The only thing worse than mice or cockroaches feeding on breadcrumbs in your kitchen is finding them munching on invaluable paintings and artifacts in your museum or library. Insect pests are responsible for significant damage to museum objects, historic books, and in buildings of historical or architectural importance. Various wood-boring beetles, various moths, and booklice can destroy materials, objects, and building parts. Termites, cockroaches, and other insect pests are also common in museums and libraries, and their presence results in even greater damage of wood and paper materials.

Insects do not infest all items in equal ways, however. At the highest risk of infestation are natural history collections, dried insect collections, dry plant materials, stuffed animals, items containing fur, and keratin or chitin-based materials. Usually, items made from these vulnerable materials are stored together in dark areas, making the spread of infestation easier and more successful.

In the past, pest control in such collection-holding institutions involved regular applications of insecticides to the infested areas and to the objects themselves. Recent health and safety concerns, however, have convinced many institutions to move away from spraying toxic chemicals in favor of a combination of proactive and preventative measures collectively known as Integrated Pest Management (IPM).

Rather than just treating the existing infestation over and over again, IPM is focused identifying risk conditions, locating access points, and providing feasible mitigation strategies that are both safe and effective. Here are some of the most successful control methods currently used in museums and libraries to eliminate insect infestations.

Isolation. Although isolation of contaminated items is not an IPM treatment per se, this method can be used to indicate the presence of an active infestation, which is a crucial part of any IPM plan. Isolating, inspecting, and cleaning items entering the institution helps avoid granting pests access to the rest of the collection and building.

Freezing. Freezing, also known as controlled low-temperature treatment, is a common pest management and inspection method in museums. Not all items can be frozen, however; the ones that can undergo this treatment and sustain no damage include:

• Oil and acrylic paintings
• Photographic materials
• Audio-visual items such as tapes, discs, cassettes, VHS, glass archival materials, and others

Freezing is also carried out by some museums as a preventative measure whenever collections are moved into a new facility or if bulk collections that cannot be individually inspected are acquired.

Baiting. A lot of museums use baiting systems, typically using a nontoxic material, to instigate large-scale consumption within the pest population. When insect workers are seen feeding, the original nontoxic bait is replaced with bait containing a slow-acting insect growth regulator that ends up disrupting the breeding cycle of the colony. As the worker population is reduced, the colony soon starts collapsing and die. This method is particularly successful at eradicating subterranean termites and is used as a safer treatment option because it eliminates poisoning of non-target insects.

Heat treatment. Heat treatment for infested artifacts is perhaps the most effective method for ensuring 100% efficacy in eradicating insect pests. Museum managers prefer this method for treating both small individual objects and entire multi-story buildings. It is inexpensive compared to other treatments, easy to conduct, and can be applied to a variety of objects.

Gas treatment. The use of atmospheric gases such as nitrogen or argon gas in sealed enclosures to eradicate insect infestation of museum objects is another effective alternative to toxic substances. This method works by introducing gases that reduce the oxygen levels in an infested area to 0.1%, which interferes with the glucose production of insect pests, resulting in weight loss and eventually death. Almost all art objects can be treated with this method.

The application of most methods of treatment used to eradicate insect pests in museums, whether chemical or fumigant, require training and licensing. It is essential to work with a knowledgeable and experienced pest management professional to make sure that all legal and safety regulations are met. Establishing a working relationship with a reputable commercial pest control company in your area will also guarantee prevention of future infestations and ensure the safety of invaluable exhibit items.

About the Author

Daniel Mackie, co-owner of Greenleaf Pest Control, is a Toronto pest control expert well-known as an industry go-to guy, an innovator of safe, effective pest control solutions, and is a regular guest on HGTV. Mackie, along with business partner Sandy Costa, were the first pest control professionals in Canada to use detection dogs and thermal remediation for the successful eradication of bed bugs. In his free time, he is an avid gardener.