Silverfish: Summertime Pests
Silverfish, and their close relatives, Firebrats, are small, wingless, teardrop-shaped insects generally covered with (respectively) grayish or brownish scales. They have long, thin antennae and long, thin bristle-like appendages at their tail end. They hide in cracks during the daytime and become active after dark. Most of them feed on starches, sugars, and proteins they can get from book bindings, glazed paper, or similar sources, including dead insects. They require high relative humidity (usually 70-90%) to live. Silverfish survive best at 70-85 F; firebrats survive best at 90-106 F. Individuals may live 2-8+ years. Some species can digest cellulose and some are cannibalistic. They may severely damage older books, papers, or other sweet or starchy materials in warm, moist, dark areas. They are often introduced into a home within cardboard or other paper products. Effective control requires correct identification, surveillance, drying out the infested area(s) to below 65% relative humidity, possibly physical removal by vacuuming, and treatment with a properly labeled residual chemical. Dust or wettable powder formulations should work well for silverfish. Inorganic dusts or microencapsulated formulations may give better long-term control of firebrats because they hold up better at higher temperatures in which these pests are normally found.