Integrated Pest Management
Preventing natural science specimens and material culture constructed from organic matter from being attacked and damaged by pests is a major challenge of collection management. In storage and display facilities, some of the most common pests are insects.
In the past, pest management usually involved regular applications of pesticides to collection items and areas. Health and safety concerns have led institutions to move away from this approach in favor of non-chemical preventative and protective measures. These include upgrades and repairs to building structure; installing better cabinetry; improved control of temperature and humidity in collections areas; removing food and other organic materials from collection areas; more effective monitoring; and treatment of outbreaks through freezing or anoxic environments. Using these different measures in combination is known as “integrated pest management.”
Objectives for an Institutional IPM Plan
- To develop collection management practices consistent with city, state, and federal health safety regulations
- To foster good communication with other departments responsible for ensuring the success of an IPM Plan (e.g., Facilities Operations and Custodial Services)
- To facilitate a swift and unified response to pest problems among departments with the understanding that the achievable goal is management; no policy will ever eradicate the pest problem
The first step in an IPM plan is preventing pests' access to food and hospitable harborage. Effective prevention requires determining how pests might access building and collections areas. It is equally important to understand and remove conditions that might allow them to continue to live and breed there once they enter.
Identify pests' routes of entry into the building structure, and conduits for their movement around the building once inside. Plan to mitigate these issues by, for example, repairing cracks in roofs and walls, installing sweeps and astragals to fill gaps under and between doors, ensuring that windows close tightly, sealing wall and ceiling penetrations, and providing for well-sealed cabinets that deter access to collections.
Modify conditions and behaviors that enable pests to live and breed inside the building. Pests tend to prefer areas that are dark, warm, and damp. Environmental controls can be used to maintain temperature, humidity, and lighting conditions in collections areas that are inhospitable to pests, discouraging infestations from thriving.
Good housekeeping helps prevent infestations by reducing attractants. Many of the insects which pose the greatest risks to collections can survive and breed on minute quantities of organic material. Once established, populations can move to collections storage and other nonpublic spaces. Develop housekeeping procedures that remove dust and debris that accumulates in hard-to-reach and infrequently visited areas. Keep food and food preparation away from collections. Keep collections areas clean and free of trash and debris. Avoid or carefully monitor carpets and historic furnishings that trap debris and may be highly susceptible to infestation.
Examination and Quarantine
An infested object that enters the institution can introduce pests that spread throughout your collection and building. Inspection, isolation, or monitoring of all materials brought in from outside, including circulating or loaned objects, new donations, and related packing materials is important to assure they are safe before entering collection areas.
SSolid wood packing materials (SWPM) such as crating, pallets, packing blocks, drums, cases, and skids are vulnerable to attack by wood boring insects. Because of their weight, heavy specimens (ex. paleontological field jackets, geological minerals) may be shipped using SPWM. Once inside a collection environment, those insects can cause serious damage to wooden cultural materials, specimens, furniture, and structural timbers. For institutions that transport exhibits or large collection items internationally it is essential to adhere to the legal requirements for documentation and treatment of SWPM.
All buildings have an ecosystem based on their location and other historic factors. Monitoring determines the common species in your facility, and when changing in conditions have caused a species to become a danger to collections. Traps, with or without pheromone lures or food bait, are placed throughout collection areas and checked regularly, recording the contents. Pest sightings or an uptick in pest activity should prompt an investigation into potential causes.
When pests are found in traps they must be identified. Identification provides information regarding the potential risks posed to the collection, and guides the proper course of remedial action.
The use of chemical agents in either routine pest management or in mitigating active infestations should be left to a professional pest manager trained and licensed under state regulations and health and safety standards. To deal with infestations at the specimen or collection level, the two most common procedures are low-temperature (freezing) and low oxygen (anoxia) treatments. Many large collections have been treated in the past with heavy metal pesticides and, in more modern times, with fumigants, but these do not fully protect them from infestation. Researchers must be aware of the history of pesticide and fumigant use for their safety.
IPM in Collections
Tips for keeping collections safe from pests include:
- Using inert materials for specimen storage (e.g. polyethylene foam rather than cotton wool).
- Using well-sealed storage cabinets.
- Keeping the RH low. If collections must be stored in damp environments (e.g. basements) consider micro-environments (i.e. storage cabinets) with a desiccant such as conditioned silica gel.
- Regular inspection of collections looking for evidence of an infestation, such as dead insects, larval casings, or frass (insect excrement), which often looks like sand or sawdust.
- If there is concern that coolection items are infested, isolate, inspect, and if needed, seek appropriate treatment (i.e. freezing or anoxia).
Organic Collections: Zoology and Material Culture
Zoology (vertebrate and invertebrate) collections and collections of material culture constructed from animal materials are extremely vulnerable to pest infestation. Skin, feathers, hair, dry specimens (entomology), and osteological materials containing residual fats and grease are all extremely attractive to insects and rodents. Some collections are best kept in cold storage conditions that are inhospitable to pests. If an infestation is suspected, these materials can often be safely frozen. It is important to follow proper freezing procedures to successfully kill all insect life stages. For infestations that cannot be dealt with by freezing due to size, fragility, etc. anoxia may be an acceptable alternative.
Botanical collections and material culture constructed from plant materials are less prone to infestation but are targeted by pests including silverfish, firebrats, cockroaches, various woodboring and dermestid beetles, and can provide good environments for nesting.
Inorganic Collections: Paleontology, Geology, and Material Culture
Geological materials, material culture carved from stone, made from ceramics and metals, and fossil collections are not prone to infestation. Pests can affect certain categories of paleontological material, specifically subfossil bones or mummified specimens. Pests can also feed on the adhesives used on collection items, or padding materials use in storage. There may be damage to associated items, such as labels, paper archives, or drawers and cabinets. Poor pest management may lead to these collections becoming a reservoir for pest problems elsewhere in an institution.
The website of the Museum Pests Working Group, an ad hoc group of museum professionals (collection managers, entomologists, conservators, etc), presents comprehensive resources for implementing IPM and treating infestations in museums and other cultural institutions. Resources include the PestList, a listserv for questions relating to IPM, templates for developing IPM policies and procedures, identification and treatment fact sheets, bibliographies and web resources.
The National Park Service Conserve-O-Gram series has several documents that deal with IPM including:
- Mold: Prevention of Growth in Museum Collections
- An Insect Pest Control Procedure: The Freezing Process
- Monitoring Insect Pests with Sticky Traps
- Controlling Insect Pests: Alternatives to Pesticides
- Anoxic Microenvironments: A Treatment for Pest Control
- Identifying Museum Insect Pest Damage
- Identifying Mouse and Rat Damage in Museum Collections
Combating Pests of Cultural Property by Tom Strang and Rika Kigawa of The Canadian Conservation Institute has comprehensive information on IPM.
The Canadian Conservation Institute Notes offer practical advice about issues and questions related to the care, handling, and storage of cultural objects. Relevant Notes include: