Earwigs are common in gardens, often becoming unwelcome guests when their populations surge and they feed on tender plant material. While they are omnivorous and can be beneficial by preying on aphids and scavenging decaying matter, a large presence can damage young seedlings, soft fruits like strawberries, and delicate flower petals. Gardeners seek practical solutions to reduce their numbers, especially since their nocturnal feeding results in ragged holes in leaves and flowers overnight. The following methods focus on environmental adjustments and targeted removal.
Identifying Earwig Activity and Preferred Habitats
Identifying the pest is the first step, as earwig damage can be mistaken for that caused by slugs or caterpillars. The earwig is easily recognized by its elongated, reddish-brown body, measuring about three-quarters of an inch long, and the prominent pair of forceps-like pincers extending from its abdomen. The damage appears as irregular, ragged holes in leaves or shallow gouges in fruits, but it lacks the glistening slime trail left by slugs and snails.
Earwigs are strictly nocturnal, emerging after dark to feed. During the day, they seek out dark, cool, and moist environments to hide. Preferred habitats include areas under dense mulch, potted plants, stones, boards, and piles of leaf litter or other garden debris. An abundance of these sheltered spots indicates an environment conducive to a large earwig population.
Removing Hiding Spots and Moisture Sources
Long-term control begins with modifying the garden environment to make it less hospitable to earwigs, which cannot survive in dry conditions. The primary focus should be eliminating the dark, moist refuges where they congregate during the day. This involves proactively clearing away any garden debris, such as old boards, loose stones, or piles of weeds and leaf litter, especially those close to vulnerable plants.
Managing your use of mulch is an important cultural practice for earwig management. While mulch is beneficial for soil health, wood chips and organic materials near the base of plants provide ideal shelter. Reducing the thickness of mulch around the stems of susceptible plants can discourage daytime hiding.
Controlling soil moisture is also a powerful deterrent, since earwigs are highly attracted to dampness. Adjusting irrigation schedules to water early in the morning allows the soil surface to dry out before nightfall, when the earwigs become active. Check for and repair any leaky faucets or hoses that create persistently damp areas near garden beds or the foundation of a home. Creating a dry border of gravel or stone directly adjacent to structures can also help prevent them from seeking shelter nearby.
Targeted Trapping and Elimination Methods
Reducing the population can be achieved through passive trapping and targeted, low-toxicity applications. Trapping methods capitalize on the earwig’s preference for darkness and certain odors.
Passive Trapping
A simple, passive trap involves rolling up a damp newspaper or corrugated cardboard and placing it near infested plants overnight. Earwigs will crawl inside to hide by morning. Collect the roll and shake the insects into a bucket of soapy water for disposal.
Active Lures
For an active lure, use a shallow container, such as a tuna can, as a pit trap. Fill the container with equal parts vegetable oil and soy sauce, and bury it so the rim is level with the ground. The salty scent attracts the earwigs, and the oil layer prevents them from escaping.
Contact Elimination
Targeted elimination utilizes mechanical and contact products; broadcast chemical spraying is generally unnecessary. Diatomaceous Earth (DE) is a fine powder that works by physically abrading the insect’s exoskeleton, leading to fatal dehydration. Apply a thin layer of food-grade DE around the base of plants where earwigs travel, reapplying after rain or heavy watering, as moisture renders it ineffective. Insecticidal soaps or pyrethrin-based sprays must contact the pest directly to be effective. Apply these products late in the day or at dusk to ensure contact with the nocturnal insects.