Disinfestation and conservation of entomological collections

The use of chemical products for the preservation of the collections is not always effective and very often involves health risks for those who are in close contact with the collection.

The method exposed here was suggested by the entomologists of the Natural History Museum of Milan who have experimented and adopted it since many years with excellent results.

The required equipment is a commercial freezer and the plastic envelopes for entomological boxes in which each box of the collection will be housed. The boxes are subjected to the treatment a little at a time, in the quantity allowed by the size of the freezer.

The boxes to be treated are placed in the envelops which are then closed and placed in the freezer. The envelopes prevent condensation of humidity on the outside of the boxes which would damage their coating. The treatment takes place in three phases: freezer, room temperature and freezer again. The recommended duration is two or more days for the initial phase, one day at room temperature and another two or more days in the freezer in the final phase. The interval at room temperature allows any eggs or larvae of parasites that survived the first stage to hatch, so they will then be eliminated by the second treatment in the freezer. The boxes are never removed from the envelopes where they will also be kept in the collection, thus preventing contamination by other parasites.

At the end of the treatment, the envelopes containing the boxes will be more or less covered by droplets of condensation, therefore, before placing them in the collection, it is advisable to let the condensation evaporate at room temperature.

When necessary the box can be very easily removed from the envelope, opened and put back into the envelope when the work is finished.