The earwig is a common garden insect recognized by the prominent pair of pincer-like appendages, called cerci, extending from its abdomen. These nocturnal creatures hide in dark, damp places during the day. Yes, earwigs consume plants, but this is only one part of their broader diet. Understanding their feeding habits clarifies their role in the garden ecosystem.
The Earwig Diet: Omnivore or Carnivore?
Earwigs are classified as omnivores, meaning their diet includes both plant and animal matter; they are highly opportunistic feeders. Their primary food source is typically decaying organic material, such as fallen leaves, rotting wood, and other debris. By consuming this detritus, earwigs perform a beneficial scavenger function, recycling nutrients back into the soil.
The earwig’s diet also includes a significant predatory component, often overlooked when focusing on plant damage. Earwigs actively hunt and consume small, soft-bodied insect pests, including aphids, mites, and the eggs of slugs and snails. This predation helps naturally regulate populations of destructive garden pests.
Plant consumption usually occurs when earwig populations are high or when preferred food sources, like decaying matter or insect prey, become scarce. When they do turn to living vegetation, earwigs tend to seek out tender, young growth and soft fruits. This shift in diet causes them to transition from a beneficial garden helper to a noticeable pest.
The majority of their feeding activity takes place at night, which is why they are rarely seen causing damage during the day. Their adaptability to different food sources ensures their survival across various environments.
Identifying Earwig Damage in the Garden
Differentiating earwig damage from that caused by slugs, snails, or caterpillars can be challenging but is possible by noting specific visual cues. Earwigs chew irregular, ragged holes in the leaves and petals of plants, often leaving a tattered appearance. They especially target soft-tissue plants and delicate flowers, such as dahlias, marigolds, and clematis.
A distinguishing characteristic of earwig feeding is the absence of a slime trail, a sign left by slugs and snails. Damage is typically concentrated on new seedlings or tender growth because older, tougher foliage is avoided. They also gouge shallow holes into soft fruits like strawberries and corn silks, preventing proper kernel development.
Inspecting plants late at night with a flashlight is the most reliable way to confirm the presence and activity of earwigs, as they hide in concealed spots throughout the day. If the damage is accompanied by tiny, black, pellet-like droppings, it further suggests earwigs or another chewing insect is responsible.
Non-Chemical Management Approaches
Controlling earwig populations without resorting to chemical pesticides focuses on reducing their habitat and using simple trapping methods. Earwigs are strongly attracted to dark, moist hiding places, so eliminating excess surface moisture and garden debris is an effective first step. This involves keeping mulch layers thin and pulling back groundcover or stones near susceptible plants.
Simple traps can be constructed using materials that mimic their preferred daytime shelter. A piece of rolled-up damp newspaper, a short section of garden hose, or a piece of corrugated cardboard placed near damaged plants will attract earwigs seeking shelter. These traps can be collected each morning and the insects removed from the garden.
Another effective method involves oil traps, made by burying a shallow container, such as a tuna can, with the rim flush to the soil surface. Filling the can with vegetable oil and a drop of dish soap attracts the earwigs, which fall in and cannot escape. Applying diatomaceous earth, a fine powder made from fossilized organisms, around the base of plants also provides a non-toxic barrier that dehydrates the insects upon contact.