(a) Woodworm treatment: placing infested objects in a sealed enclosure and vacuum-sealing it;
(b) introducing CO2 at a controlled temperature for long enough to cover the hatching of eggs
Wood-boring insects can seriously compromise the condition of wooden artworks, affecting both the wood itself and its surface finishes and polychromy.
Insects that lay eggs inside an object (such as a sculpture, frame, canvas stretcher or painted panel) include species in the family Anobiidae; Anobium punctatum, the common furniture beetle, is a typical example. Once the eggs hatch, larvae feed on the wood, growing and excavating characteristic tunnels before developing into pupae and then adults. The adult insects then emerge through the exit holes commonly visible on the object's surface.
A treatment often used by conservators on wood,
both to address active infestation and as a preventive measure, involves colourless liquid insecticides based on permethrin, which act on larvae and adults by contact and ingestion.
They may be applied by brush, immersion, saturation, low-pressure spraying or injection.
Even after generous application in several passes, perhaps with the object enclosed in a sealed bag to enhance treatment, penetration into the wood can remain limited by the material's nature. Surface coatings such as varnish, polychromy or metal leaf can further obstruct penetration or prevent it altogether. As a result, larvae deep within the wood may not be reached. Such products also do not necessarily affect eggs, which may continue developing.
When a preventive treatment alone is insufficient, or when a different method is required for a particular object, Dorica Restauri works with specialists who provide microwave treatments against wood-boring insects and anoxic pest-eradication treatment using carbon dioxide.
