RE: [pestlist] question about freezing
Hello Molly, Might I suggest you read the Canadian Conservation Institute (CCI) Note 3/3 Controlling Insect Pests with Low Temperature which is now available online. Figure 1 will be helpful to you in choosing the best exposure time for the temperature you can achieve. There is also helpful advice to assist you in achieving a quick cool rate which will be very important since your freezer can not reach the optimal temperature. Shannon Coles Pest Control/Collections Technician Glenbow Museum, Calgary Alberta From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Molly Gleeson Sent: Tuesday, October 14, 2008 3:58 PM To: pestlist@museumpests.net Subject: [pestlist] question about freezing I just started working for a museum that has an active webbing clothes moth infestation in their textile storage room. Half of the textiles have been packed, sealed in plastic,and are in a freezer that is set at 0 F (-17 C). We are in the process of packing the other half in preparation to move them into the freezer as well. I would like them to be frozen in a freezer set to at least -20 C, however, the freezer company quoted exhorbitant fees for lowering the temperature of the freezer, even for only a few days. I'm concerned that -17 C isn't cold enough to ensure that the moths are killed, even if we keep them in the freezer for several weeks. Is this true? I'm also thinking that weshould do a second freeze, to ensure that all life stages are killed, but if the temperature is not low enough, then maybe this is pointless. I plan to doa testby putting abag of live moths/larvae into the freezer along with the objects, to monitor what's happening, but does anyone have any experience with this, or have any suggestions aboutadjusting thetemperature and also about the recommended length of time to freeze at -17C to ensure mortality of the moths? Thanks in advance for your help, Molly Gleeson Conservator San Diego Museum of Man
RE: [pestlist] question about freezing
Hi Molly, You might also check resources on museumpests.net fact sheet on webbing clothes moth http://museumpests.net/whitesheets/default.php Fact sheet on low temperature treatment http://museumpests.net/tools/treatments/FINAL-Low_Temp_fact_sheet.pdf This fact sheet also includes references (Tom Strang's article in Collection Forum A Review of Published Temperatures for the Control of Pest Insects in Museums. Collection Forum 8, no. 2 (1992): 41-67 gives lethal low temperatures for various pests and his CCI note is very helpful as well http://www.cci-icc.gc.ca/publications/ccinotes/pdf-documents/n3-3_e.pdf What kind of a freezer are you using? You might look at this document about modifying chest freezers to get lower temperatures http://museumpests.net/resources/modifying_a_chest_freezer_for_pest_cont rol.pdf Best, Emily From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Margaret Geiss-Mooney Sent: Tuesday, October 14, 2008 7:46 PM To: pestlist@museumpests.net Cc: 'Molly Gleeson' Subject: RE: [pestlist] question about freezing Good afternoon, PestListers - My understanding of the freezing process is that freezing if done correctly also kills the eggs, very important when you are dealing with infested textiles. Check out the following NPS ConserveOGram on freezing: http://www.nps.gov/history/museum/publications/conserveogram/03-06.pdf It appears that you do need to get that freezer temperature done to -20C for 48 hours. Rapid cooling to -20C is also necessary to assure a complete kill. The ConserveOGram covers the whole procedure very well. Depending on your budget and your staffing, perhaps anoxic treatment should be considered? Regards, Meg ._ _ _ _ _ _ _ _ _ _ _ _ __ Margaret (Meg) Geiss-Mooney Textile/Costume Conservator in Private Practice in beautiful Northern California Professional Associate, AIC [EMAIL PROTECTED] ...are in a freezer that is set at 0 F (-17 C). We are in the process of packing the other half in preparation to move them into the freezer as well. I would like them to be frozen in a freezer set to at least -20 C, however, the freezer company quoted exhorbitant fees for lowering the temperature of the freezer, even for only a few days. I'm concerned that -17 C isn't cold enough to ensure that the moths are killed, even if we keep them in the freezer for several weeks. Is this true? I'm also thinking that we should do a second freeze, to ensure that all life stages are killed, but if the temperature is not low enough, then maybe this is pointless. I plan to do a test by putting a bag of live moths/larvae into the freezer along with the objects, to monitor what's happening, but does anyone have any experience with this, or have any suggestions about adjusting the temperature and also about the recommended length of time to freeze at -17C to ensure mortality of the moths? No virus found in this incoming message. Checked by AVG - http://www.avg.com Version: 8.0.173 / Virus Database: 270.8.0/1724 - Release Date: 10/14/2008 2:02 AM
Re: [pestlist] question about freezing
