The author is AMIGOS Preservation Service Manager (AMIGOS Bibliographic Council, Inc., 12200 Park Central Dr., Suite 500, Dallas, Texas 75251, 800/843-8482).
The Texas memorial Museum sponsored a week-long seminar on "Biodeterioration and Insect Pest Control in Collections" September 27-October 1, 1993, in Austin. As part of the seminar, lead instructor Bob Child, Head of Conservation at the National Museum of Wales, held a half-day "open session" for students and professionals on Tuesday afternoon, September 28.
At the beginning of the session, Child said he would emphasize three topics: how to set up an integrated pest management program; control methods including fumigation; and disasters and resulting infestations. He spent most of the time on the first subject.
Child said that a pest infestation can have three major detrimental effects: pests cause damage to objects, can cause damage to users (bites, etc.) and can scare users.
He asked the audience where and how pests get into a cultural institution. They named doors, "gaps" in buildings (such as windows and drains), preparatory work (especially in museums, which use insects to clean the bones of animal skeletons), disasters and storms, and educational programs (from which insects often escape) as ways which pests enter the building. Child feels that returned loans and roof spaces with nests and roosts are the two leading causes of infestations.
Attendees provided a list of insects which can infiltrate a museum. Child separated them into two main groups: nuisance pests (crickets, ants, and fleas) and those which destroy materials (silverfish, carpet beetles, roaches, moths, and psocids, which eat fabrics and/or paper).
Child suggested monitoring via four methods: collection traps near entry points; checking lights, especially ceiling lights with trays which can collect dead insects if not regularly cleared; the use of chemicals and pheromones; and "selective and nonroutine" inspection of collections looking for insects, damage, and routes of entry.
Child noted that organic materials (especially natural history collections), previously-damaged materials (including those suffering the effects of mold) and textiles are under the greatest threat. Other at-risk materials are papers and books and ethnographic materials.
Returning to his earlier comment on returned loans (and newly-accessioned materials) bringing in pests, Child suggested three steps for checking these materials: examining materials for damage upon return/entry; restricting eating and drinking in cultural institutions; and having an isolated area for examination.
The question drawing the greatest response from the audience was, "Once they get in, where do pests live?" Answers included collections, voids (under floorboards or in false ceilings), in corrugated cardboard packaging, light fixtures, HVAC systems, and trash, which Child noted was the worst offender. Simply compiling this list gave the audience a start on control measures, by giving us "target areas" to inspect. Child gave some added control suggestions here: site trash containers away from buildings; remove trash, packaging material, and unsealed or empty storage boxes regularly; eliminate or restrict eating and drinking; and clean and inspect cabinets and drawers regularly. Child said that cleaning and good housekeeping were "99% of pest control" because they remove dirt, disturb the area where insects live, and, if done regularly, give you a baseline to know when they came in.
The next portion of the class was a slide presentation, by the staff, on the flood disaster at the Texas Cooperative Wildlife Collection at Texas A&M University. Flood waters affected frozen tissues, skins, and many documentary materials. Materials were quickly freeze-dried by BMS-CAT, and while some materials show damage from the disaster, none have been infested by pests.
Bob Child next discussed control measures including fumigation and how it has developed. A portable, plastic bubble (trade names include Rentokil and Power Plastics) which can be blown up and filled with air and gasses was suggested for multiple-piece infestations. Child noted the movement to use nontoxic gasses, including carbon dioxide and nitrogen, but he noted that inert gasses will not kill mold spores, and that nontoxic methods leave no residual protection, so collections could be reinfested.
He also discussed freezing materials, suggesting that they be put into plastic bags and frozen down to -25°C for three to four days. This is a nontoxic, nonintrusive, nondamaging treatment.
Child outlined an "Insect Control Thought Process," by which librarians, archivists, and curators should ask themselves: Is the specimen alive and active; is it a pest; and will it go away of its own accord? Then, an optimum treatment can be determined.
Points to consider when treating an infestation included:
At the conclusion of the session, Child said that if treatment must be done, one should choose the safest option for people and collections. Among the top options were deep-freezing or freeze-drying, intensive cleaning, and lowering relative humidity and temperature. Many book-infesting pests have long lifespans, so Child noted that staff and administrators might be able to leave the infestation alone for a short while, while they plan a control strategy and generate money and equipment to take care of the problem.