Earwigs

"Bugs are not going to inherit the earth. They own it now.
So we might as well make peace with our landlords."
- Thomas Eisner

introduction

Earwigs are members of the insect order Dermaptera, and are mainly identified through the large forceps at their back ends. They have wings, which they use very rarely to fly. They are found on all continents except for Antarctica. They are mainly nocturnal creatures, preferring to hide in small moist crevices in garden spaces during the daylight hours. They are abundant in many climates, though few can survive winter outdoors, especially in cooler climates. Most are flattened insects, allowing them to fit into tight spaces, such as under the bark of trees. The largest species reaches up to 2 inches long. Their intimidating forceps are used for holding prey, defense, and copulation. They are seen as beneficials in gardens, providing food for birds, amphibians, mammals, lizards, centipedes, assassin bugs, bats, and spiders. They are also eaten by species of fish when they fall into bodies of water.

Earwigs have biting mouthparts, compound eyes, and antennae that are segmented. Although they may not be the most attractive house-mates, these insects are not harmful to humans and do not vector any diseases. Their curved forceps cause little or no harm to humans. They do not typically climb into the ears of humans, as they are rumored to do, and definitely do not lay their eggs inside of the human body. They are popular insects in literature and folklore, but do not live up to their reputation as malicious organisms.

Earwig Behavior

Most species of earwig are nocturnal, and during the day live in small crevices, leaf litter, bark, and fallen logs. There are some species that are blind and live their entire lives in caves. They typically feed on a wide array of living and dead plant and animal matter. They are mostly scavengers, and do not typically actively hunt for food, though there are some notable species that do. In fall and winter, females will dig cells in the ground, where they lay masses of eggs (between 20 and 80). After about seven days' time, the eggs hatch into small, light brown nymphs, remaining in the cell their mother provided for them until they molt for the first time. Part of the earwig population in most landscapes hibernates during the winter as pairs buried in cells in the soil, though in mild climates, they can remain active year-round. These critters feed on a wide variety of living and dead items, including insects, mites, and shoots of plants. They consume aphids in large numbers, as well as any insect eggs they can find.

Female earwigs care for their young, feeding, cleaning, and protecting them until they have grown.

Before laying eggs, Earwigs will dig a burrow or find a safe space.

Earwigs are considered pests of some plants, especially those with soft, accessible fruits.

Earwigs, though considered to be non-social insects, exhibit maternal care to their young. The mother will pay close attention to the needs of her eggs, such as warmth and protection. She defends her eggs from any hungry predators, and does not leave their side even to eat. She also cleans the eggs periodically to keep them free from fungi and bacteria. Nymphs, once out of their shells, eat their egg casing and continue to live with their mother, fed regurgitated food. Adult earwigs in some species have the ability to defend themselves by spraying a foul-smelling liquid from scent glands on their abdomens.

Earwig Species

Anisolabis maritima
(Maritime Earwig, Seaside Earwig)
Widespread distribution worldwide; occurs along coastlines. Originally from Asia, these Earwigs reach up to 1.2 inches and are grey-black with yellow legs.

Chelisoches morio
(Black Earwig)
These omnivores are common in tropical areas, but are present worldwide. They are jet black, and up to about an inch long.

Doru aculeatum
(Spine-Tailed Earwig)
Found in woods and grassy areas, this species is attracted to outdoor lights at nighttime. Brown body with pale markings.

Doru lineare
(Linear Earwig)
Yellow forewings and reddish-brown bodies. Typically found near water in grasslands and sedges.

Doru taeniatum
(Lined Earwig)
Found in the Americas, with yellow and dark brown bodies.

Euborellia annulipes
(Ringlegged Earwig)
Dark brown to 0.4-1 inch long. Legs pale brown. Dark band around the middle of the femur.

Euborellia cincticollis
(African Earwig)

Forficula auricularia
(European Earwig)
Reddish-brown insects with slender antennae. To 0.6 inches long.

Labia minor
(Lesser Earwig)
To 0.3 inches long, with chocolate brown body and yellow legs and antennae.

Labidura riparia
(Shore Earwig, Tawny Earwig)
These earwigs range from 0.6 to 1.2 inches long, and are tan to reddish brown with various markings. Unpleasant odor when crushed.

Marava arachidis
(Bone-House Earwig)
Found in many areas of the world, these earwigs inhabit the stems of fennel and lay eggs on the leaves.

Marava pulchella
Found in the Caribbean and North America.

Vostox apicedentatus
(Toothed Earwig)
Found in Central America and North America.

earwigs in the garden

Earwigs are very recognizable garden critters, and although they can do some damage to crop species grown in veggie gardens, soft fruit and annual flowers, they are also considered to be beneficials, consuming garden pests such as aphids. Although they may look threatening, earwigs are totally harmless to humans and pets, and do not need to be removed from gardens for safety purposes. If populations get too large, however, they can cause some serious damage to plants. To manage earwigs, follow these guidelines:

Eliminate Hidey Holes
These organisms hide during the day, preferring to spend their time in moist, dark places in the garden. They can be found under the bark of trees or under potted plants or other patio furniture. They also hang out in leaf litter close to the ground and amongst dense groundcovers such as ivy.

Set a Trap
Earwig traps are typically made from old cat food or tuna fish cans filled with about an inch of oil. Fish oil or vegetable oil with a few drops of bacon grease attract the earwigs, who will come to investigate and fall into the oil. These traps are most effective when they are somewhat buried, so that the height of the sides of the can is not too tall for an earwig to scale easily. Hide traps throughout the yard, against fences, near shrubs, or amongst groundcover.

Here Today, Gone Tomorrow
Another type of trap commonly used to collect and dispose of earwigs are items that provide earwigs with their desired resting space during the day. This includes rolled up newspapers, bamboo tubes, corrugated cardboard, or a short piece of hose. Place traps on soil near plants that earwigs frequent at dusk, and the next morning, pick up the trap and shake it over a pail of soapy water.

Encourage Natural Enemies
Many organisms eat earwigs as snacks throughout the day, including toads, birds, lizards, and even small mammals. Chickens and ducks, if allowed to roam the garden, will also help to control these critters if they get out of hand. Encouraging these animals to come into the landscape is key in preventing earwig populations from getting out of control.

Defend the Fruits
Earwigs have a proclivity for soft fruits like peaches, and will climb trees to get to them if there aren't any that have dropped to the ground. To discourage this behavior, keep the bases of fruit trees clear of debris and suckers. On the lower trunks of older fruit trees where the bark is beginning to come up, remove the bark so that the earwigs do not have a convenient hiding place to shelter during the day. Trunks of trees can also be treated with sticky substances that trap insects, preventing them from climbing up and reaching the ripening fruit. Earwigs are beneficial in trees, especially when they are feeding on other pest species, so make sure to only take these precautions with your soft fruit trees.

For more non-chemical options and natural pest control methods, consult the Pests and Pest Management page:

Pests & Pest Management