Providing collection care, preservation and conservation treatment services to collectors and collecting institutions.
by Mary Ballard
I. Is Pest Control Necessary?
A pest is an unwanted organism - animal, plant, bacteria, fungus or virus.
What pest problem do you have? __________________________________
Many collection materials are not attacked by pests, but their housings may be susceptible. Also, a collection may be safe in one climate and threatened in another.
What collections are affected?
Some pest problems may bother the staff or a collection's owner, but pose no threat to artworks or artifacts. Some insects or animals are inconsequential, or even beneficial, to the home or museum environment. Finally, do not carry out pest control on a pest that does not exist!
II. Will Your Pest Control Be Effective?
What chemical or non-chemical treatment are you using?
Is the problem persisting?
Does the pest return? How often?
Where is the pest problem?
What is the original source of the pest?
What does it like to eat?
What is the pest's life cycle?
What does it need to survive? (food, light, temperature, humidity, habitat)
|A pheromone trap attracts insects, so place it at a slight distance rather than in the middle of susceptible collections; thus the bugs will be attracted away from the collection.||
Integrated pest management uses chemical and non-chemical methods to reduce and eliminate pest problems in the following steps:
(b) Cleaning. Do maintenance schedules or housekeeping policies - about food, food supplies, equipment, museum supplies, trash removal, desks and table space cleaning, flowers, indoor and outdoor plants, closets, closed spaces, floor cleaning - make the collection a better place for the pests to live?
2. Diagnosis & Reporting
Note: Some insects will not be attracted to baits or traps.
(b) Collect examples of pest damage and waste.
(c) Have an entomologist identify the pest.
(d) Learn the pest's preferred diet, life cycle and habitat.
(e) Record the location and date pests were found to determine what areas of the collection are infested.
3. Planning Pest Management
(a) Mechanical and physical control. Change your museum structure - vents, drains, screens, doors, plants or windows - to limit access. Remove plant debris and vines and bushes from exterior walls.
(b) Cultural control. Change people's work or eating habits in the galleries, offices, library and storage rooms.
(c) Sanitation. Make living in the museum more difficult for pests. Put screens on windows and caulk or block openings.
(d) Biological control. Will another organism solve the problem?
(e) Chemical control. Try local treatment, specific to the habits of the pest.
Cockroaches prefer a dark space 3/16 inch wide. They find cracks, crevices and corrugated boxes attractive.
4. Implementing Your Plan
(b) Record what you have done, the date it was done, and where it was done.
(c) Investigate any chemical you plan to use: is it legal and the least invasive or least toxic method available?
(d) Apply pest control methods properly.
(e) Know what dosage (concentration) to use and in what form (liquid, powder, oil-in-water emulsion). Do not spray chemicals on work surfaces such as desks or storage room tables.
(f) Know how long a treatment lasts at the temperature and relative humidity of your climate, and in light or dark areas.
(g) Be certain that a chemical will not affect vegetation or groundwater. Know how safe it is for humans.
5. Evaluate the Results
(b) Survey a sample of the susceptible collection. For example, look in a different cabinet every month to inspect different textiles.
III. How Toxic is a Pesticide to You?
Types of toxicity include:
(1) Acute poisoning is measured as LD50, meaning the lethal dosage for 50 percent of the animals tested. Sometimes it is measured as LC50 meaning the lethal dosage in the air for 50 percent of the animals tested. The lower the LD50 or the LC50, the more poisonous the pesticide.
(2) Chronic poisoning affects an animal or human over a long period of time after small, repeated doses. There is no widely recognized measure of chronic toxicity.
Poisons enter the body in three, measurable, ways:
(1) Dermal toxicity refers to poison absorbed through the skin. Some areas of the body are more susceptible than others.
(2) Oral toxicity refers to poison that is ingested. Pesticides on hands can be ingested while eating, drinking or smoking.
(3) Inhalation refers to poisons breathed through your nose. Breathing the vapor of the pesticide can cause harm.
A pesticide is a chemical or other agent that will destroy a pest or protect something from a pest. There are two types:
(1) A residual pesticide destroys pests and keeps them from causing damage for long periods of time after it is applied.
(2) A short-term pesticide breaks down almost immediately after application into nontoxic by-products. For example, a fumigant is a poisonous gas that kills when absorbed or inhaled. Most are highly toxic but have no residual effects.
IV. Will Pest Control Harm the Collection?
Finally, remember that what is best for one collection will not necessarily be appropriate for another.
This article has been reprinted with revisions with permission from the author and The American Institute for Conservation of Historic and Artistic Works (AIC) where it first appeared in 1997 in AIC News, 22 (3): 2-3. AIC owns the copyright of this article.