Mary -

That's a great point.  Insects do not chew through a bag in order to lay eggs; 
however, larvae will certainly chew their way out of a bag.  I've seen it with 
cigarette beetle larvae, Anobium punctatum (furniture beetle larvae in books), 
Indian meal moth and webbing clothes moth larvae, and carpet beetle larvae.  
Emerging powderpost beetle adults do not seem to be able to chew their way out 
of a polyethylene bag.  Adult webbing clothes moths do not even have functional 
mouthparts for chewing into a bag.  Carpet beetles do, but I've never seen a 
situation where they have chewed into a bag.

Tom Parker 


-----Original Message-----
From: Mary Baughman <m.c.boff...@mail.utexas.edu>
To: pestlist@museumpests.net
Sent: Wed, 10 Jun 2009 6:12 pm
Subject: Re: [pestlist] Wrapping infested objects for freezing



Greetings -




I have just one observation to add:




One Friday afternoon we wrapped a book collection in 3 mil thick plastic 
sheeting.

Each book was individually wrapped; the plastic was wrapped closely around the 
book to eliminate air space.

The truck to transport the large collection to a commercial freezer was 
scheduled to arrive early Monday morning.......




Monday morning we observed tiny holes bored through the plastic by the 
"drugstore beetles"

(Stegobium paniceum) that we were attempting to exterminate.




I assume that the atmosphere inside the books that had been sealed in the 
plastic was a little too stuffy for the insects.




Mary Bau
ghman
Book Conservator
Harry Ransom Humanities Research Center
The University of Texas at Austin
P.O.Drawer 7219
Austin, Texas  78713-7219

Telephone (512) 471-8635 or 471-9117
Fax (512) 471-7930











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Hi Alyssa,


Responding to your points:
1. To contain infestation while transporting specimen to the freezer
(Essential as it prevents spread, there may be quarantine time needed until
the freezer can be unloaded and the next load run through. yes, damage
continues in the bag at room temperature, but the overall level of control
of the crisis is greatly improved. I have several examples of large scale
pest treatments being sabotaged by poor quarantine during this phase.)



2. To prevent moisture content changes in the object during freezing, which
could result in dimensional changes and physical damage (Essential, as it
definitely does that by imposing a self-buffering regime)


3. To prevent damage from possible freezer failure (water drips/ floods,
debris from ceiling)  (Essential as freezers *do fail*, and the
consequences are catastrophic if objects are not bagged, and the
consequences are more likely the more the freezer is used justifying its
purchase)



4. To prevent condensation from forming during its acclimatization before
the bag is opened  (Ess
ential for objects with surfaces likely to be
affected by condensation)



5. To prevent (or slow) re-infestation during acclimatization (Arguably
necessary. Tom Parker made a good point on the low reinfestation likelyhood
in the short term provided the acclimation place is not crawling. The point
I make is if you are reintroducing to collection, a reasonable use of the
bag you paid for in labour and material cost is a continued assurance of
protecting the object until the residual pest problem is solved (roving
critters, local sanitation, seal detail improvements etc). In dealing with
larger infestation problems, the acclimation space may only be in the
original resting space which you treat by residual spray, sanitation before
reintroduction of objects etc, in which case the bag is essential to reduce
contamination from the lower but still evident risk of reinfestation until
enough time has passed your trapping and inspection protocol lower your
evaluation of threat). Commonly the bag protects your investment in time
and labour - it does not represent a net loss in time and labour.


I am however interested in the discussion on necessity. In the thermal
treatment of some types of collections, taped coated cardboard boxes are
arguably sufficient for highly buffered, low mechanical risk objects, as
they act as a moisture barrier/buffer in the temperature transition phase.
We have used them in botany collection experiments and practices. But -
people then rely 100% on the freezer warning system  and rapid staff
response
 should a breakdown occur.


Of course, sealable plastic containers are great, and are beautifully
matched to collections like natural history where size distributions are
dominated by handfuls to arm-sized specimens.



In general, the stipulation of the use of polyethylene bags is a wise one,
as failure occurs in batches in the freezer, not individual items. The
bigger the load, the greater the risk. The primary issue is reducing labour
and wastage costs through adopting reusables to handle common sizes.


Sincerely,
Tom Strang

Canadian Conservation Institute | Institut canadien de conservation
Senior Conservation Scientist | Scientifique principal en conservation
Institut Canadien de Conservation | Canadian Conservation Institute
Ottawa, Ontario, Canada, K1A 0M5

tom.str...@pch.gc.ca
Téléphone | Telephone 613-998-3721 (extension 239)
Télécopieur | Facsimile 613-998-4721
Téléimprimeur (sans frais) 1-888-997-3123 | Teletypewriter (toll-free)
1-888-997-3123





                                                                      
             "Becker, Alyssa                                       
   
             TPCS"                                                    
             <alyssa.bec...@go                                          To
             v.sk.ca>                  <pestlist@museumpests.net>     
             Sent by:                                                   cc
             pestlist-ow...@mu                                        
             seumpests.net                                     
    Subject
                                       [pestlist]  Wrapping infested  
                                       objects for freezing           
             06/03/2009 06:51                                         
             PM                                                       
                                                                      
                                      A
0                               
             Please respond to                                        
             pestl...@museumpe                                        
                  sts.net                                             
                                                                      
                                                              
       







Hello,


Here at the Royal Saskatchewan Museum I wrap anything to be treated for
insect pest infestation in polyethylene plastic prior to freezing. These
objects are most often natural history specimens (mounts) and textiles or
leather/hide/feathered objects from our Aboriginal History collection.


Lately this practise has come into question - is it not a waste of time and
resources to do this, especially since much of the plastic must be thrown
away to prevent possible cross-contamination? Could the wrapping stage be
eliminated for adsorbent objects in good condition?


My reasons to continue wrapping are listed below. However, I wanted to pose
these questions to the list for thoughts, from a practical point of view,
as to whether wrapping is important, and if so, how and when. Has anyone
has come up with a more environmental alternative? For example, has anyone
found a line of vapour -proof, washable tubs that would do the same job for
a variety of sizes of mounts?


Reasons for wrapping:
1. To contain infestation while transporting specimen to the freezer
2. To prevent moisture content changes in the object during freezing, which
could result in dimensional changes and physical damage


3. To prevent damage from possible freezer failure (water drips/ floods,
debris from ceiling)
4. To prevent condensation from forming during its acclimatization before
the bag is opened
5. To prevent (or slow) re-infestation during acclimatization


Your thoughts and ideas on
 the subject would be most appreciated!


Sincerely,


Alyssa Becker
Conservator
Royal Saskatchewan Museum
2340 Albert Street
Regina, Saskatchewan  S4P 2V7
P: 306-787-2667  F: 306-787-2645
alyssa.bec...@gov.sk.ca





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