Common Name: Silverfish, Bristletail
Scientific Name: Various
Class/Order/Family: Insecta/Thysanura/Lepismatidae
Metamorphosis: No Metamorphosis
Introduction: All members of the order Thysanura have a teardrop/carrot/fish-shaped body and get their common name of bristletail because of their 3 long, bristlelike or taillike appendages on the posterior/rear end of their body. Silverfish is a common name for species of this group whose bodies are covered with silvery scales. Silverfish are found throughout the United States and the world.
Recognition: Adult body length, not including tails, about 1/2-3/4" (12-19 mm). Wingless with flattened body. Shape teardrop/carrot/fishlike, tapering from head to rear, and generally covered with scales. Color silvery to gun metal, 1 species with dark lines running length of body. Antennae long, threadlike. Posterior end of abdomen with 3 long, bristlelike appendages (2 cerci, 1 median caudal filament). In addition, compound eyes small, widely separated; ocelli absent; coxae lack styli (fingerlike processes); tarsi 3- or 4-segmented; some abdominal segments with a pair of styli; abdominal sternites (underside of segment) lack median setal combs (tufts of hair) or if present, last abdominal tergite (upper side of segment) longer than wide; abdominal tergites with outer dorsal setal combs (tufts of hair) or if lacking, last abdominal tergite longer than wide.

Immatures similar to adults in appearance, except for size. Scales appear with 3rd or 4th molt.