The Silverfish

Silverfish

Silverfish

Silverfish

Silverfish

Latin: Lepisma saccharina

Silverfish are silvery glistening and can be up to 1 cm long. Silverfish hide in cracks and crevices during daylight. They are common in basements and attics, where they can be found in birds’ nests and old, abandoned wasps’ nests. Silverfish is practically omnivorous, with a preference for starchy foods. Their protein demands are covered largely by eating dead insects. They are somewhat able to digest cellulose, but they also graze on the mould that grows on damp paper. Each female lays up to 100 eggs, which are located individually in cracks and crevices. At 22 ° C the eggs hatch in just over 40 days. The tiny silverfish offspring is similar to the adults, except in size. At 27 ° C, silverfish grow up and mature in 3-4 months. Silverfish thrive at temperatures between 25 and 30 ° C. At temperatures below 15 ° C development stops. Silverfish can get quite old, up to 4 – 5 years.

Silverfish do not survive if the relative humidity, where they live, drops to below 75% RH. Silverfish are not a serious food pest, but since silverfish also seek food elsewhere, there is a risk for transfer of bacteria and other germs. A drying-out of the premises will usually clear the problem. In places where silverfish are not tolerated, dusting or spraying with insecticides is as a reasonable measure. Here you have to concentrate on the animals’ habitats and sweep lists, loose tiles, pipe penetrations, etc.

Silverfish

Season for silverfish

Season for silverfish

( Latin: Order Thysanura)

With their silvery scales and nimble, meandering movements, they can seem similar to glistening small fish. Silverfish have biting mouth parts and are insects. Characteristic are the three wires at the rear end. It’s been 300 million years since the first silver fish-like animal appeared. Some believe that all the various insect types we know today have evolved from silverfish-like insects. In hot climates the silver fish lives in nature, but in this country it is more common indoors than outdoors.

Silverfish

Silverfish

Silverfish

( Latin: Lepisma saccharina)

It is probably about 300 million years ago that the first animal looking somewhat like a silverfish saw the light of day. It was doubtless very widely distributed and occurred in enormous numbers, and it has been suggested that primitive animals of this type may well have been the ancestors of all the different insect types alive today. Some insects, including silverfish, have remained more or less unchanged over long periods. Indeed, it is likely that there were primitive insects of this type when the first fish went up on to land, that they crawled around the feet of the dinosaurs, and they are still with us. Silverfish can, in fact, be regarded as living fossils, com- parable with the coelacanth.

In spite of their antiquity, silverfish have succeeded in exploiting the new opportunities created by man. In southern Europe and in parts of Asia they live out in the open, under stones and in crevices, but elsewhere they are almost exclusively associated with human habitations – houses, stables, outhouses and so on. Most people must have seen these small silvery insects run to shelter in the evening when the light is turned on in the kitchen, or may have found them in a bath or wash basin. They do not, as many believe, come up the drainpipe, but they become trapped after sliding down the smooth walls of the bath while searching for food during the night. They are particularly prevalent in kitchens and bathrooms for they require a high humidity or access to water.

Silverfish are pleasant animals which are easy to keep in captivity and they live for quite a long time, sometimes over 5 years. On the other hand, they are not very prolific, because a female will only lay about twenty eggs during the course of her life. The eggs are deposited in cracks and crevices and the young resemble the adults, except in size. Under favourable conditions they become sexually mature at an age of about six months.

Silverfish will thrive on the tiniest scraps of food, preferring starchy foods such as flour and bread (p. 59), but they also gnaw meat and are not above eating dead members of their own species. They are capable of digesting cellulose and may therefore attack books and documents. In such cases damage is not usually very serious unless the goods have been kept in a damp condition.

Silverfish

These are omnivorous insects which occasionally gnaw textiles. They will, for example, attack artificial, cellulose-based silk, such as the red ribbon used in Christmas decorations and in gift wrappings.

Silverfish
Silverfish

Other insects which occasionally attack textiles include cockroaches and meal- worms, which sometimes feed on soiled linen.

On account of their size, mice and rats often cause serious damage to textiles when they are collecting nest material. In empty holiday houses which mice may enter during the winter it is a good idea to move mattresses and bedding to a place where the mice cannot get at them. For precautions against mice, see also p. 87.

Silverfish

(Latin: Lepisma saccharina)

The common silverfish frequently occurs in kitchens and comes out at night to feed on crumbs and odd scraps of food. It is capable of digesting cellulose and so can derive nutriment from paper. It is described in greater detail on p. 106 together with other pests that attack paper.