Woodworm treatment.

[Yorkie]

The problem with woodworm is that when you see the fine wood dust (known as 'frass') from the holes, it's too late - the holes are exit holes - not entry holes. It's a sign that the beetles have done their damage and scarpered. They have a long life cycle, and burrow away for years until the pupate. The worm have passed the larval stage and hatched into beetles. They then mate, lay their eggs in fresh wood beneath the surface (only one entry hole for lots of eggs to be laid), then the beetles dies - the adult stage is the end of their life cycle - they only live for days.

They usually look for end grain as an entry point - they don't for example burrow into the surface of a varnished cabinet. The cellular structure of wood can be likened to a bundle of straws - if we were a beetle, why would we try to fight our way through a tightly-knit bundle of straws when we can go in at the end of the straws? Different for the larva - wood to them is food, but the beetles aren't interested in food - they're dying already.

Wood that has exit holes is unlikley to have any beetles left in it, and while woodworm treatment of a say a woody cabinet or other item with exit holes will do no harm, it probably won’t do much good either – the larvae that caused the damage will have hatched into beetles and will be long gone, but in the unlikely event that there are still any larvae still within, at least the wood of radio cabinets is thin, so the liquid will get to them, and will kill any stragglers. Structural times are a diffrent thing altogether.

Trying to penetrate deep into timber such as joists etc by spray or brush is fairly innefective, but better than nothing. In houses in the south of France - where woodworm is endemic, the roof timbers - bascially round timbers from tree trunks with the bark shaved off - have tubes inserted into them permanently, through which woodworm treatment is periodically injected under high pressure by timber treatment specialists to ensure that the wood is saturated right through.

Woodworm treatment is best applied to uninfested timber as a precaution against infestation.

I've mentioned the beetles life cycle before, but it might stand repeating:

The wood-worming beetle’s lifecycle, (the most common of the four wood-worming beetles in the UK being the furniture beetle), goes like this:

The pregnant female starts the lifecycle by laying her eggs directly into the timber through cracks and existing holes. (To protect the eggs they aren’t left on the surface of the timber). The female beetle lives for only 10 - 14 days - her male counterpart - whose only role in life is to mate with as many females as possible, and doesn’t even eat - lives for only 3 -4 days, so the beetles themselves cause little or no direct damage to timber – it’s their offspring that are the culprits.

After a few weeks the eggs hatch downwards into the timber and produce larvae - this is the worm stage of the lifecycle, and the larvae carry on in this phase for anything from 2 to 5 years, munching their way up and down inside the timber, but this goes on unseen as they don’t emerge, having no reason to. It’s during this long phase of their lives that the structural damage is done, which is of course far more serious in load bearing structural timbers such as roof and floor beams, than in radio cabinets.
(The fine wood dust that they produce is known as ‘frass’).

Towards the end of the woodworm beetle lifecycle, the larvae pupate from the larval stage into adult beetles. The adult beetle then eats its way through the surface of timber producing the round exit holes that we see as evidence of the infestation which has taken place unseen over many years. Once the beetles emerge from the timber, in their brief life of just a few days they meet, mate, lay their eggs inside the nearest piece of wood that takes their fancy, to continue the life cycle. Then they die. Good!

Best of luck in your endeavours to defeat the little beasties Colin!