Silverfish belong to the insect order, Lepismatidae and can be found throughout the United States. This order is characterized by three long tail-like appendages arising from the tip of the abdomen. The silverfish gets its name from its silvery color and the fact that it resembles a fish. This insect has chewing mouthparts, long antennae, and their body is nearly always covered in scales.
Silverfish range from 1/2” to 3/4” inches in length. Their bodies are flattened, long and slender, broad at the front and tapering gradually toward the rear. The antennae are long and slender. Three long, slender appendages are found at the rear of the body, giving them the common name, “bristletails.” All silverfish are wingless and their development takes place without metamorphosis.
Silverfish Life Stages
Silverfish mature through the developmental process known as ametabolous, (“no”) metamorphosis. Newly hatched silverfish young, or nymphs, look like tiny adults except that the characteristic body scales do not usually appear until at least the third molt. Unlike other insects, silverfish molt continuously throughout their life, passing through 45-60 instars or developmental stages.
Silverfish can lay eggs at any time throughout the year. Females lay their eggs in crevices, on cloth, or buried in food or dust. The average number of eggs laid varies from 50-200. Eggs take 19-43 days to hatch and sexual maturity in silverfish may be reached in two to three months or as long as two to three years from hatching. Silverfish are nocturnal and can be active year-round in dark areas throughout the structures they inhabit.
Silverfish are considered a household pest, due to their consumption and destruction of property. Although they are responsible for contamination of food and other types of damage, they do not transmit disease. Silverfish have very weak mandibles, or jaws, and do not bite humans. Silverfish are nuisance pests and feed on paper; particularly paper that has paste attached. They are especially fond of the sizing in paper and will attack wallpaper, books, and drywall.
Silverfish may be found almost anywhere in a home, preferring damp warm areas such as laundry rooms. However, they can also be found living close to their source of food. They eat a wide variety of foods containing protein and carbohydrates. Rolled oats, flour, starch, paper, cotton, sugar, dead insects, glue, paste and linen are all normal items in their diet. Silverfish can also attack tapestries and live for long periods without food.
Silverfish Extermination and Control in San Francisco
The key to silverfish control is to thoroughly inspect preferred habitat areas, such as basements, kitchens, attics and bathrooms. Follow these tips to keep silverfish from entering your home.
- Finding small irregular shaped holes in fabrics is a common sign of silverfish. Irregular shaped holes in wallpaper is another indicator as these insects are fond of glue.
- Small irregular holes and yellow stains on clothing or fabric are usually signs of silverfish damage.
- Outside, silverfish may be found in nests. These nests can belong to other insects, birds and mammals.
- Silverfish live under tree bark or mulch and are sometimes found in wood shingles or siding on homes.
Prevention and Control:
- Seal cracks and crevices around the home with caulking and make sure window and door screens are tight fitting.
- Seal dry goods like cereal, pasta, rice, quinoa, flour, sugar and pet food in sturdy airtight containers to prevent silverfish from reaching a food source.
- Remove any possible harborage areas such as leaf and grass litter around the home, and keep gutters cleaned out.
- Remove clutter. Silverfish feast on old papers, magazines and books. Dispose of items you no longer need and store paper items in airtight bins.
- Cinnamon is used as a home remedy to get rid of silverfish as it smells pleasant to humans but silverfish can’t stand it. Put cinnamon sticks in drawers, and in kitchen and bathroom cabinets.
- Place boric acid around the areas of your home where you suspect silverfish activity. Boric acid is a natural element that is generally safe for humans, but deadly to insects.
- Diatomaceous earth can be applied both indoors and outdoors and is safe if consumed by pets. Although it has no effect on humans or pets, this product works by scratching the exoskeleton of silverfish, which leads to dehydration and death.