Earwigs are common garden insects, recognizable by the pincer-like appendages at the end of their abdomens. While they often feed on decaying organic matter, their populations can rapidly increase and shift their diet to include tender, living plant tissues. When this happens, earwigs become frustrating pests that require deliberate action to control.
Identifying Earwig Damage
Earwigs are nocturnal feeders, meaning you typically see the damage before you spot the pest itself. The most characteristic sign of their presence is irregular holes in leaves and petals, often giving the foliage a ragged, tattered appearance. This damage can easily be mistaken for that caused by slugs or snails, but earwigs do not leave a tell-tale slime trail behind them.
They also target soft fruits and vegetables, such as corn silk, strawberries, and apricots, often chewing shallow gouges into the surface. Finding small, black, pellet-like droppings, known as frass, near damaged plants confirms an earwig problem. An infestation is confirmed when monitoring plants at night with a flashlight and observing the pests actively feeding.
Immediate Removal Using Traps and Barriers
Physical traps offer a non-chemical way to immediately reduce earwig populations by capitalizing on their need for dark, moist shelter during the day. The simple oil-pit trap involves sinking a shallow container, such as a tuna can, into the soil so the rim is level with the ground. Filling this container with about a half-inch of vegetable oil and a drop of fish oil or soy sauce attracts the insects, which fall in and drown.
Another method uses the earwigs’ instinct to hide by creating harborage traps from rolled-up, moistened newspaper or pieces of corrugated cardboard. These are placed near affected plants in the evening and collected the following morning before the insects become active. The accumulated earwigs are then shaken out and disposed of in a bucket of soapy water.
For protecting vulnerable trees and plants, a physical barrier of petroleum jelly or a non-toxic sticky substance can be applied in a ring around the base of the stem or trunk. This barrier prevents the insects from reaching the upper, softer parts of the plant.
Targeted Treatments for Severe Infestations
When trapping alone does not resolve a severe earwig infestation, targeted applications of specific substances may be necessary. Diatomaceous Earth (DE) is a mechanical insecticide made from the fossilized remains of tiny aquatic organisms. When earwigs crawl over the fine, abrasive dust, the particles scratch their protective outer layer, causing them to lose moisture and dehydrate.
For this method to work, only food-grade DE should be used, applied as a fine layer around the base of plants only when the soil and foliage are completely dry. Moisture significantly reduces the effectiveness of the powder by neutralizing its sharp edges.
Low-toxicity insecticidal soaps or pyrethrin-based sprays can be used as a last resort, applied directly to the pests when they are active at night. When using these treatments, carefully read the label instructions and apply them sparingly to minimize the impact on beneficial insects and pollinators.
Changing the Garden Environment for Prevention
Long-term control relies on making the garden less appealing to earwigs, which thrive in damp, dark, and debris-filled environments. A primary step is to reduce moisture by watering plants in the early morning instead of the evening, allowing the soil surface to dry before the earwigs emerge to forage at dusk. Improving drainage in overly wet areas will also deter them from establishing colonies.
Removing potential daytime hiding spots is an effective preventative measure. This involves clearing away piles of leaf litter, loose boards, stones, or unnecessary debris from the garden beds and near the foundation of any structures. If mulch is used, keep it pulled back several inches from plant stems and the base of structures. Alternatively, consider replacing thick organic mulches with a dry, inorganic material like gravel in problem areas.