Earwig

Earwigs are insect arthropods of the order Dermaptera. The earwig gets its name from the old English word *earwicga*. This means ‘ear creature’ or ‘ear beetle’. The belief used to be, that an earwig would crawl into people ears, burrow into their brain and lay eggs, eventually killing the person. Of course this is not true at all, but some people are still scared of earwigs for that reason. In truth, earwigs are virtually harmless to humans and would much rather lay eggs under rocks than in your ears.

Anatomy
Earwigs are insects that have a flattened, cylindrical body with an elongated abdomen with large forceps called cerci at the end. The cerci are mostly used for defense. The common European earwig (Forficula auricularia) ranges in size from about 8mm-18mm or about ¾ of an inch, but there are some varieties like the St. Helena Giant Earwig (Labidura herculeana) that can grow to more than 8cm long. Some earwigs have wings, whereas others don’t. For species with wings, there are two sets, one to fly with and the other to protect the flying wings. The protecting wings are called tengmina and are short, leathery, and without veins in them. The flying wings are thin and membrane-like, and can be folded and unfolded very quickly.

Males and females can be distinguished by the abdomen section. A male’s cerci (pincers) are curved where as the female’s are more straightened. Also a male’s abdomen has ten visible segments and a female’s abdomen only has eight.

Reproduction
A female earwig, during early spring, will indiscriminately mate with males. The Cerci can be used to hold on to one another while mating. After mating, the female will find a dark, protected place such as under rocks or in cracks. She will lay 20-50 eggs which are smooth and cream colored. While in the nest the mother will clean her eggs with her mouthparts to prevent fungal infections and will guard them from predators.

After the eggs hatch, a mother will protect her young until they can start to forage for food on their own. Some females have been observed to even eat their own children after protecting them until this point.

Ecology
Earwigs have been found to inhabit almost all tropical and temperate climates. The common earwig is native to Europe and has been introduced to ecosystems all over the world. Earwigs are nocturnal animals, meaning that they will rest during the day and are active at night. They like to sleep in large groups in undisturbed, dark places such as, under rocks, in wood piles, and under various other debris.

Earwigs feed during the night and are omnivores. They will eat dead plant material and dead or slow invertebrates. They also might use their cerci to catch prey, but that has not been proven.

Birds and mammals are some of the common predators for earwigs. When threatened an earwig can secrete a bad-smelling noxious fluid to scare off predators. Also they can use their cerci to pinch any potential attackers.

Metamorphosis
Metamorphosis is the process by which an organism grows from being an egg to becoming an adult. An earwig undergoes an incomplete metamorphosis during its life cycle. This means that there are only three stages of an earwig’s life. The first stage is an egg. The second is a larval stage in which the earwig is called a nymph. The nymph looks very much like the adult but it has only the buds of wings, the reproductive organs aren’t developed and the cerci are very short and undeveloped.

A nymph will molt (shed its skin to make room to grow) about four or five times before fully becoming an adult. Normally, it takes about ten weeks for an earwig to go through the nymph stage. An adult earwig will typically live from eight to ten months.