While they may not elicit the same loathing as cockroaches do, silverfish can cause considerable damage. These small, silver-gray insects eat cellulose, a starchy component commonly found in items such as paper, wallpaper paste and flour. As a result, silverfish can destroy books by eating the paper and binding, cause wallpaper to loosen from the wall and contaminate stored foods such as flour and pasta. According to the University of California Statewide Integrated Pest Management Program, most commercial insecticides have not been fully tested on silverfish. Fortunately, silverfish are susceptible to other methods of extermination.
Place an infested book inside a microwave oven and microwave on high for 30 to 60 seconds. This method can sometimes harm books, so do not microwave valuable books, fragile books or books with color plates. After treatment, shake the book over a garbage can to dispose of dead silverfish.
Wrap masking tape around the outside of small glass jars, with the sticky side of the tape facing out. Place the jars in the corners of areas where there is silverfish activity or evidence of silverfish. The insects use the masking tape to crawl up the jar; once they fall into the jar, they are unable to crawl back out. Flush the captured silverfish down the toilet.
Spray liquid pyrethrin into the cracks and crevices around doors, windows and baseboards. This method will only kill silverfish present at the time of spraying, as pyrethrin kills silverfish on contact but has little residual action.
Fasten a disposable face mask in place over your mouth and nose. Follow the insecticide bulb duster's directions to fill the bulb with either diatomaceous earth or boric acid.
Squirt the powder into likely silverfish hiding places. This includes cracks and crevices around doors, windows and baseboards, as well as the rear of shelves and bookcases. Both diatomaceous earth and boric acid are effective indefinitely against silverfish, so leave the powder in place to kill both adult silverfish and hatching nymphs. Do not use this method in wet areas because moisture causes these powders to cake and lose their effectiveness. If you're using either of these powders after spraying with pyrethrin, wait until the pyrethrin is dry before using these powders in the same area.