Silverfish

SIZE:

Adults are up to 3/4 inch long

COLOR:

Silvery to Brown

DESCRIPTION:

Silverfish are always wingless and their bodies are covered with fine scales. They are generally soft bodied. Adults are up to 3/4 inch long, flattened from top to bottom, elongated and oval in shape, have three long tail projections and two long antennae.

HABITAT:

Silverfish are chewing insects and general feeders but prefer carbohydrates and protein, including flour, dried meat, rolled oats, paper and even glue. They can survive long periods, sometimes over a year, without food but are sensitive to moisture and require a high humidity (75% to 90%) to survive. They also have a temperature preference between 70 and 80 degrees F. They are fast running and mostly active at night and generally prefer lower levels in homes, but may be found in attics.

LIFE CYCLE:

Females lay eggs continuously after reaching the adult stage and may lay over 100 eggs during her life. Eggs are deposited singly or in small groups in cracks and crevices and hatch in 3 to 4 weeks. Silverfish develop from egg to young to adult within 4 to 6 weeks and continue to molt throughout their life. Immature stages appear similar to adults except they are about 1/20 of an inch long when they first hatch and whitish in color, taking on the adults’ silver coloring as they grow. They are long-lived, surviving from two to eight years. Simple metamorphosis (egg, nymph, adult).

TYPE OF DAMAGE:

Primarily a nuisance pest inside the home or buildings; they can contaminate food, damage paper goods and stain clothing; medically harmless. Many of their habits are similar to cockroaches and they appear to be more common as household pests in drier areas. Occasionally damage book bindings, curtains, wallpaper. Damage is only significant if a large population is present for a long period of time.

CONTROL:

Sanitation should be used to avoid infestations of silverfish. Although it should not be the only means to eliminate infestations. Remove old books, magazines and newspapers. Inspect fabrics that have been stored for long periods for damage or infestation. If books or fabrics will be in storage, store these items in sealed plastic containers. Many times valuable books or papers have infestations of silverfish. These items can be placed into a sealable plastic bag and placed into the freezer for several days to kill the silverfish. Clean closets on a regular basis to help remove harborage areas. Vacuum regularly and clean up spilled food or drink immediately. Make sure to inspect any items brought into the home, especially those that have been in storage, to avoid an infestation. In areas of infestation, or areas where books are stored, reduce humidity by using air conditioning units, fans or dehumidifiers. Repairing any plumbing leaks will cut off water sources for these insects. Insecticide treatments should be targeted to harborage areas such as cracks and crevices, around baseboards, closets and attics. With large infestations, small holes may be drilled in walls to treat the wall void. Look for products labeled to control silverfish, firebrats or bristletails. Natural active ingredients include d-limonene, clove oil, thyme oil, boric acid or diatomaceous earth. Synthetic active ingredients are items such as bifenthrin, lambda-cyhalothrin, cypermethrin, permethrin or deltamethrin. Formulations of the above mentioned products may be baits, dusts, or aerosols. These formulations should be used in crack and crevice treatments, in attics, wall voids and other areas inaccessible to children and pets. Dusts should be used with care, and should not be inhaled as they are being applied. It is advisable to use the services of a pest control operator when the infestations are large, persistent or hard to find. A commercial operator has the knowledge, training and equipment to perform safe and effective control.