4 June 2015, written by Barbara Pleasant
Like most gardeners, I first became acquainted with earwigs (Forficula auricularia) when I moved a big clay pot and saw them scurry away from their snug spot beneath it. They were not a problem that year, or in many seasons since, but this year is different. Last week they ate a flat of cosmos seedlings and chewed several herbs I had growing on the deck, and my first head of cabbage had a gang of earwigs hiding in the outer leaves.
Im reluctant to engage in direct earwig control because they are not always harmful. While earwigs do eat leaves and fruits from a long list of plants, they also consume small soft-bodied insects. But especially in rainy years, earwigs in the garden become so numerous that they turn up everywhere and eat things you wish they wouldnt, like the poor basil below. Evidence of earwig feeding includes leaves with holes that have ragged edges, or are only partially rasped through, and a light scattering of very small black particles of earwig excrement.
Earwigs can be a nuisance in herb and vegetable gardens, munching on tender seedlings and leaves. Baby sage plants are especially vulnerable to damage from these pests. Here’s how to protect your sage seedlings and get rid of earwigs in your garden organically.
What are Earwigs?
Earwigs are nocturnal insects that hide during the day and come out at night to feed. They got their name from the pincers or “forceps” on their abdomen that resemble a human ear. These pincers are used for defense and mating rituals but are harmless to humans.
There are over 1,000 species of earwigs, but the European earwig is the most common garden pest in North America. Earwigs are omnivores and scavengers that feed on decaying plant material. But when their populations grow, they will also feed on living plants, including seedlings, flowers, fruits and vegetables.
Earwig Damage on Plants
Earwigs use their pincers to chew irregular holes in leaves, flowers and fruits. Seedlings and young plants are very vulnerable to earwigs since they lack tougher cell walls in their tender new growth.
Signs of earwig damage on sage and other plants include
- Jagged holes in leaves and petals
- Leaves look very ragged as if partially eaten
- Black earwig excrement around base of plants
- Earwigs hiding under pots and in soil during day
How to Get Rid of Earwigs in the Garden
Here are some organic methods to get rid of earwigs in your herb garden
Remove Debris
Earwigs love dark, damp places to hide during the day. Remove piles of dead leaves, mulch, boards, stones and other potential shelters near your plants.
Avoid Overwatering
Earwigs thrive in moist conditions. Allow the soil to dry out between waterings and avoid heavy mulching.
Use Traps
Place rolled up cardboard or bamboo tubes on the ground near plants. Earwigs will crawl inside to hide during the day. Shake them out into soapy water to kill them.
Use Diatomaceous Earth
Sprinkle food-grade diatomaceous earth around plants to kill and repel earwigs. It cuts their waxy coating so they die of dehydration. Reapply after rain.
Spray Rubbing Alcohol
A spray made from equal parts 70% rubbing alcohol and water will kill earwigs on contact. Test on one leaf first to ensure the plant can tolerate it.
Grow Pest-Repellent Plants
Marigolds, chives, garlic and other aromatic herbs repel earwigs. Interplant them with your sage.
Attract Natural Predators
Toads, birds, spiders and ground beetles all prey on earwigs. Create habitat to attract them to your garden.
Use Sticky Barriers
Petroleum jelly, sticky traps or duct tape coated in glue around pots prevents earwigs from climbing up to feed at night.
Check Potted Plants
Earwigs hide under pots during the day. Use pot feet to prevent this or dunk pots in water to flush them out before bringing indoors.
Protecting Baby Sage Plants from Earwigs
Baby sage plants are most vulnerable to earwigs right after germination as their first true leaves emerge. Here are some tips to protect them:
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Plant sage seeds in containers or raised beds to prevent earwigs from hiding in soil.
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Wait to transplant seedlings until they have 4-6 true leaves and sturdier stems.
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Surround seedlings with a ring of diatomaceous earth to prevent earwigs from reaching them.
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Use cut soda bottles or plastic guards around seedlings as a physical barrier.
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Keep soil moist but not soggy to deter earwigs from laying eggs.
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Sprinkle crushed eggshells around seedlings as a sharp natural mulch earwigs won’t cross.
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Check under pots and containers for hiding earwigs. Dunk in soapy water.
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Handpick any earwigs you see at night with a flashlight. Drop in soapy water.
With vigilance and these organic methods, you can protect vulnerable baby sage plants from earwig damage. Maintaining a balanced ecosystem with natural predators and pest-repellent plants will also help keep earwig populations in check.
