Thysanura (silverfish and 3 pronged bristletails)

Thysanura overview

Thysanura range in size from 0.5 to 2.0 cm. They have carrot-shaped bodies with 3 long segmented tail filaments. The filaments are bristled. They also have 2 cerci (singular: cercus) which can be mistaken for legs, see the image below. They run very fast and are difficult to catch. They undergo many moults - even as adults which is very unusual for an insect. They may live for as long as five years, and take around a year to reach maturity.

Silverfish overview

Silverfish require high humidity and usually live in buildings in colder climates. They feed on foods high in carbohydrates, and some may even be cannibalistic on occasion. There are around 370 species worldwide.

Silverfish lifecycle

The females can lay eggs throughout the year. A female can lay around 100 oval eggs in batches of as few as 2 - 3 in crevices and under objects.

The eggs are smooth and white when first laid, but turn wrinkled and brown after a while. The eggs hatch in around 2 weeks and reach maturity in just 3 months, but will not hatch unless humidity is at least 50%.

For the first few months, or until the third moult the silvery scales are absent.

Silverfish are able to regrow legs etc. which have been lost as they moult throughout their lives. They can live for over 3 years.

Silverfish mating

The males must perform a dance for the female, then he deposits a spermatophore on the ground. Then he attaches signal threads leading from it to guide the female to its whereabouts.

Although some species are parthenogenic.