Overview
Lined earwigs are nocturnal insects that feed on a variety of materials, including decaying organic matter and living plant tissue. While they can be beneficial as scavengers, they may also damage seedlings and soft foliage when populations are high.
Their dual role as both beneficial and pest species makes them an interesting subject in pest management. They are often found in moist environments and shelter during the day in cracks, soil, or debris.
They connect to broader pest categories such as Garden Pests.
The Striped Scavenger: Lined Earwigs
The Lined Earwig (Doru taeniatum) is a distinctive member of the earwig family, easily recognized by the two pale, longitudinal stripes running down its dark wing covers (elytra). While many earwigs are viewed strictly as garden pests, the Lined Earwig occupies a more complex ecological niche, often acting as a beneficial predator in agricultural systems like corn and cotton fields.
Physical Characteristics and Behavior
Growing to about 12mm to 15mm in length, these insects possess the characteristic “forceps” or cerci at the end of their abdomen. In males, these forceps are strongly curved, while in females, they are straighter. Unlike the common European Earwig, which is often found in damp basements, the Lined Earwig prefers the whorls of plants, particularly corn, where it hides during the day.
A Friend or Foe in the Garden?
The Lined Earwig is an omnivore, which makes its impact on a garden or farm somewhat dual-natured:
- Beneficial Predator: They are voracious hunters of small, soft-bodied pests. They are particularly effective at controlling populations of Fall Armyworms and various species of aphids and mites.
- Occasional Pest: If their primary prey is scarce, they may turn their attention to the plant itself. Damage usually appears as ragged holes in the silk or young leaves of corn, though this is rarely economically significant compared to the pests they consume.
- Nocturnal Activity: Like all earwigs, they are most active at night, using their forceps to defend territory and capture prey.
Management and Encouragement
In most cases, Lined Earwigs should be encouraged rather than eliminated, especially in integrated pest management (IPM) programs. They are sensitive to broad-spectrum insecticides, so using targeted treatments for other pests helps preserve these natural predators. If they become a nuisance inside a home, the best strategy is exclusion: sealing cracks in foundations and reducing excessive mulch or moisture near entry points, as they are naturally drawn to damp, dark crevices.
Damage
- Chewed leaves and seedlings
- Damage to soft plant tissue
- Irregular holes in foliage
Management
- Reduce moisture and shelter areas
- Remove debris
- Use traps if necessary