Silverfish are nocturnal insects typically 13–30 mm long. Their abdomens taper at the end, giving them a fish-like appearance. The newly hatched are whitish but develop a greyish hue and metallic shine as they get older. They have three long cerci at the tips of their abdomens, one off the end of their body, one facing left and one facing right. Silverfish typically live for two to eight years.
Distribution
Silverfish are a cosmopolitan species, found in Africa, the Americas, Asia, Australia, Europe, and other parts of the Pacific. They inhabit moist areas, requiring a relative humidity between 75% and 95%.
Ecology
Silverfish consume matter that contains polysaccharides, such as starches and dextrin in adhesives. These include book bindings, carpet, clothing, coffee, dandruff, glue, hair, some paints, paper, photos, plaster and sugar. Silverfish are considered household pests, due to their consumption and destruction of property and infestations can be typically found in kitchens, laundry rooms, bathrooms, attics and basements. Silverfish can survive in almost any environment but they prefer areas with high humidity. As a rule of thumb, sort out the moisture and humidity, and you will address the silverfish issue.
The reproduction of silverfish is preceded by a ritual involving three phases, which may last over half an hour. In the first phase, the male and female stand face to face, their trembling antennae touching then repeatedly back off and return to this position. In the second phase the male runs away and the female chases him. In the third phase the male and female stand side by side and head-to-tail, with the male vibrating his tail against the female. It’s quite a tricky little routine!
The male lays aspermatophore, a sperm capsule covered in gossamer, which the female takes into her body via her ovipositor to fertilise the eggs. The female then lays groups of 50 odd eggs at once, deposited in small crevices. The eggs are oval-shaped, whitish, about 0.8 millimetres long, and take between two weeks and two months to hatch. A silverfish usually lays fewer than 100 eggs in her lifetime.
When the nymphs hatch, they are whitish in colour and look like smaller adults. As they moult, young silverfish develop a greyish appearance and a metallic shine, eventually becoming adults after three months to three years. They may go through 15 to 70 moults in their lifetime, sometimes 30 in a single year, which is much more than usual for an insect. Silverfish are among the few types of insect that continue to moult after reaching adulthood.
Ecology
Lepisma saccharina, commonly known as a Silverfish or Fishmoth, is a small, wingless insect in the order Thysanura. Its common name derives from the animal’s silvery light grey and blue colour, combined with the fish-like appearance of its movements.
