In 1986, Mary-Lou E. Florian published "The Freezing Process- Effects on Insects and Artifact Materials: A literature review and recommended procedures for freezing insect infested artifacts for insect eradication" (Leather Conservation News, Vol. 3, No. 1, Fall 1986). In that comprehensive article, she gave a number of general recommendations based on a wide ranging review of available literature that would be applicable to household and museum pests. In the conclusions and synthesis section of the article, she recommends a relatively quick reduction in temperature to shock the insects and prevent the 'anti-freeze' effect, a gradual thawing or into a refrigerator to thaw, and that "it is desirable to immediately repeat the freeze-thaw cycle". That recommendation became known as the "double-reduction method".
Unfortunately, the Leather Conservation News is not available on-line. If you have questions, please contact me off-list. Thanks, Paul On Fri, May 3, 2019 at 11:01 AM Todd Holmberg <[email protected]> wrote: > For the group that believes a second freezing is necessary, is it because > of how some insects can apparently create some sort of internal antifreeze > like material that can allow them to come back to life after being frozen? > The second freeze then kind of "catches them by surprise" in a way as > they are unthawing thinking "winter is over". (Is that the general theory?) > > I have been told that as long as the freezer temp is already at -30 when > the object is placed inside, the rate that the object cools down is rapid > enough to prevent insects from protecting themselves with the antifreeze. > > Hypothetically, if you are freezing wood that is pretty thick/dense, and > wood boring beetles had burrowed deep into the object near the > center, could the thickness of the wood give those insects near the > center a little extra time to protect themselves? Would this type of > scenario benefit from a "double freeze"? > > -Todd > > On Fri, May 3, 2019 at 9:29 AM Voron, Joel <[email protected]> wrote: > >> At -30 for 72 hours once is sufficient to kill all life stages of pests. >> JTV >> >> >> >> >> >> Joel Voron Colonial Williamsburg Foundation >> >> Conservation Dept. >> >> Integrated Pest Management >> >> Office 757-220-7080 >> >> Cell 757-634-1175 >> >> E-Mail [email protected] >> >> >> >> >> >> >> On May 3, 2019, at 8:52 AM, Adrian Doyle <[email protected]> >> wrote: >> >> Dear all >> >> Double freezing shouldn’t be necessary so long as the core temperature of >> the object is at the correct temperature for the correct time >> >> Adie >> >> >> >> Mr Adrian (Adie) Doyle >> >> Integrated Pest Management Manager >> >> British Museum >> >> Property & Facilities Management >> >> Great Russell Street, >> >> London WC1B 3DG >> >> >> >> Tel: 020 7323 8207 >> >> Mobile 07813 363292 >> >> Also available by Radio >> >> >> >> Email: [email protected] >> >> >> >> *The British Museum* >> >> Great Russell Street, London WC1B 3DG >> >> britishmuseum.org <http://www.britishmuseum.org/> >> >> >> >> *The security classification for this message is OFFICIAL* >> >> >> >> >> >> >> >> >> >> *From:* [email protected] [mailto:[email protected] >> <[email protected]>] *On Behalf Of *Sharon Penton >> *Sent:* 03 May 2019 13:51 >> *To:* [email protected] >> *Subject:* [pestlist] Freeze once or freeze twice? >> >> >> >> Good morning all, >> >> >> >> Some of my colleagues are adamant about freezing collection twice when >> dealing with pest. They freeze a first time then let everything get back to >> room temperature for a day or so then freeze again. Is this common >> practice? I've always thought if we can achieve a reliable -30 that should >> take care of all adults larvae and eggs? >> >> Would someone mind weighing in? >> >> Thanks! >> >> Sharon >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Museumpests" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at https://groups.google.com/group/pestlist. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/pestlist/CALWceqtcq04tuBmBQP0uvpFfmNezUsXoCdFkWH4YMc%3DDYTP3KQ%40mail.gmail.com >> <https://groups.google.com/d/msgid/pestlist/CALWceqtcq04tuBmBQP0uvpFfmNezUsXoCdFkWH4YMc%3DDYTP3KQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Museumpests" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at https://groups.google.com/group/pestlist. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/pestlist/DB6PR0201MB238959630E1D44BF3297289EDD350%40DB6PR0201MB2389.eurprd02.prod.outlook.com >> <https://groups.google.com/d/msgid/pestlist/DB6PR0201MB238959630E1D44BF3297289EDD350%40DB6PR0201MB2389.eurprd02.prod.outlook.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Museumpests" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> Visit this group at https://groups.google.com/group/pestlist. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/pestlist/9C51E7E8-C337-46D1-BE8C-A7CF7F7220DE%40cwf.org >> <https://groups.google.com/d/msgid/pestlist/9C51E7E8-C337-46D1-BE8C-A7CF7F7220DE%40cwf.org?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > -- > You received this message because you are subscribed to the Google Groups > "Museumpests" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/pestlist. > To view this discussion on the web visit > https://groups.google.com/d/msgid/pestlist/CAMxAh%2BgsmkWXSMXcUqf6yDpe15ikTX2Kg1oxUodbU5xykxbXFQ%40mail.gmail.com > <https://groups.google.com/d/msgid/pestlist/CAMxAh%2BgsmkWXSMXcUqf6yDpe15ikTX2Kg1oxUodbU5xykxbXFQ%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- *Paul S. Storch* *Collections and Exhibits Liaison - Historic Properties* Project Specialist III Facilities- Historic Properties Unit Facilities and Risk Management Department Administrative Division Minnesota Historical Society 345 Kellogg Blvd. West <https://maps.google.com/?q=345+Kellogg+Blvd.+WestSaint+Paul,+MN+55102&entry=gmail&source=g> Saint Paul, MN 55102 <https://maps.google.com/?q=345+Kellogg+Blvd.+WestSaint+Paul,+MN+55102&entry=gmail&source=g> -1906 (651) 259-3257 [email protected] *Visit Historic Sites!* www.mnhs.org *OUR CULTURE:* *- Respect* *- Collaboration* *- Innovation* *- One MNHS* -- You received this message because you are subscribed to the Google Groups "Museumpests" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/pestlist. To view this discussion on the web visit https://groups.google.com/d/msgid/pestlist/CAGGymYJ5Uy0-RS93E%3DogzsutWyZYEGUGxTwomAG%2Bnkz%2BsB_ekw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
