The Pamphlet Collection of Sir Robert Stout: Volume 14
Strictly and scientifically speaking the thousand legs are not insects, though they are generally considered and may be treated page 26 here as such. They undergo no transformation like wireworms and other insects proper, and have only two stages of life, viz., the egg stage, and the caterpillar, or worm stage.
From the end of December to the beginning of May the female lays eggs in considerable numbers under stones, in decaying wood, and vegetation, in the roots of the hop plants, and in other retreats where there is dampness. When the young emerge from the eggs they have at first only three pairs of legs, according to Taschenberg, but the number of legs increases. They are not full grown, Curtis says, until they are two years old, changing their skins, or moulting, five times during this period and feeding actively throughout. It is believed that like wireworms they live four or five years from the time they come from the eggs.