Session 2: The Building and Environment

pest management

1 Preventing Pest Infestation | 2 Responding to Pest Infestation

exppest_spilled
Allowing food and drink in the vicinity of collections is not recommended, since it can
attract pests and result in accidental damage.

Controlling pest activity in your collections is most effective when it targets the source of the problem, e.g. the conditions that allow pests to enter and infect a facility. This strategy emphasizes ongoing maintenance and housekeeping to ensure that pests will not find a hospitable environment. Maintaining a moderate climate is also an important tool in preventing pest infestations.

The most common insects that affect paper-based collections are silverfish and firebrats, psocids (booklice), and cockroaches. Many insects are attracted to dark, small, seldom-disturbed spaces, where significant damage can be done before the problem is discovered.

Most insects are not attracted to paper itself, but rather to sizing, adhesives, and starches. However, some insects will attack cellulose (paper and cardboard), as well as protein (parchment and leather). Insect damage is caused not just by eating, but also by tunneling, nesting, and bodily secretions.

Rats, mice, squirrels, birds, and other small animals can also cause significant damage to paper collections. Rodents especially are attracted to environments that are dark, wet, dirty, cluttered, and undisturbed.

1 Preventing Pest Infestation

Integrated pest management strategies are best practices in cultural heritage collections that focus on improving building and storage conditions to prevent insects from settling into an institution. Tactics include blocking routes for pests to enter the building (such as windows, vents, and cracks), maintaining a moderate climate, avoiding water leakage or standing water, removing or controlling food sources, and housekeeping practices like dusting, vacuuming, and garbage removal. Inspecting incoming collections for evidence of pests, as well as performing regular building inspections to look for signs of insect evidence like droppings or bodies, are long-term responsibilities to prevent against infestation.

The use of pesticides to prevent pests and respond to infestations has been common in cultural institutions, but preservation professionals now recommend a strategy called integrated pest management (IPM). IPM relies on non-chemical methods to prevent and manage pest infestation.

2 Responding to Pest Infestation

Monitoring

exppest_sticky

Sticky traps such as this one can help to determine the number and type of insects in a specific area.

If a few insects are observed in the building, monitor the situation with sticky traps (available in hardware and grocery stores) to determine the type of insect(s), the number of insects, and their entry points. Place traps in consistent locations, number and date them, and inspect them routinely. Traps that are unchecked don't provide any useful data, and may become food sources for other pests if left undisturbed for long periods of time. If results are negative, relocate the traps. Once insects have been trapped, identify them to determine what threat they pose to collections.

In cases where there is a serious insect infestation that does not respond to preventive techniques, direct treatment for insect infestation may be necessary.

Non-chemical Treatments

Controlled freezing of infected collections, along with modified atmospheres have been used successfully to eradicate pests in cultural collections. Controlled freezing can be done in household or commercial freezers, blast freezers, or freezers with controlled temperature and humidity. Modified atmospheres (decreased oxygen, increased carbon dioxide, or use of an inert gas such as nitrogen) can be applied in a fumigation chamber or bubble, or in low-permeability plastic bags. Specific procedures must be followed for both methods; see the NEDCC Preservation Leaflet Integrated Pest Management for details.

Heat, gamma radiation, and microwaves are used for insect control in food processing and other industries, but are not recommended for cultural collections due to their damaging effects on collections.

Chemical Treatments

Current preservation practice does not recommend extermination (chemical treatments) for pest problems except as a last resort, due to the toxic nature of pesticides.