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Dealing
with Infested Items Most museums have moved away from the use of
chemicals to control or kill infestations in collections because chemicals
have been found to harm people as well as the objects. The current guiding
principle to which many museums adhere is called integrated pest
management, or IMP for short. Originally developed for agriculture,
IPM utilizes physical, mechanical, cultural, biological and educational
methods to eliminate infestations. Chemicals are used as a last resort.
If You Have an Infested
Item
MNA freezes its infested objects, but it is not advised that all items be
frozen. Composite objects, such as kachina dolls, could be damaged by the
freezing process. It is recommended that a professional conservator be
consulted. Other items, such as rugs and baskets, can be safely frozen,
but when in doubt, contact a professional conservator.
If you feel that an item is stable enough to be frozen follow these steps:
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Procedure
1.
Seal the item in a clear plastic bag so that you can see it. To
prevent moisture condensation, try to squeeze out as much air as possible
before sealing the bag with a twist-tie, rubber band, or other means.
You can also use Ziplock bags.
2.
Place the item in a freezer that is not fully loaded, is set at its
coldest setting, and has been running for at least 24 hours. It is
better if the freezer is empty. The best type of freezer to use for this
purpose is a chest freezer, because the cold air will not flow out like it
will in an upright freezer. But a problem with a chest freezer is that the
bottom often stays fairly warm (32°F), so place a rack or empty box in the
bottom to elevate the infested item.
3. Freeze the item for at least
48 hours. Ideally, the freezer should achieve and maintain a temperature
of at least minus 4°F during this time. You can use an inexpensive
indoor-outdoor thermometer to track the temperature in the freezer.
4.
Remove the item and let it thaw for at least 24 hours. Scientists believe
this step “fools” hardy insects into believing that spring has arrived.
5. Repeat step
3.
6. Remove the item, let it
thaw, and then carefully vacuum the piece to remove any bug residue.
Monitor the item for a few months to see if any new infestation occurs. If
it does, follow the freezing procedure above.
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One other item to note: Canadian conservators have reported
that a longer freezes of five or more days is more effective than a
shorter freeze, and they do not refreeze the infested item a second time.
To be safe, you might prefer a longer freeze that includes a second
freeze.
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Special Notes
If you want to get an unfamiliar insect identified: The
University of Arizona probably has has a department that will
identify “bugs” at no cost. Each state probably has one of these
departments.
For an “ID” form, contact:
Insect Identification Service
Department of Entomology
College of Agriculture
University of Arizona
Tucson, AZ 85721
520-621-1151
If you want to know more about pest control, Common Sense Pest
Control: Least Toxic Solutions for Your Home, Garden, Pets
and Community by William and Helga Olkowski and Sheila Daar, 1994,
is a good reference book. The book provides guidance and advice for using
both non-chemical and chemical (pesticide) treatments.
Published by Taunton Press, Inc. (63 South Main Street, Box 5506, Newtown,
CT 06740-5506, ISBN 0-942391-63-2), it is available with a hardback
cover and contains 736 pages, 308 drawings and 107 tables and charts. It’s
priced at around $40 - $45. Barnes and Noble has carried this book in the
Home Improvement section, otherwise, contact your local bookstore for more
information about how to order a copy.
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