Common Household Pests: Silverfish

Introduction

Silverfish may cause damage in the home by eating foods or other materials that are high in protein, sugar or starch. They eat cereals, moist wheat flour, paper on which there is glue or paste, sizing in paper and bookbindings, starch in clothing and rayon fabrics.

Silverfish are common in homes. The silverfish lives and develops in damp, cool places. Large numbers may be found in new buildings in which the newly plastered walls are still damp. The firebrat lives and develops in hot, dark places, such as around furnaces and fireplaces, and in insulations around hot water or steam pipes.

In apartment buildings silverfish follow pipelines to rooms in search of food. These insects may be found in bookcases, around closet shelves, behind baseboards, windows or door frames.

They are are slender, wingless and are covered with scales. Adults are about 1/3 to 1/2 inch long. Silverfish are shiny and silver or pearl-gray in color. The young insects look like adults except they are smaller. They have two long slender antennae attached to their heads and three long tail-like appendages at the hind end. Each appendage is almost as long as the body. Silverfish are active at night and hide during the day. When objects under which they hide are moved, they dart about seeking a new hiding place.

Biology

Under usual house conditions, silverfish develop slowly and have few young. They are hardy and can live for several months without food.

Females lay eggs year around in secluded places, such as behind books or on closet shelves. Eggs are occasionally laid in the open. Silverfish lay only a few eggs at a time but may lay several batches over a period of weeks. The eggs are whitish, oval, and about 1/32 inch long. They hatch in two to eight weeks, depending on temperature.

Control

Residual sprays by a pest control technician are effective for controlling these insects. Control may not be immediate because hiding insects must come out and contact spray residue. Ten days to two weeks may be required to determine whether or not control has been achieved. Dusts are the recommended materials to be used for treating walls, voids, crawl spaces, and attics.