Silverfish and Firebrats belong to a primitive group of insects of characteristic appearance, being flattened and carrot-shaped, broad near the head end and tapering toward the rear. They are scaly and wingless and have long slender antennae. Three long slender appendages occur at the rear of the body and give this group the common name of “bristletails.” Both silverfish and firebrats develop by simple metamorphosis. Both species feed upon starches and proteins, such as fabrics, paper, starches, glue, books and other household furnishings. They leave yellowish stains, especially on linens.
Silverfish, Lepisma saccharina, are uniformly silver to brown, about ½ inch long. Silverfish females lay up to 100 eggs in cracks and crevices. Eggs hatch in two to eight weeks depending upon conditions. After three to four molts the nymphs develop adult coloration. Silverfish take three to four months to become sexually mature and may live for three to four years.
Firebrats prefer very warm areas indoors where temperatures are above 90 F. Indoors they are usually found near heating units, fireplaces, and steam or hot water pipes if these areas are not too dry. Firebrats require some moisture.
Firebrat females lay up to 50 eggs in cracks and crevices. Because of the warmth, the eggs hatch in 12-13 days. Nymphs are sexually mature in two to four months and full grown in a year. Adults may live up to two years and are mottled grayish brown, about ½ inch long.
Silverfish live in damp areas indoors or out, usually underneath boxes, boards, debris, etc. They may enter homes by being carried in on cardboard cartons, books, old papers or through house vents. They are active both day and night.
To keep silverfish and firebrats away, keep basements, laundry rooms, and bathrooms, especially shower stalls, clean and dry. Sealing holes or spaces around plumbing. Repair leaks and drips in plumbing. Clean out closets periodically, magazines, papers, and books provide food for them. Keep foods in containers with tight lids.
Registered pesticides for silverfish / firebrat control vary from state to state. There are several commercially available products that control silverfish and firebrats. In Arizona Deltadust, Borid and CY-Kick C&C Aerosol are a few available retail. Always read and follow label directions for safe use of any pesticide.
Have a silverfish or firebrat pest control question? Post it on IPCO message board.