SILVERFISH / BRISTLETAILS
Don't see what you're looking for? Click here for more examples.
Need to control Silverfish? Click here.
SILVERFISH / BRISTLETAILS
COMMON NAME: Silverfish, bristletail
SCIENTIFIC NAME: Various
CLASS / ORDER / FAMILY: Insecta / thysanura / various
METAMORPHOSIS: No metamorphosis
INTRODUCTION. All members of the order Thysanura are ancient and not very different from when they were introduced on earth. have a teardrop / carro / 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. They cause a great deal of damage to many types of clothing and paper products. Silverfish is the common name for species within this group whose bodies are covered with silvery scales. Silverfish are a very common insect and are found throughout the United States and the world. Almost everyone has seen one at one time or another in his or her lifetime.
RECOGNITION. Adult body length, not including tails, is about 1/2-3/4”. They are wingless and have a flattened body. They have an unusual body shape, which is teardrop / carrot / fishlike and tapers from head to rear. They are generally covered with scales. Their color is from silvery to gun metal with one species having dark lines running the length of its body. The antennae are long and threadlike and look as though they repel each other from the dorsal view. Its posterior end of the abdomen has 3 long, bristle like appendages. In addition, the compound eyes are small and widely separated. Having no ocelli present, the coxae lack styli (fingerlike projections) with the tarsi being 3 or 4-segmented. Some abdominal segments have a pair of styli; abdominal sternites (underside of the body segment). There are no median setal combs (tufts of hair) or if present, the last abdominal tergite (upper side of segment) is longer than wide.
The immature caste is similar to adults in appearance, with the exception of size. Body scales begin to appear with 3rd or 4th body molt.
DAMAGE AND SIGNS OF INFESTATION. Feeding marks are irregular whether they are holes, notches along an edge, or surface etchings. Yellow stains, scales, and/or feces may be seen on infested materials.
BIOLOGY. The silverfish (L. saccharina) female lays up to 3 eggs per day, and places them in cracks, under objects, or occasionally leaves them exposed. Egg hatch requires relatively high temperatures of from 72-90°F and at least 60-75% relative humidity. Developmental time (egg to adult) is approximately 3-4 months under favorable conditions, but occasionally may require up to 2-3 years. The large majority live about 3 years and the most favorable conditions are from 72-80ºF and up to 97% RH. Attics are favorite breeding places for silverfish.
The four lined silverfish (C. lineata) and gray silverfish (C. longicaudata) produces the enzyme cellulase in its midgut and have the ability to digest cellulose. These are the easiest silverfish to spot from their damage found on paper insulation covers or other paper found in the attic.
HABITS. All these silverfish species hide during the day and prefer to hide or rest in tight cracks or crevices. They can be found almost anywhere in a house including living rooms, bedrooms, bathrooms, attics, basements, and garages. Silverfish infest commercial structures such as offices, stores, and libraries. They tend to roam quite some distance while searching for food, but once they find a satisfactory food source, they remain close to it. Within structures, they can be breeding in a variety of areas, including wall voids, in/under the sub-flooring, attics, etc. Silverfish can survive for weeks without food or water.
Silverfish (L. saccharina) prefer areas of room temperature (70-850F) and high relative humidity (75-100%).
They prefer proteins to carbohydrates and are cannibalistic. Silverfish are often introduced into buildings via cardboard cartons of books and papers from an infested location. They are pests of paper, particularly of glazed paper and paper with sizing, wallpaper and wallpaper paste, etc. Silverfish eat proteins such as dried beef and dead or injured of their kind.
The four lined silverfish is not so limited by temperature and moisture. They may be found throughout a building, in the basement, in wall voids, the attic especially if the roof has wooden shingles, and in the garage. Outdoors, it occurs in the mulch of foundation flower and shrubbery beds, and under the bark of Eucalyptus trees in California.
The gray silverfish can be found throughout a building from basement to attic, but are not found outdoors. Often heat ducts and ventilators from the basement serve as avenues for widespread infestation. They survive well in both dry and moist conditions. Gray silverfish feed on carbohydrates and proteins of both plant and animal origin. They are fond of wheat flour and beef extract, especially when used as a paste on paper. Gray silverfish prefer papers of high chemical pulp content such as onion skin, cleansing tissue, cellophane (almost pure cellulose), etc., as opposed to newsprint, cardboard, and brown wrapping paper. They readily eat artificial silk, linen, rayon, lisle (long-strand cotton), and cotton, but not wools or true/natural silks; linen is most preferred.
