Silverfish
Most common household species
Silverfish (Lepisma saccharina)
Size
Up to 11 mm
Lifespan
Up to four years
Reproduction
Up to 70 eggs, development takes several months
Food
Materials rich in starch and sugar
Damage
Feeding damage to food, wallpaper, books, pictures, starched clothing
Control measures
Drying (lowering of the humidity level or use of diatomaceous earth), insecticidal bait
Detailed description
Silverfish belong to the Apterygota and have no wings during any stage of development. They get their name from their teardrop-shaped bodies and from the silver scales that the older insects usually have.
The most common species of silverfish is Lepisma saccharina. The information provided below pertains only to this species. This species of silverfish measures up to 11 mm long and has three bristle tails measuring approx. 3 mm. The silvery scales are mechanoreceptive sense organs.
Silverfish need a warm and humid environment, and are therefore primarily seen in bathrooms. The eggs of silverfish, of which 70 are usually laid, are oval, whitish and about 1 mm long. Older eggs turn a brownish colour. Larvae hatch after 25 days at 30°C; at 20°C they take 40 days to develop. Larvae are a whitish colour at first. The silver scales appear after the second moulting stage. They moult another four to five times until they reach adult form. Adults also shed on a regular basis. Silverfish can live up to the age of four
Silverfish avoid daylight and hide in crevices and other suitable places during the day. These thin-skinned insects require a high level of high humidity, ideally over 70% humidity. Silverfish can move fast, but they are not capable of climbing up perfectly smooth walls. They eat materials which are rich in starch and sugar. They have hunger periods lasting up to ten months. Silverfish are inactive during cold periods.
Since starch and sugar are contained in a wide range of materials, they can cause damage to food, such as pasta, pastries or legumes. Wallpaper, books, pictures, museum objects and starched clothing can also be damaged.
Since silverfish require a highly humid environment, lowering the humidity to below 30% humidity is deadly for them. The animals also die at temperatures above 35°C.
Silverfish can be combated with bait containing an insecticide.
