Earwigs are nocturnal insects that transition from beneficial scavengers to garden pests when their populations rise. While they primarily feed on decaying organic matter and smaller insects like aphids, they readily target tender new growth. Damage becomes noticeable when these pests chew irregular holes in leaves, damage flowers, or feed on soft fruits. This feeding behavior often escalates during dry periods, driving them to seek sustenance in irrigated garden beds when their usual food and moisture sources diminish.
Modifying the Garden Environment
The most effective long-term strategy for managing earwigs involves making the garden environment less hospitable. Earwigs prefer dark, cool, and damp conditions, spending their days hidden away from light and heat. Eliminating these harborages reduces their daytime survival rate. Start by implementing cultural controls that limit surface moisture, such as switching to drip irrigation or watering plants only in the early morning. This allows the soil surface and plant foliage to dry out completely before the earwigs become active at night.
Removing potential daytime shelters from the vicinity of vulnerable plants is important. Clear away accumulated debris, such as piles of cut grass, loose boards, and excessive leaf litter. Thin or remove dense, low-growing ground covers near vegetable patches to reduce humid cover. Even thick mulch provides an inviting hiding place, so consider pulling it back slightly from the base of susceptible seedlings.
Creating a dry perimeter around garden beds can further deter earwig migration. This buffer zone can involve substituting organic mulch with a gravel or stone border next to foundations or vulnerable plantings. Disrupting the continuous moist habitat makes the garden a less appealing destination for these moisture-dependent insects. Regularly turning over the top layer of soil in less-used areas can also expose hidden earwig eggs or juveniles to natural predators.
Setting Physical Traps and Lures
Active trapping reduces existing earwig populations without chemical treatments. These physical traps exploit the insect’s need for a dark, sheltered spot to rest during the day. A straightforward shelter trap can be created by loosely rolling up a newspaper or corrugated cardboard and placing it on the soil near affected plants in the evening. Earwigs crawl inside seeking refuge overnight, allowing for easy collection the following morning.
Another effective method is the use of a baited oil trap, which attracts and traps earwigs in liquid. To construct one, use a small, low-sided container, such as a tuna can, and bury it so the rim is flush with the ground surface. Fill the container halfway with vegetable oil and add a few drops of an attractant like bacon grease or soy sauce. The pests are lured by the scent, fall into the oil, and are unable to escape due to the slick surface tension.
Both types of traps must be checked and emptied daily for successful population reduction. For shelter traps, shake the contents into a bucket of soapy water to eliminate the captured insects. Oil traps require disposing of the trapped earwigs and replenishing the oil mixture every few days or when full. Consistent daily trapping for several weeks can significantly lower the overall earwig count, protecting susceptible plants from damage.
Applying Targeted Pest Control Treatments
When cultural controls and trapping methods are insufficient, targeted material applications offer another layer of defense. Food-grade Diatomaceous Earth (DE) is a mechanical insecticide composed of fossilized diatoms. When earwigs crawl over the fine powder, it abrades their waxy exoskeleton, leading to lethal dehydration. Dust this material lightly around the base of plants or at the edges of garden beds. It must be reapplied after rain or heavy watering, as moisture renders it ineffective.
Commercially available earwig baits contain an attractant mixed with a slow-acting insecticide. Sprinkle these baits thinly around areas where earwigs congregate. For safety, place baits strategically away from edible plants, such as along foundation walls or under dense shrubbery. Always choose a product specifically labeled for earwigs and follow instructions precisely to protect pets and beneficial insects.
For immediate knockdown, insecticidal soaps or natural pyrethrin sprays can be used. Because earwigs are nocturnal, these contact sprays are most effective when applied late in the evening when pests are actively feeding. Confirm that any spray product is safe for use on edible plants. Avoid spraying flowering plants to protect pollinators, as these broad-spectrum treatments affect any insect they contact.