How can you easily tell if holes in items of furniture or wood are a new or an old attack of woodworm; If they are new, the holes will be clean (new-looking wood visible inside), and there will be little piles of woody dust below them if the item hasn’t been moved. If old, the holes will be dirty and very likely no dust.
If you suspect you have active woodworm it is recommended to treat with dedicated woodworm fluid, rather than general purpose timber treatment. Follow instructions on the product. Typically they say treat the area and extend treatment to a certain distand from the last visible holes