Earwigs Are Not…

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…brain-burrowing terrors from a horror movie! Nonetheless, most people find them pretty creepy looking, and commonly confuse them with two other pests: firebrats and silverfish.

In folklore, earwigs came out at night and crawled into the ears of sleeping people. Once in the ear, people believed the creatures bored into the brain. The fact that earwigs often hid in the powdered wigs of eighteenth century ladies and fops merely bolstered their fearsome reputation. However, despite their sinister appearance and scary reputation, they have no brain sucking or ear invading intentions.

Basic Earwig Anatomy

  • Claw-like forceps called cerci protrude from the end of the abdomen (males’ are more curved)
  • Approximately ½ to 1¼ inches in length
  • A segmented, soft body with a head, thorax, and abdomen
  • Dark reddish-brown body color, although some species are brown or black
  • Flat, elongated shape
  • Six brownish yellow legs
  • May have wings or forewings

Earwigs in Arizona

There isn’t just one earwig; there are many! Although there are numerous species of these insects, the most commonly encountered type in Arizona is the Forficula auricularia earwig, or European earwig, which is an introduced species. All earwigs are omnivores and eat plants and other insects. Earwigs sometimes cause problems for certain garden plants, ornamental plants and some types of small trees. In Arizona, they may enter houses to seek out moisture. However, earwigs normally hide in dark, moist areas such as under potted plants or mulch.

Earwig Imposters

People often confuse earwigs, silverfish, and firebrats. Properly dealing and eradicating a pest problem requires knowing the creature you are up against.

You may have silverfish if:

  • The bug is ¼ to ½ inch long
  • It has three appendages (about the same length of the body) that look like tails attached to the abdomen
  • The bug’s body is a uniform silver color
  • It has no wings
  • It has a soft, oval, and flat body that really quite resembles a fish

You have firebrats if:

  • The bug is ¼ to ½ inch long
  • It has a body that is thicker at the front and narrower in back
  • It lacks wings
  • It has three appendages (about the same length of the body) attached to the abdomen that look like tails
  • Its body is a mottled grayish-brown color

There are other things that all three creatures have in common, such as antennae and six legs, but discerning the differences in those parts requires a closer inspection than most people are willing to undertake.

If You Cannot (or Will Not) Get Close Enough to Make a Visual Identification

Lack the desire to inspect the fine details of the creature at hand? Sometimes looking at its behavior helps identify them.

  • Does it fly? It may be an earwig.
  • Does it run in short spurts of movement interspersed with quick stops? It may be a silverfish or firebrat.
  • Is it unable to climb smooth vertical surfaces (such as sink or tub walls)? It could be a silverfish or firebrat.
  • Can it scurry up a rougher vertical wall? It may be an earwig.
  • Is it in a dry area? It could be a silverfish or firebrat, as they prefer dryer conditions
  • Does it shelter in dark, moist areas (under stones, boards, sidewalks, or soil) during the day and is active at night, it may be an earwig

Know the Bug By What It Eats

Earwigs do eat other bugs, but they also have a taste for some favorite garden plants, including:

  • Beans
  • Butterfly bush
  • Corn silk
  • Dahlias
  • Hollyhocks
  • Lettuce
  • Marigolds
  • Potatoes
  • Roses
  • Squash
  • Strawberries
  • Zinnias

If you find a bug eating books or other paper materials, it is probably a silverfish or firebrat. They prefer food that is high in protein, sugar, and starch. This means you can often find them eating (read: destroying):

  • Book binding
  • Cereals
  • Fabrics: cotton, linen, and rayon
  • Grains
  • Wallpaper paste and sizing

Which Ones Are Worse?

Silverfish and firebrats are the bane of book collectors. As previously mentioned, if the damage is to books, fabrics, and other dry, cellulose-based materials, firebrats and silverfish are the likely culprits.

Earwigs pose problems for certain plants, such as soft fruits and certain flowers. However, they also eat harmful garden insects like aphids.

A Word About those Pincers

The pincers, or cerci, are actually sensory organs, and earwigs use them to feel things and to groom themselves. However, they also use them for defense and capturing prey. Some swear they experienced excruciating pain due to an earwig pincer pinch—but even if an earwig bites, the most you would feel is a little pinch and nothing more.