The Earwig Ick Factor
Some people are unreasonably icked out by earwigs, in part because they look so threatening. In fact, gardeners who take snakes and spiders in stride are sometimes fearful of earwigs. Originally from Europe, the common earwig has spread to temperate climates throughout the world.
Personally, you have nothing to fear from earwigs. The pincers on their hind ends are used for mating, not biting, and they dont get into peoples ears. Emergency room records indicate that another insect (rhymes with coach) is the bad one. And consider: earwigs in the garden inhabit the moist, dark world of plants and pots and mulch outdoors, and should they come indoors at all it would be to set up housekeeping in a basement rather than a bedroom. In her book, The Earwigs Tale, writer May Berenbaum notes that “the reluctance of earwigs to fly would seem to reduce the probability of their gaining access to the ears of anyone who doesnt habitually sleep with his head jammed into basement corners.”
Wherever they are, earwigs are easy to trap in homemade traps as long as you choose the right method for the job. Earwigs feed at night and gather in sheltered places during the day, so most earwig traps use attractive habitat, or refuge, as their lure.
The exception is the oil pit trap, developed by entomologist Whitney Cranshaw. The best earwig trap to use in the open garden, an oil pit trap is simply a small plastic container with lid, with an entry hole cut in the lid. When baited with canola or olive oil, with a little bacon grease, fish oil or soy sauce sprinkled in for aroma, and sunk into the garden so the lid is flush with the surface, one of these earwig traps can clean up a cabbage patch fast. You wont catch innocent victims, because earwigs are the only garden creatures attracted to the traps, which will need to be emptied and refilled every week or so.
Another good way to trap earwigs in the garden is to roll lightly dampened newspapers into hollow tubes, tie them with thread or lightweight cotton string, and place them among plants that are under attack by earwigs. After a few days the earwigs will set up housekeeping in the newspaper tubes, which can be gathered up and composted. Short pieces of hollow bamboo the thickness of your finger can be used in the same way.
A similar reusable earwig trap can be made by placing plastic drinking straws inside a piece of plastic pipe. Earwigs seem to like plastic though it provides no purchase for their little feet. A couple of taps into a bowl of soapy water, and the earwigs come tumbling out of a drinking straw trap.
Earwigs can become persistent pests of peaches and other tree fruits, in which case cardboard earwig traps tied to trunks and lateral branches are in order. But you dont want to catch all of the earwigs, or at least not until late summer. Until then, research from Utah State University shows that earwigs do more good than harm by eating aphids and other small insects. But when fruits start to soften with ripeness, earwigs can become a problem.
To trap them, all you will need is some corrugated cardboard and strips of cloth to tie the traps to branches. Scientists use one-sided corrugated cardboard, which you can make by wetting one side of a piece of corrugated cardboard, and then prying it off. Make into a small roll, and fasten to trunks and major limbs. Install earwig traps a month before the fruit is expected to ripen, and replace once a week.
As for me, after this years losses, I will take more care to disinvite earwigs to the area where I grow my seedlings. Earwigs stick together in groups, and I found the ones that were eating my seedlings hiding in the dry crevices between plastic pots and the trays used to hold them. It was a perfect set-up for them – rest under the moist pots during the day, come out and eat tender young leaves at night with no aggravation from frogs and other predators. Oops, my mistake.
Plants Related to this Article
If you need help designing your vegetable garden, try our Vegetable Garden Planner.
How to Get Rid of Earwigs
FAQ
How to remove earwigs from plants?
Do coffee grounds repel earwigs?
What causes earwigs in plants?
What do earwigs hate the most?
How do I get rid of earwigs in my garden?
Oil pit traps are a great remedy for earwigs. Combine equal parts soy sauce and olive or vegetable oil, put it in a small plastic container, and secure the lid. Punch holes in the top of the container, near the lid. Make the holes large enough for the earwigs to get in. Bury the container in the soil just up to the holes.
How do you catch earwigs in a garden?
Adults overwinter under garden debris, stones, and boards as well as in soil. To trap earwigs, you can fill cat food cans (or other similar cans) with ¼ inch of oil (preferably fish oil) and sink them into the ground near plants.
How do you get earwigs out of a container?
Punch holes in the top of the container, near the lid. Make the holes large enough for the earwigs to get in. Bury the container in the soil just up to the holes. The soy sauce will attract the earwigs, and the oil will prevent them from escaping.
Do earwigs damage garden crops?
A large earwig infestation can damage garden crops. As a result, it is necessary that you get rid of them if you spot many of these pests. Earwigs (pincher bugs) fall into the insect order Dermaptera [ 1 ]. They are found everywhere but Antarctica because they can’t handle the cold. They are dark brown to reddish-brown and have long, flat bodies.