[Alan Douglas]

I don't know the life cycle of Irish woodworms, but here we have powder-post beetles. The adult insects lay eggs on suitable wood (the right moisture content, not finished, some wood species preferred over others), and the beetles start boring. After many years (at least ten, I believe) they emerge and fly off to lay more eggs. The holes are emergence holes, so it does no good to use insecticide there since the beetles are long gone. Also most insecticides won't penetrate solid wood. Certain levels of heat or cold will kill them. I think the safest is what museums do, enclose the items in a bag filled with carbon dioxide.