Dear colleagues,
I am trying to get some specific information about the effect of freezing on Thylodrias contractus. In the actual situation of a museum (moving collections in difficult conditions, chest freezer of the museum overloaded) the institution planed to rent a freezer truck for treating a part of the collection. It seems that there will be no way to reach at least the temperature of -25°C in the available freezer truck, only -20°C. It was planed to treat one week at -20°C. I am concerned about this short time of treatment at on only 20°C and I have doubts about the effectiveness, especially because eggs of Thylodrias contractus could be present. I would rather recommend, if lower temperatures cannot be applied, two-three weeks of treatment in order to compensate for the higher temperature. My doubts are reinforced by the experience of the Herbarium of the Academy of Natural Sciences in Philadelphia *: after treatment at -20° C for one week, larvae of Thylodrias were found (the targed beetle was the cigarette beetle); the cold was suspected to act as a natural trigger for the hatching of the eggs. -Has anyone studied the effect of freezing on Thylodrias contractus at different stages, different temperatures and different time of treatment? - Does any museum or institution noticed the reappearance of Thylodrias after freezing at only 20°C? * 2004. Lesson in Integrated Pest Management (IPM): the herbarium of the Academy of Natural Sciences, Philadelphia. Society for Preservation of Natural History Collections (SPNHC). Sasha Eisenmann, James Macklin and Lucinda MC Dade, Department of Botany ANPS, Philadelphia. Poster presentation. Annual Meeting, NewYork city. Thank you in advance for any information Michaela Berner Biologist Consultant 14, rue Mayet 75006 Paris France tel: 00 33 /(0)1 44 49 99 81
