Monday, November 23, 2009

Borer eating your home?

Good Morning Followers……….or should that be follower?

I have such an ‘interesting’ life. I am off to the National Possum Control Agencies Technology Transfer Conference in Wellington this evening. It will be two days of hearing about and talking about the best ways to stop possums damaging New Zealand’s environment and transmitting tuberculosis to cattle, deer and other animals.

1080 is a popular subject for discussion among delegates. Most of those in the industry would welcome an alternative if it was as cost effective or the money was forthcoming to use the more expensive options that already exist.

Kiwicare manufactures NO Possums Cholecalciferol Gel Bait which is a very novel bait. It will remain effective over long periods (up to 26 months) so that time spent replacing deteriorated bait is saved and control is maintained over extended periods. The gel formulation and use of choleclciferol (vitamin D3) as the toxin makes the bait unattractive and of low toxicity to birds. Cholecalciferol also has low eco-toxicity as it does not build up in the food chain reducing risks of secondary poisoning of scavengers. The bait is available for use by anyone wanting to control possums, even if it is only to stop them eating the roses in your garden or you want to protect the block of native bush on your lifestyle block. It does not require a licence.

Enough of possums! I was supposed to be talking about borer. A rather different type of pest problem. Borer (also known as woodworm) are small brown beetles whose larvae eat their way through soft timbers including our weatherboards, floorboards, joists and furniture. You will know you have a problem with borer if you see small holes (flight holes) in your wood as if someone had thrown a dart into the wood. These holes are where the borer beetle has emerged after 2-4 years as a larva. The majority of these holes will be found in dark areas where the humidity is higher, e.g. under the floor, inside the walls and in a roof space if there is a roof of concrete or terracotta tiles.

The good news is that you can easily stop the borer damage. Treat the timber. If the timbers can be accessed they can be sprayed or painted with products that kill the larva and prevent new infestation for many years. On painted, varnished or polished surfaces the flight holes can be injected. Even when the affected wood cannot be accessed at all the use of borer bombs can control the adults and slow down their re-infestation of the timbers.

I have often heard it said that a house has never fallen down due to borer damage in NZ. This might be true, but it is only because most houses are only now old enough to have been that heavily damaged (it takes at least 50 years) and houses are condemned before they fall down.

This is the flight season (November-February) when adult beetles emerge from the timers and this is when borer bombs are most effective. The other treatments are equally effective at all times.

Save your property. Act now.

One woodworm asked her boyfriend. “How’s life?” she asked.
“Same as usual,” he replied, “boring.”


  1. I only want to use non-toxic elements in my home. Is there a non-toxic product i can use to get rid of my borer problem?

  2. Hello Katlyn,

    I wonder if I just answered your question on another website. I will copy that reply here:

    Permethrin is the active ingredient of most borer treatment products including NO Borer from Kiwicare. Permethrin is a synthetic version of pyrethrum that is extracted from chrysanthemum flowers and has the same mode of action but is designed to remain effective and protective for much longer. Permethrin is toxic to borer but of extremely low toxicity to you or me and that is why it is used in many common household insecticides.

    The other treatment used to get rid of borer in infested timber is sodium octaborate. This is also of very low toxicity but it requires the timber to be very well saturated to leave a high level of the chemical on the timber where borer would attack it. It is usually only used by professional operators with the correct equipment.

    You can prevent borer attacking timber by using ready treated timber or hard heartwood timbers which borer cannot attack. Also borer do not lay eggs on painted or varnished surfaces. The problem with painted weatherboards is that the borer attack from the unpainted surfaces inside the wall.

    I hope that is of help.

    I will add here as I should have mentioned on the site, that borer like timber that contains a little moisture. That is why they attack floor timbers where the moisture from the ground keeps humidity higher than in the roof. So check that there is good ventilation to timbers and fix any leaks. A dehumidifier and/or air conditioner will help to dry out the interior of a house and reduce borer attack.




Please feel free to ask me a question or comment on this blog.

You may find information you are looking for here.