Earwigs (Dermaptera) are common insects characterized by their elongated bodies and a prominent pair of pincer-like appendages, known as cerci, located at the rear of the abdomen. While they play a beneficial role in consuming aphids and decaying matter, they become a nuisance when their populations swell, leading to damage in gardens and occasionally migrating indoors. Earwigs feed on a variety of soft-bodied plants, young seedlings, flowers like dahlias and marigolds, and ripe fruits, leaving behind irregular holes and ragged edges on the foliage. Repelling earwigs effectively involves understanding their preference for dark, moist environments and using this knowledge to implement long-term control strategies.
Modifying the Environment for Long-Term Control
The most fundamental step in repelling earwigs involves eliminating the conditions that attract them, namely excessive moisture and readily available shelter. Earwigs thrive in damp environments and hide during the day in cool, dark spots near the ground. Removing debris piles, such as leaf litter, old wood, and excess mulch, from around the home’s foundation and garden beds significantly reduces their available habitat.
Proper moisture management is equally important, as earwigs migrate toward water sources. Fixing leaky outdoor faucets, irrigation systems, and ensuring that gutters and downspouts drain water away from the structure helps create a drier perimeter. Trimming back dense groundcover and vegetation that holds moisture close to the foundation also minimizes the damp, shaded areas that earwigs seek out. Addressing indoor moisture issues, such as using a dehumidifier in basements or crawl spaces, prevents earwigs from seeking refuge inside.
Utilizing Natural Scents and Substances
Certain natural substances and strong scents can actively deter earwigs and create barriers they prefer not to cross. Food-grade diatomaceous earth (DE) is a popular, non-toxic powder made from the fossilized remains of aquatic organisms. The fine, sharp particles of DE scratch the earwig’s outer layer, causing the insect to dehydrate and eventually die. This powder is most effective when applied thinly to dry areas around entry points and plant bases, though it must be reapplied after rain or watering.
Essential oils with pungent aromas also act as effective repellents by masking the chemical cues earwigs use for navigation. Peppermint, eucalyptus, cinnamon, and tea tree oils are frequently cited for their deterring properties. A simple spray solution can be created by mixing a few drops of these oils with water and applying it to affected areas or potential hiding spots. A simple mixture of water and liquid dish soap can also be sprayed directly onto earwigs as a contact killer, as the soap weakens their exoskeleton.
Strong-smelling herbs, such as basil and dill, may also contribute to a less inviting garden environment. A powerful, homemade repellent is a garlic oil spray, created by soaking crushed garlic in oil and then mixing the strained liquid with soapy water. This mixture can be safely applied to plants to discourage feeding.
Physical Barriers and Trapping Strategies
Physical barriers and trapping offer immediate, non-toxic methods for preventing earwig access and reducing localized populations. To protect vulnerable plants or fruit trees, a sticky barrier can be applied around the trunk or stem. Wrapping the trunk with a strip of plastic or duct tape coated with a sticky adhesive, such as petroleum jelly, prevents earwigs from climbing up to feed on fruit.
Simple shelter traps exploit the earwig’s nocturnal habit of seeking dark, tight spaces for daytime refuge. Rolled-up newspapers, corrugated cardboard, or short pieces of garden hose can be placed on the ground near damaged areas overnight. The insects will crawl inside, allowing the traps to be collected the next morning and disposed of in a bucket of soapy water.
Another effective removal method is the oil-pit trap, which uses a can sunk into the ground with the rim flush with the soil surface. Filling the can with vegetable oil and adding an attractant like bacon grease or fish oil will lure the earwigs, which then fall in and drown. Daily monitoring and emptying of these traps can significantly reduce earwig numbers in a localized area.