What is the Lifecycle of the Earwig?

There are over twenty species of earwigs in North America so there are slight variations in the life cycle of each but there are many similarities. As part of the lifecycle of earwigs, they undergo simple metamorphosis. Metamorphosis is the process of changing stages from egg to adult in insects. In simple metamorphosis, the stages are rather basic: egg, nymphs (stages of juveniles), and adult. Nymphs typically resemble the adults but on a smaller scale. Simple metamorphosis is also called gradual metamorphosis. Other insects go through complete metamorphosis and the stages here are egg, larva, pupa, and adult. The larva resembles are worm and later, the larva will rest in a pupal stage prior to emerging as an adult.  Complete metamorphosis is typical of moths and butterflies.

Usually, only adult earwigs overwinter, or survive the change of seasons into cooler weather. This is probably because the adults are more suited to changing climate and environments. Also, feeding opportunities are less available during the winter making adults more durable. Typically, the young are full adults by the onset of winter.

Since earwigs undergo simple metamorphosis, the eggs hatch and the first instar is the first stage to appear. While it doesn’t look exactly like adults, the similarities are striking.  As the earwig grows, it sheds its shell as the shell is not flexible enough to grow by itself. As the shell is shed, the next instar is soft bodied and usually appears whitish until the shell starts to harden into a darker, more durable, and harder shell. The process of hardening and ultimately, darkening in most cases is called sclerotization and as the skin or shell is hardened it is called sclerotized.

Since earwigs go through several instars, the first instar, second instar, etc., as they move from egg to adults, with adequate food they can reproduce during warm weather and emerge as full adults prior to the end of the season.