Hello all pest killers, Looking back in our Proceedings from 1998 I couldn´t find anything about the delayed effect of freezing, However, in our paper Bergh, J.-E., Karl.-Martin. V. Jensen,, Monika Åkerlund., Lise S. Hansen, and Martin Andrén (2006). A contribution to standards for freezing as a pest control method for museums. Collection Forum, 21 (1-2):117-125 we could show a delayed killing effect on larvae. Best wishes Jan-Erik Bergh PRE-MAL www.nrm.se/premal At 16:33 2008-10-15, you wrote: Yes, -20 deg C is considered the critical temperature. Testing on kill rates for all life cycle stages have been done by Tom Strang at the Canadian Conservation Institute (CCI) http://www.cci-icc.gc.ca/publications/ccinotes/pdf-documents/3-3_e.aspx Other research being done in Sweden has shown a significant drop in fertility rates for insect eggs that are put through the freezing process. See a review of this on line at http://www.spnhc.org/files/CF18-1_2.htm. It is the last entry -- (sorry I cannot get the link to work) PROCEEDINGS OF THE 3RD NORDIC SYMPOSIUM ON INSECT PEST CONTROL IN MUSEUMS, 1998, M. Akerlund, J. Bergh, A. Stenmark, and I. Wallenborg, eds. I am surprised to hear that the freezer company is charging higher rates for -20 deg C since most household freezers reach the critical temperature. Freezing should be done in a freezer that is not self-defrosting. Good luck! Gretchen Anderson Conservator Science Museum of Minnesota 651-221-4764 [EMAIL PROTECTED] www.smm.org - Original Message - From: Margaret Geiss-Mooney [EMAIL PROTECTED] To: pestlist@museumpests.net Cc: Molly Gleeson [EMAIL PROTECTED] Sent: Tuesday, October 14, 2008 6:46:10 PM GMT -06:00 US/Canada Central Subject: RE: [pestlist] question about freezing Good afternoon, PestListers My understanding of the freezing process is that freezing if done correctly also kills the eggs, very important when you are dealing with infested textiles. Check out the following NPS ConserveOGram on freezing: http://www.nps.gov/history/museum/publications/conserveogram/03-06.pdf It appears that you do need to get that freezer temperature done to -20C for 48 hours. Rapid cooling to -20C is also necessary to assure a complete kill. The ConserveOGram covers the whole procedure very well. Depending on your budget and your staffing, perhaps anoxic treatment should be considered? Regards, Meg ._ _ _ _ _ _ _ _ _ _ _ _ __ Margaret (Meg) Geiss-Mooney Textile/Costume Conservator in Private Practice in beautiful Northern California Professional Associate, AIC [EMAIL PROTECTED] are in a freezer that is set at 0 F (-17 C). We are in the process of packing the other half in preparation to move them into the freezer as well. I would like them to be frozen in a freezer set to at least -20 C, however, the freezer company quoted exhorbitant fees for lowering the temperature of the freezer, even for only a few days. I'm concerned that -17 C isn't cold enough to ensure that the moths are killed, even if we keep them in the freezer for several weeks. Is this true? I'm also thinking that we should do a second freeze, to ensure that all life stages are killed, but if the temperature is not low enough, then maybe this is pointless. I plan to do a test by putting a bag of live moths/larvae into the freezer along with the objects, to monitor what's happening, but does anyone have any experience with this, or have any suggestions about adjusting the temperature and also about the recommended length of time to freeze at -17C to ensure mortality of the moths? NOTE: This message was trained as non-spam. If this is wrong, please correct the training as soon as possible. Spam Not spam Forget previous vote No virus found in this incoming message. Checked by AVG - http://www.avg.com Version: 8.0.173 / Virus Database: 270.8.0/1724 - Release Date: 10/14/2008 2:02 AM
RE: [pestlist] question about freezing
This is a message from the Pest Management Database List. To post to this list send it as an email to pestlist@museumpests.net To unsubscribe look at the footer of this email. ---Return Receipt Your RE: [pestlist] question about freezing document: was[EMAIL PROTECTED] received by: at:10/15/2008 01:58:14 PM - To send an email to the list, send your msg to [EMAIL PROTECTED] To unsubscribe from this list send an email to [EMAIL PROTECTED] and in the body put: unsubscribe pestlist Any problems email [EMAIL PROTECTED]
RE: [pestlist] question about freezing
This is a message from the Pest Management Database List. To post to this list send it as an email to pestlist@museumpests.net To unsubscribe look at the footer of this email. ---Return Receipt Your RE: [pestlist] question about freezing document: wasKirsten Kvam/PORE/NPS received by: at:10/15/2008 01:17:13 PM PDT - To send an email to the list, send your msg to [EMAIL PROTECTED] To unsubscribe from this list send an email to [EMAIL PROTECTED] and in the body put: unsubscribe pestlist Any problems email [EMAIL PROTECTED]
RE: [pestlist] question about freezing
This is a message from the Pest Management Database List. To post to this list send it as an email to pestlist@museumpests.net To unsubscribe look at the footer of this email. ---Return Receipt Your RE: [pestlist] question about freezing document: wasKirsten Kvam/PORE/NPS received by: at:10/15/2008 01:43:16 PM PDT - To send an email to the list, send your msg to [EMAIL PROTECTED] To unsubscribe from this list send an email to [EMAIL PROTECTED] and in the body put: unsubscribe pestlist Any problems email [EMAIL PROTECTED]
