| |
|
|
“The principal causes of deterioration of wood are biotic (i.e. linked to organisms). These are often combined with non-biotic factors, mainly damp, that allow the organisms to develop and spread.” (G. Liotta)
Small holes with tiny piles of fine dust nearby might not seem to be a great threat to furniture and fittings, but within these holes lies the main cause of deterioration: woodworm. This is a problem which is often ignored but which must be addressed before serious restoration work can begin.
Woodworm reproduce twice a year (or even 3 or 4 times according to recent studies), and their larvae can eat away the woodwork for two to five years. Once they have become adult insects, and after making an exit hole, they take flight to reproduce and to lay their eggs in a new artefact. This kind of infestation is therefore a serious problem for the conservation of wooden furniture and fittings, and requires an effective, specific and immediate solution.
“Their habit of keeping the tunnels clear of residue provides a useful indication of an active infestation: in fact, the dust that comes out of the holes is deposited on the surfaces below forming small crater-shaped piles of a pale, flour-like material indicating both the location of the infestation and, sometimes, its extent.” (G. Liotta)
In a city like Venice furniture or beams that have been attacked by woodworm can also be affected by a parasite of the woodworm: scleroderma (Sclerodermus domesticus). This ant-like insect is a member of the Bethylidae family (as are wasps). The (rare) males are winged; the females reproduce by parthenogenesis. When they are ready to lay their eggs they enter tunnels dug by woodworm and search for host larvae which they paralyze with poison and use as food for their offspring. The female, in her search for woodworm holes, crawls around walls and can be found on curtains, sheets and fabrics. If they fail to find their normal prey, the females can sting humans – both during the day and at night – usually repeatedly, on the arms, legs, chest or back. These are extremely painful stings that are identified by a raised and reddened area of skin, diameter 12 mm, with a hemorrhagic spot and an itchy rash.
|
|
