Earwigs: Friend or Foe?

Ennemies in North America, But Friends in Europe

Here’s the answer I gave to a reader of my newspaper garden column in 2002 who wrote with a question about earwigs. And 20 years later, I feel the advice still holds. In my own garden, now 30 years after the original invasion subsided, earwig numbers have remained small and they never do more than a bit of minor damage.

Larry Hodgson

Question:

My mother has a serious earwig problem in her garden. There are thousands of them! They eat all the annuals and perennials. After a one-night passage, only the veins remain. They even destroyed the marigolds she planted and that were supposed to repel them! She tried treating with rotenone, then all sorts of traps. Several kill a few earwigs, but the next night, they’re back and as numerous as ever! They damage all the annuals as well as the cucurbits. What should she do? This is the second year that the situation has been so serious.

Martine Létourneau,
St-Roch-des-Aulnaies, Québec

Answer:

The earwig, introduced to North America from Europe, is a new insect in your region. What you’re seeing is the result of a population explosion that always seems to occur when it first arrives in a new territory. It proliferates massively, to the point of causing terrible damage. And any treatment is a waste of time, because no matter how many you kill, the dead ones are immediately replaced by even more.

Earwig Treatment?

True enough, if you check online, you’ll find dozens of treatments you can use to kill problem earwigs . . . and they all work. Among them you’ll find:

1. Catching them in half-closed empty sardine tin (they are attracted to the odor of oil and like to hide in its shade);
2. Spraying them with insecticidal soap;
3. Leaving an upside-down pot filled with straw where they can hide during the day (so you can shake them into a pot of soapy water to drown);
4. Leaving out a rolled-up newspaper that they can hide in and you can shake them free of;
5. Stand a broom upright outdoors so they can hide in the bristles, then shake them free and stomp on them.
6. And the list goes on and on.

The More You Kill, The More There Are!

But the point is, the more you kill, the more there are. They arrive in droves from your neighbors! It’s so discouraging that some people consider giving up on gardening!

Then things calm down. No one knows why, but after two or three summers of horror, the population crashes, and everything goes back to normal. Well, near normal. True enough, you might see a few nibbled leaves, flowers or fruits. And sometimes you’ll find a dark corner with a cluster of them hiding out together, but they no longer do much damage.

Rather, they resume the role they play in their native Europe, that of voracious predators of plant pests such as aphids, insect larvae and slugs. And can you really complain of an insect that reduces your garden’s slug population?

I recommend that you encourage your mother to be patient. During the summers of earwig abundance, she should simply avoid the plants that earwigs love, and that includes many but not all annuals and some vegetables. And plant more of the plants earwigs avoid… And you’ll discover there are hundreds of them, because, no, they don’t eat everything. When the infestation does subside, and that day will come, she can return to the plants she used to grow.

In my own garden where, ten years ago, I thought I would never be able to grow lettuce, gladiolus, black-eyed susans or dahlias again, I can now grow whatever I like. True enough, I still occasionally see little gatherings of earwigs, especially when I move an object left lying on the ground (they love hiding in dark places). However, there is no more than minor damage, so I now pretty much ignore them.

Fierce Predators

If we North Americans hate earwigs to the point of wanting to annihilate them, in Europe, the situation is quite the opposite. They’re considered beneficial!

Europeans even go so far as to attach small boxes punched with holes or inverted terra cotta pots stuffed with straw onto fruit trees to serve as earwig homes, largely because they are such are fierce predators of the aphids that regularly devastate their crops.

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Earwigs: rather than panic and call them foes, why not learn to make them your friends?

More Here: Earwigs in Your Barbecue? Here’s What to Do!