What's Eating Your Collection?

If an object is found with damage, insect bodies, cast skins or frass and it is not clear when the damage occurred, monitoring is the key to finding out if the infestation is still active. It is important to record what has been found and this should be added to the object’s record. Remember to record the date of the find. Take a photograph of the find and date the photograph. Then remove all the insect debris and place it in a plastic bag. Keep this with the object as a record of the damage. Then clean the object. By removing all the old evidence any new damage or insect debris will be easier to spot. The object should then be monitored. Monitoring can be carried out in a number of ways.

• Look at the object on a regular basis throughout the spring and summer. Look for new damage (compare the object to the photograph), cast skins or insect bodies. If any of these are found, the infestation is active.
• The number of traps can be increased in the affected area. This can be especially useful if insect bodies have been found, but it is not clear exactly where the infestation is centred. Placing the traps in a grid pattern makes it easier to home in on the infestation. The size of the grid can be gradually decreased to locate the infestation.
• If the size of the object permits it, the suspect object can be wrapped in colourless polythene. This contains the infestation if it is present but allows one to see if cast skins, insect bodies or frass appear on or around the object. If they are seen, the infestation is active.
• Large objects can be difficult to wrap and woodborers can be reluctant to climb onto traps and thus may not be found. In these instances, laying white paper or Tyvek underneath the object will make finding frass much easier. It is important in this instance not to move the object, as this may shake frass out of the object leading to a false diagnosis.
• It may be inappropriate to place paper underneath objects on display and it is difficult to use this method for structural timber. In these cases, tissue paper (acid free) can be pasted directly onto the object using a weak adhesive such as wheat starch paste or Klucel G. If woodborers are present, they will chew holes through the tissue as they emerge. This can be a useful method of monitoring a woodborer infestation over time as the number of holes shows the number of insects tat have emerged. If this decreases, the population is likely to be dying out. If it increases, the population may be increasing and action is required to manage it.

Remember to record the RH and temperature as part of the monitoring process. This will help to determine if the infestation is active and if so, how rapidly it might progress. RH of 65%+ on a constant/prolonged basis will allow woodborers, especially Woodworm, Anobium punctatum, to thrive and temperatures above 24°C on a constant basis will allow clothes moths, Tineola bisselliella and Tinea pellionella to have more than one life cycle during a year. If an active infestation is identified, quarantine the object (see How to Quarantine) and determine an appropriate course of treatment.