woodworm holes suddenly appeared in new build bookcase

[Jacob]

Explain please@XTiffy ? Do woodworm prefer sapwood?

Yes especially in oak where they can reduce the sapwood to crumbs without touching the heart. Other timbers they can go for any part near the surface of a board, sapwood or otherwise. Even then they seem to be selective - I've had sycamore boards where some parts are riddled and others untouched.

 

[Adam W.]

Do woodworm prefer sapwood?

It has a high starch content, which bugs find quite yummy.

 

[XTiffy]

pe2dave,
Yes, the sapwood is extremely susceptible to infestation by woodworm or in other parts of the world much bigger beasts! When at College (1977) studying Antique Furniture Restoration. We had a lecture from a Rentokil scientist on the subject, extremely interesting. I have before cut away (walnut) sapwood showing signs of flight holes but did not find the tracks on the heartwood. Incidentally that lecture gave the life cycle as approx. three years and in that time the grub travels around 10 inches before biting through the final piece between May and June (typically), then becoming a "fly" and starting the cycle all over again.

 

[recipio]

I once sliced a woodworm tunnel exactly in half on the table saw and there at the end was a white grub. It was tiny - just over a mm and had a lucky escape ! It was yellow pine and went straight into the stove. Even resinous softwoods won't put them off.