The earwig, an insect belonging to the order Dermaptera, is a common, slender creature found in nearly every terrestrial habitat worldwide, excluding the polar regions. This nocturnal insect is often misunderstood due to its common name, which originated from a centuries-old superstition that the insect would crawl into the ears of sleeping people. This misconception has persisted through folklore, despite having no basis in fact. There are approximately 2,000 species of earwigs, characterized by their unique body structure.
Identifying Features and Common Myths
The most recognizable feature of the earwig is the pair of forceps-like appendages, known as cerci, located at the rear of its abdomen. These cerci serve multiple functions, including defense, capturing prey, and assisting in mating rituals. A difference exists between the sexes: the male’s cerci are typically more robust and curved, while the female’s cerci are generally straighter and more slender.
The alarming appearance of the cerci, combined with the insect’s name, contributes to the enduring myth that earwigs intentionally burrow into human ears or brains. This is purely folklore, as earwigs are outdoor dwellers that prefer dark, moist environments like leaf litter and soil crevices. While accidental entry into an ear canal is possible, they pose no threat. The cerci are incapable of piercing human skin or an eardrum, instead being used to hold food or for defense against other small organisms.
The Earwig’s Role in the Ecosystem
The earwig functions as a highly adaptable omnivore, occupying a dual role as both a scavenger and an opportunistic predator within its ecosystem. The insect contributes to the environment in two primary ways. First, earwigs act as effective decomposers, helping to recycle organic matter by feeding on decaying plant material, fungi, and sometimes animal carrion.
This scavenging behavior is important for soil health, as it breaks down detritus and returns nutrients to the substrate, enriching the environment for plant life. Second, earwigs serve as natural biological controls by preying on numerous garden and crop pests. Their nocturnal foraging habits allow them to hunt soft-bodied arthropods that are active at night.
Specific prey includes insect eggs, mites, and especially aphids, which they consume in substantial numbers. In commercial settings like apple orchards, the European earwig species, Forficula auricularia, has been shown to be an effective predator of the woolly apple aphid. This predation helps regulate pest populations, reducing the need for chemical interventions.
Specialized Parental Care
A characteristic that sets earwigs apart from most other insect species is the specialized maternal care exhibited by the female. After mating, the female digs a small nest burrow in the soil beneath debris, where she will lay a clutch of 20 to 80 eggs. This period is marked by intense parental investment, as the mother actively guards the eggs from predators and potential pathogens.
The female constantly cleans the egg clutch using her mouthparts, a behavior that prevents the growth of mold and fungi that would otherwise destroy the developing embryos. If the mother is removed from the clutch, the survival rate of the eggs drops significantly, underscoring the importance of this cleaning activity. Following the eggs’ hatching into small nymphs, the mother often remains with her offspring for a period.
She continues to protect the young nymphs and may even provide food for them, sometimes through regurgitation, until they have undergone their first or second molt. This sustained post-hatching care is a complex behavior rarely observed outside of social insects.
Managing Earwigs in Human Environments
Earwigs primarily become a nuisance when they seek shelter or moisture in human dwellings or when they feed on cultivated crops. They often enter homes during periods of hot, dry weather while searching for damp environments, or they may be accidentally carried indoors in firewood or produce. Damage to plants usually occurs in gardens where they feed on tender seedlings, flowers, or soft fruits like strawberries and apricots.
Management strategies that minimize conflict with earwigs focus on habitat modification. Reducing the number of dark, moist hiding spots around a structure is effective, which involves clearing piles of leaf litter, wood, and organic mulch from the foundation of the home. Ensuring proper drainage and fixing leaky outdoor faucets or irrigation systems removes the moisture sources that attract them.
Simple, non-toxic traps can also be used to monitor and reduce local populations outdoors, such as rolled-up damp newspaper or corrugated cardboard placed in garden areas overnight. By focusing on environmental alterations rather than chemical control, co-existence can be maintained, allowing the earwig to continue its beneficial roles as a scavenger and predator in the outdoor ecosystem.