Pincher bugs (earwigs) are common garden pests that shift from beneficial decomposers to destructive feeders when their population explodes. These insects thrive in dark, moist environments, and their nocturnal feeding habits cause significant plant damage. Managing these populations requires a combined strategy of active trapping, modifying the garden environment, and applying targeted treatments.
Identifying Pincher Bugs and Assessing Garden Damage
The European earwig, the most common species, is easily identified by its reddish-brown, elongated body, typically measuring about three-quarters of an inch long. A defining feature is the pair of prominent, pincer-like appendages, called cerci, located at the end of the abdomen. The male’s pincers are noticeably curved, while the female’s are straighter and thinner.
Earwigs are primarily active after sunset, seeking shelter during the day in cool, damp locations. Damage often appears as irregular holes in leaves and flower petals, which can be mistaken for slug or snail feeding, though earwigs leave no slime trails. They also chew on tender seedlings, corn silk, and soft fruits like strawberries, creating shallow gouges or small, jagged holes.
Active Trapping and Non-Toxic Removal Methods
Immediate reduction of the earwig population can be achieved through trapping that exploits their preference for dark, tight daytime hiding spots. A simple method is using rolled-up damp newspaper or corrugated cardboard tubes placed near damaged plants. Earwigs crawl inside these tubes for shelter before dawn; collecting and removing these habitat traps daily will significantly reduce the population.
Another technique involves using a low-sided can or shallow container sunk into the soil so the rim is level with the ground. This pitfall trap is filled about an inch deep with vegetable oil mixed with an attractant like soy sauce or bacon grease. The earwigs are drawn to the scent, fall into the liquid, and drown. Oil traps should be checked and emptied every few days to maintain effectiveness.
Manual removal is also a viable option, especially for smaller gardens or localized infestations, since earwigs are relatively slow movers. You can go out after dark with a flashlight to find the insects actively feeding on plants. Once located, they can be brushed off or vacuumed up using a small, handheld vacuum and then drowned in a bucket of soapy water.
Eliminating Hiding Spots Through Habitat Modification
Making the garden environment less hospitable is key to control. Earwigs require consistently damp conditions to survive, so reducing surface moisture is a primary goal. Adjusting irrigation schedules to water plants early in the morning allows the soil surface to dry out before the earwigs become active at night. It is also important to improve drainage in soggy areas and repair leaky outdoor faucets or irrigation lines near the garden beds.
The removal of debris and clutter eliminates the daytime hiding spots that earwigs depend on for shelter. This includes clearing away:
- Piles of leaves, weeds, and grass clippings.
- Stones.
- Old wood or boards that sit directly on the soil.
Thinning out dense plant growth that creates deep shade and holds moisture can also disrupt their habitat.
Gardeners should examine their use of mulch. While mulch is beneficial, thick layers, especially of wood chips, can harbor large populations. Pulling mulch back a few inches from the base of plants creates a dry, exposed barrier they are reluctant to cross. In severe cases, replacing organic mulches near plant bases with materials like gravel or stone can significantly reduce moist shelter.
Applying Targeted Organic and Chemical Treatments
When physical removal and habitat modification prove insufficient, applying targeted treatments can help manage persistent populations. Diatomaceous Earth (DE) is a popular organic option. It acts as a mechanical insecticide; the fine, sharp particles scratch the earwig’s protective waxy layer, causing them to dehydrate and die. A thin layer of food-grade DE should be dusted around the base of vulnerable plants and along garden borders. Because DE becomes ineffective when wet, it must be reapplied after rain or heavy watering.
A more concentrated approach involves using boric acid, which acts as a stomach poison upon ingestion. Boric acid should not be broadcast but used in targeted bait stations, such as mixing it with a sweet attractant and placing it inside a covered container with small entry holes. This strategic placement ensures the product is kept out of reach of children and pets, which is necessary because it is toxic if swallowed.
Organic pesticides containing active ingredients like Spinosad or Pyrethrins are available for direct application to the soil and perimeter areas. Products containing Spinosad, often found in granular baits, are effective against earwigs when sprinkled lightly around affected plants. When using any chemical treatment, read the product label thoroughly to ensure safe application, especially on edible crops.