Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Upcoming Events

Spring 2021 gathering in Louisiana, April 28-May 2. Here's how to add your images.

National Moth Week 2020 photos of insects and people.

Photos of insects and people from the 2019 BugGuide Gathering in Louisiana, July 25-27

Discussion, insects and people from the 2018 gathering in Virginia, July 27-29

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Photos of insects and people from the 2014 gathering in Virginia, June 4-7.

Photos of insects and people from the 2013 gathering in Arizona, July 25-28

Photos of insects and people from the 2012 gathering in Alabama


Species Ctenolepisma longicaudatum - Gray Silverfish

Fire*brat? (We always called them silverfish.) - Ctenolepisma longicaudatum Fire*brat? (We always called them silverfish.) - Ctenolepisma longicaudatum Silverfish - Ctenolepisma longicaudatum grey silverfish - Ctenolepisma longicaudatum Very quick - Ctenolepisma longicaudatum Very quick - Ctenolepisma longicaudatum   Is this the Gray Silverfish  (Ctenolepisma longicaudata)? - Ctenolepisma longicaudatum Grey silverfish... - Ctenolepisma longicaudatum
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Zygentoma (Silverfish)
Family Lepismatidae
Genus Ctenolepisma
Species longicaudatum (Gray Silverfish)
Other Common Names
Giant Silverfish, Long-tailed Silverfish
Synonyms and other taxonomic changes
Ctenolepisma urbana

The gender of this genus is neuter, not feminine, following ICZN
Article 30, and explicitly clarified in ICZN Opinion 2427 in 2018."
body 15-19 mm
body uniformly light to dark gray; abdomen lacks median setal combs (tufts of hair) beneath but has setal combs above; rear of abdomen has two pairs of styli (fingerlike processes)
midwestern and southern United States; can be a pest in southern California
cracks and crevices in all areas of homes from basement to attic: closets, storage areas, kitchens, garages, etc.; hides during day, and avoids light
year-round indoors
paper of high chemical pulp content such as onion skin, cleansing tissue, cellophane; wheat flour and beef extract, especially when used as a paste on paper; starched clothing and dry foods
Life Cycle
female lays eggs in batches of 2-20, placing them in cracks; first instar lacks setae (hairs) and scales; scales appear in 4th instar, and genitalia appear in 14th instar; sexual maturity reached in 2-3 years; adult may molt 3-5 times per year for another 5 years
See Also
Four-lined Silverfish (formerly Ctenolepisma quadriseriata, now synonymized with C. lineata) has 4 dark lines down its back (adult image)
Common Silverfish (Lepisma saccharina) is smaller (10-12 mm) and has silvery scales but no markings
Firebrat (Thermobia domestica) is yellowish with dark brown bands and mottled spots on the dorsal surface, and is smaller (about 8 mm) and more stout-bodied (its abdomen is relatively broad-tipped and often shorter than the thorax, giving an overall "chunky" appearance)
Bristletails (order Microcoryphia) have large eyes that meet in the middle, a cylindrical body, an arched thorax, mandibles that articulate at only one point, are not normally found indoors, and have the ability to jump
Internet References
live adult image plus other info (Iziko Museums of Cape Town, South Africa)
live adult images and common name reference [Giant Silverfish] (Stephen Misfud, Wild Plants of Malta and Gozo)
live adult images (Pest and Diseases Image Library, Government of Australia)
drawing of adult; PDF doc with comparison drawings of 3 related species, and brief account of each species (Richard Houseman, U. of Missouri)
adult drawing and common name references [Gray Silverfish, Giant Silverfish] (CSIRO, Australia)
description distribution, diet (Walter Ebeling, U. of California at Riverside)
description biology, food, habitat (Augustine Exterminators, Kansas)
synonyms (Fauna Europaea)
common name reference [Long-tailed Silverfish] (Universal Protein Resource,