How much damage do silverfish do to library books?

I once opened the pages of an old copy of Richard Dawkins' "The Extended Phenotype" in a library, and there was a dead silverfish in between the pages of a book...

InquilineKea

preservation

Comments

Ashley Nunn: This is asking two questions at once, one of which is going to change pretty rapidly and is pretty hard to keep track of - I would suggest taking out the second question, and perhaps making the actual body of the question a bit more detailed, with something other than the personal anecdote.

Answer by Ashley Nunn

It really depends on how large the infestation is, and how long it has been going on.

Damage to paper products from silverfish is caused by their direct feeding on the materials. The feeding of silverfish results in irregular feeding areas that exhibit characteristic "thin spots" Silverfish do not have strong chewing mouth parts and therefore tend to sit on the surface of the paper and gradually abrade the surface. In some areas of the damage, the feeding will result in irregular holes in the paper. In other areas, however, the feeding will not break entirely through the paper and will result in thin spots or simply the removal of the printed word.

When silverfish feed on printed materials, they often leave a fine, pelletized frass (excrement) which is black and resembles a miniature mouse dropping. Under magnification, this residue is fairly easily distinguished as individual pellets or droppings. This material accumulates under items or may be scattered randomly over surfaces in darkened areas. It may also be found on the interior of acid-free storage boxes. Large amounts of frass may be found in attics insulated with cellulose insulation (ground up newsprint).

They prefer moist, dark environments, so ensuring that they don't have that kind of environment to thrive in will go a long way to ensuring the safety of the books and other materials. This article speaks mainly of silverfish in houses, not libraries, but the advice holds.

Silverfish are usually introduced into houses from an outside source. Prevention of silverfish infestations should begin with sanitation. Vacuum cracks and crevices to remove dust and lint. Keep bookcases clean by vacuuming and shaking out books. Don’t allow piles of old papers and magazines to accumulate. Check old bks before bringing them into the house. Store starched linens in sealed plastic bags. Seal cracks and crevices with caulking compound to reduce the number of hiding places. Make the environment less attractive by reducing the humidity with a dehumidifier. Anhydrous calcium carbonate, a dehydrating agent, is effective in removing moisture from the air in closets and other small spaces.

There are also chemical solutions to silverfish problems, but those can also harm the books and other materials - these solutions are best left to people with more expertise in these things, especially where a library collection is concerned.