Earwigs are a common sight in many gardens and around homes. These insects belong to the scientific order Dermaptera, encompassing approximately 2,000 known species globally.
Identifying Earwigs
Earwigs possess elongated, flattened bodies that typically measure between 7 and 50 millimeters (0.25 to 2 inches). Their coloration can vary, ranging from pale brown, yellow, and orange-brown to reddish-brown or dark brown and black. A prominent feature is the pair of forcep-like appendages, known as cerci, located at the rear of their abdomen. These pincers often differ between sexes, with males typically having more curved pincers than females.
Most earwig species possess two pairs of wings, with hardened, short forewings covering large, membranous hindwings that unfold like a fan. Despite having wings, not all earwigs fly, and those that do usually engage in short, infrequent bursts of flight. They have six legs and thread-like, segmented antennae that extend about half their body length.
Earwig Habits and Biology
Earwigs prefer environments that are damp, dark, and moist, commonly found under rocks, logs, leaf litter, and within soil crevices. Indoors, they may seek refuge in moisture-rich areas such as near sinks or in bathrooms. These insects are primarily nocturnal.
Their diet is omnivorous. Earwigs feed on decaying organic material, various plants including leaves, flowers, and fruits, and small insects such as aphids, mites, and insect larvae. Some species also act as predators, actively hunting other small arthropods.
Earwigs undergo incomplete metamorphosis, progressing through egg, nymph, and adult stages. Female earwigs exhibit a notable level of maternal care, laying eggs in burrows and diligently guarding and cleaning them. They continue to care for their nymphs, which resemble smaller versions of the adults, until the young are capable of independent survival, typically after their second molt.
Are Earwigs Harmful?
A common misconception about earwigs is the belief that they intentionally crawl into human ears to lay eggs or burrow into the brain. This notion is folklore. Despite their intimidating appearance, particularly their pincers, earwigs are generally not harmful to humans. These pincers are primarily used for defense against other insects, for catching prey, and during mating rituals.
While an earwig might pinch if it feels threatened or is handled, the pinch typically causes only minor discomfort and rarely breaks human skin. Earwigs are not venomous or poisonous, nor are they known to transmit diseases to humans. In gardens, they can be considered minor pests, potentially causing irregular holes in leaves and flowers. However, they also serve a beneficial role by preying on other common garden pests, such as aphids and mites.
Managing Earwig Presence
To reduce the presence of earwigs around and inside a home, managing moisture is a key step. This involves fixing leaky faucets, ensuring proper drainage around the foundation, and using dehumidifiers in damp areas like basements or crawl spaces. Sealing potential entry points into the home can also prevent earwigs from seeking shelter indoors. This includes caulking cracks and crevices in foundations and ensuring windows and doors have tight seals.
Removing organic debris from around the house, such as leaf piles, excess mulch, and wood piles, helps eliminate their preferred hiding and breeding grounds. A common trap involves burying a container with a mixture of oil and soy sauce, with the rim at ground level; earwigs are attracted to the bait and fall in. Focusing on environmental modifications and non-chemical approaches is generally recommended for managing earwig populations.