Earwigs are common nocturnal inhabitants of gardens and landscapes. Although they are omnivores that consume decaying matter and other small insects, they become pests when they seek out tender, living plant material. Identifying the specific damage they leave behind is the best way to confirm their presence, as they are rarely seen feeding during the day. The damage often appears overnight, characterized by small, irregular chew marks on various parts of the plant.
Key Signs of Damage to Foliage and Flowers
Earwigs use their chewing mouthparts to feed on various plant tissues, resulting in an appearance that is often described as ragged or tattered. This damage is frequently observed on younger, softer leaves, where the tissue is easier for the insect to consume. The result is often numerous small, irregular holes scattered across the leaf surface, sometimes resembling a “shot-hole” pattern.
Leaves on older, more established plants may show chewing concentrated around the edges, giving them a frayed look. If the infestation is severe, earwigs can reduce older foliage to little more than a network of veins. Seedlings and annual flowers are particularly vulnerable, as damage to the stem or primary leaves can be devastating to the entire young plant.
Damage to flowers is also noticeable, particularly on popular garden ornamentals like dahlias, roses, and marigolds. Earwigs chew holes into the petals, often leaving ragged or scraped-looking edges on the blooms. Because they prefer soft tissues, the delicate petals are highly susceptible to this nocturnal feeding.
Damage to Ripening Fruits and Vegetables
Earwig feeding targets edible crops that are nearing harvest. They frequently attack soft fruits such as strawberries, apricots, peaches, and raspberries. The damage appears as shallow cavities or gouges chewed into the surface of the fruit.
The shallow depth, ranging from about one-eighth to one-quarter of an inch deep, distinguishes this damage from the deeper, more defined tunnels of other pests. Earwigs are attracted to the sweetness and moisture of the maturing produce. They may enter damaged fruit or take advantage of natural openings, such as the split-pits sometimes found in peaches.
In vegetable gardens, earwigs are drawn to crops like lettuce, celery, and sweet corn. They may hide within the tight folds of lettuce heads, feeding internally and contaminating the crop. On corn, they target the silk strands, which can interfere with the pollination process and result in poorly developed kernels.
Non-Plant Damage and Distinguishing Characteristics
Indoor Nuisance
While earwigs primarily feed on organic matter and plants, they occasionally become nuisance pests inside structures, especially when seeking moisture. They do not typically cause structural damage, but they may chew on damp paper products, fabrics, or insulation. Their presence indoors is generally a sign they are seeking a dark, cool, moist environment, not necessarily a food source.
Distinguishing Damage
Identifying earwig damage requires distinguishing it from other common garden feeders, which is often done by looking for accessory signs. Earwig damage can sometimes resemble that caused by slugs or snails, but earwigs leave no shiny, telltale slime trails. Finding small, black, pellet-like droppings, known as frass, near the chewing site can help confirm earwig activity.
The feeding marks are also distinct from those of many caterpillars, which typically leave larger, cleaner-cut holes. Earwig damage tends to be more numerous and ragged, and unlike caterpillars, earwigs do not leave behind webbing or pupae. The most definitive characteristic is their nocturnal pattern; confirming the damage involves checking the plants with a flashlight after dark, or finding the earwigs hiding in dark, moist shelters near the damaged area during the day.