Book Bugs in Colorado

by Sharon Partridge for the Colorado Preservation Alliance

Colorado is fortunate not to have the kind of insect infestations found in humid, warmer climates but even its repositories can house unwanted guests. Insects are frequently “invited” into the library or record center by the food crumbs left in areas where eating is allowed or, as we all know, by the munchers who eat even when anti-food rules are strictly enforced. Once the real food is gone, insects will turn to books and paper. The following is a list of insects which will cause damage, the┬átypes of damage that can be found, and how to eradicate your unwelcome visitors.

Cockroaches are the most difficult insect to control. They have a large, flat, oval body; hairy legs; and very long, slender antennae. They prefer damp, dark places and can move very quickly. They leave brown stains on paper. Good housekeeping is absolutely vital to their control. Remove all potential food and water sources and institute frequent dusting and vacuuming. Boric acid will kill cockroaches but is harmful to children and pets. Colorado State University’s Cooperative Extension has produced an outstanding publication, “Household Insects of the Rocky Mountains” that contains abundant detail on their elimination.

Silverfish are carrot shaped, silvery, and have what look like antennae on both ends. They are fond of living under boxes, boards and furniture. They are the most destructive insect since they eat the starch used to size coated papers, the paste used to bind the book, and the ink off the page. Missing letters and holes in paper are evidence of silverfish. Silverfish control is much like the steps needed if cockroaches are present.

Firebrats look almost exactly like silverfish except for their mottled color. They prefer heat and will be found around furnaces and heating units. They cause the same damage and require the same treatment as silverfish.

Crickets will usually only be a problem when heavy rains follow a protracted drought. These conditions cause swarming and swarming crickets will eat almost anything; plastic, wood, paper, leather, and fabric.

Termites look like small white ants. While termites are not a major problem in Colorado, the subterranean species does occur, particularly around landscaped areas with their higher humidity. Termites live on cellulose, the primary source of paper. They will eat the cover and pages in long, wiggly tracks that look almost like a engraved Jackson Pollack painting. Heat and dry conditions will discourage termites but they do require professional treatment with insecticides. Some building modifications can eliminate any future infestations. CSU’s publication goes into great detail on the type of modifications to consider.

Prevention is the best pest control. A no-food policy that is strictly enforced, a frequent cleaning schedule, and elimination of damp, dark areas will all be major weapons against bugs. To avoid importing any problems, SOLINET recommends putting any new donations into white kitchen bags for a few days to make detection of eggs, insects and leavings easier. Sticky traps in untraveled areas can alert you to problems that might have been undetected and early treatment is much easier than reacting to a major population.

Insecticide is not a first choice since the chemicals may cause as much damage as the insects but in a few cases (particularly termites) there is no alternative.

If just a few books are affected and they are not of unusual materials such as wood, the books can be frozen in a food-free freezer capable of temperatures below -10 degrees Fahrenheit (-20 degrees C). Frost-free freezers are not a good choice because they do not maintain a constant temperature. e sure you wrap each book in heavy-duty plastic and squeeze out as much air as possible to prevent moisture from reaching the book. Freeze for at least 72 hours (longer is better) and it may be necessary to repeat the process several times. Thaw the books slowly (perhaps in a refrigerator) and leave them wrapped for several more weeks to allow detection of any resurrection. Holes in the plastic would indicate an escape.

Insects can be controlled in any repository but only through prevention and knowing your enemy. Be prepared to take whatever steps are necessary as soon as you are aware of a problem and stay alert.


Baughman, Mary. Letter from University of Texas at Austin dated December 1994.

Colorado State University, University of Wyoming, and Montana State University. “Household Insects of the Rocky Mountain States,” Bulletin 557A. 1994.

Hickman, Norman. “Bookworms: the Insect Pests of Books.” London: Sheppard Press, 1985.

Tusa, Bobs. “Integrated Pest Management: Beating the Critter Jitters.” “Southwestern Archivist” 18 (Summer 1994): 42-43.