olympic team!

(Brian Milne) #10

I agree, but within reasonable limits. The point at which it becomes an'infestation' is crucial and not, I agree with David and yourself effectively, when one of the companies points out a hole and says 'infection'.

As for termites, OK everybody they can be a problem. This house has had them and eventually we have some totally 'porous' beams to replace. However, termites are actually part of an important ecological cycle. When they feed normally, then they clear deadwood in forested areas and also inhibit fungi that would also damage/destroy healthy, living trees. In principal I have nothing against them. Like some other people, we have pieces of pipe in the ground here and there into which we occasionally put organic paper, which they would have away toute suite, to see if they are around. If they are then we will do something about it. We would not dream of 'treating' the whole area to make sure they are dealt with. Firstly it is a con and secondly the awful substances used kill every other living thing and pollute surface and ground water alike. Where somebody had his ground treated I saw dead birds everywhere and could have wept.

All for the sakes of making a profit not saving anything though.

(Chris Luck) #11

The point here, and I suspect Rob may agree, is that people are conned out of thousands of €'s to provide treatments that aren't actually required.

The broader message beyond this thread about suspect wood borers is that we fail our duty to protect the wider environment if we simple kill other creatures due to a lack of knowledge and understanding.


(Dominique Rogers) #12

It is true that identification of the bugs is important but then I remember one of my colleagues murmuring at one of the countless conferences on the subjects one attends quietly through his teeth "I do not give a f..k about their life cycle, I want to KILL them" and in real term this is the point. KILL KILL thank you for the French ignoring H&S rules and producing xylophene.

(Chris Luck) #13

Any photos can be posted on here or sent to me directly anytime by anybody and I will do by best with them. Ideally with any photos of damage and stating the condition and species of timber.

Equally I'm happy to try and identify any other species people are concerned by or simply interested in.

Try to post or send good focus photos of un-squashed creatures, one squidgy blob with a few legs looks much like another.


(David GAY) #14

I fear Chris you are wasting your time. People don't seem to want to listen to the science. From time to time over the last 30 years we have seen Capricornes flying but one or two per year. I recently was cutting up some oak beams which were installed more than 100 years ago so the beams thenselves would have been 250 years old when installed. Not only had they been in a fire which had charred no more than 10 mm of the beam but the heartwood of the beam was rather like cutting into a piece of steel. Any capricornes might have enjoyed the sap wood of which there was no evidence but in the beam itself no evidence of any atttack. What oak and chestnut but not elm really fears is damp. High moisture encourages both fungal attack and the depredations of termites. In my opinion a lot of money is made on the basis of people's fears rather than the reality of any threat. The old adage that what a house needs is a good hat and sound boots is good advice. Dry wood discourages both insect and more importantly fungal attack.

(Dave Smith2) #15

By the way Rob, I was thinking of painting the floorboards after sanding and treating them (we just have a rug, not fitted carpet) - do you say don't paint or varnish because it's hard to treat again in the future?

(Dave Smith2) #16

Thanks again Rob... all useful info :)

(Dave Smith2) #17

Thanks Gordon... though as mentioned, at the first sign of a bit of timber that was covered, the Rentokil salesman said they wouldn't be able to give a guarantee... and still no drop in cost due to not having to pay insurance!

(Dave Smith2) #18

Thanks David... yes, despite the 'diagnostic' reports being ok, I have had to install a new fosse septique plus the timber problem now. The seller's agent was very insistent that they have the 'vice caché' clause in the contract !!

(Dave Smith2) #19

Thanks Dominique... and glad to hear you didn't have termites!

(Dave Smith2) #20

Thanks Peter... really appreciate everyone's advice and info.