the ultimate crevice bug

April 12, 2006

in Insects,Natural history

This week I’ve been trying to finish up some especially obnoxious paperwork on a project before my field season begins in earnest.  Since I’m annoyed, I thought I’d take a little break and write about an annoying creature: the earwig.

I find earwigs just repugnant.  I don’t know why. While not attractive, they are less disgusting-looking than any number of other invertebrates that I don’t find objectionable.  Despite the ominous curving cerci (the forceps-like abdominal appendage), they are harmless.  The story that they get in your ears and bore into your head is an old wives tale.

There are several species of earwig in Michigan, but the most common is the European earwig, Forficula auricularia, a non-native species (I hesitate to name the other another exotic earwig found here, for fear of the Google traffic it will bring me, but, what the hell — it’s Labia minor).  European earwigs were introduced into North America around 1912, and they are now pretty ubiquitous in gardens and just about any other humid, mulchy place across the eastern U.S.  Their nastiest habit in my garden is rose petal munching.  All in all, pretty benign.

The Michigan earwig fact sheet notes: “European earwigs can be kept in captivity with a minimum of care. Although few people are fond of earwigs, they can be interesting to watch and easy to care for.”  In the interest of full disclosure, the author of this page is a good friend of mine, and as such is pretty offbeat.  Still, I didn’t think he was so strange as to recommend earwig husbandry.

Turns out that observing earwig family life, while not gripping, is at least a mildly intriguing. Females clean, rearrange, and defend their eggs.  For a short period, she will also bring food to the young nymphs, or regurgitate food for them.  These behaviors are fairly unusual in a non-social insect.

I’d be remiss writing about earwigs without mentioning the world’s largest species, at nearly 3.5 inches, the endangered (or extinct) Labidura herculeana. It is endemic to the U.K. island of St. Helena, where Napolean Bonaparte spent his last years in exile. The last live St. Helena’s earwig was seen in 1967, but a piece of cerci was found in 1995, at which time St. Helena produced its second earwig postage stamp, shown here.  For you topical stamp collecting fans, there have been, somewhat remarkably, at least seven earwig stamps issued in the world, awaiting placement in your album.

Several further searches have failed to find any living L. herculeana on St. Helena. Like many islands, it has a high rate of endemism, including 49 endemic plants, 13 ferns, 400 invertebrates (check out the St. Helena spiky yellow wood louse), and 6 birds, only one of which survives today — the St. Helena Plover, a.k.a., Wirebird.  The unique flora and fauna have suffered from habitat destruction and introduced animals. In the case of the earwig, it is presumed that habitat loss, predation by rats, and competition from the introduced giant centipede Scolopendra morsitans contributed to its demise.  To add insult to injury, the struggling island endemics are now threatened by a proposed airport.

My break time is over, and I’ve succeeded in not only distracting myself from my aggravating paperwork, but my venting has led me to a grudging appreciation of the order Dermaptera.  Although I still think they’re gross.

Image: Wikipedia Commons.


{ 12 comments }

Anonymous April 13, 2006 at 9:10 am

Nuthatch– about earwigs, is it the way they move (that bothers you)? They are a little freaky, but the chickens like to eat them. As soon as I pick up a water dish or someplace where they're hiding, the chickens rush over to snap them up. Thanks for all the great info. What is your bug? (for your "field season")… I also liked your about me list.

Nuthatch April 13, 2006 at 9:21 am

My favorite insects are dragonflies, and I do field work surveying for them in my "spare" time, but often concurrently with my bird work. My field season goes into high gear next week with bird banding. Stay tuned.

John April 13, 2006 at 1:07 pm

I don't think I would want to have anything to do with a spiky yellow wood-louse.

Jay April 13, 2006 at 1:54 pm

Well Nuthatch, I've got the perfect follow up to your post.

In Ecuador, while on a mammal expedition taking lots of specimans, just about every single rodent we worked on had Dermapteran ectoparasites. Neither I, nor the person I was with had ever seen that before.

So if you were a rodent in the tropics, you would probably view them even less favorably.

Nuthatch April 13, 2006 at 8:21 pm

Jay — I did read about a species that fed on "rat scurf, without apparent harm to the rat" as well as a species that specialized in parasitizing bats.

I have a lot to be grateful for. They don't even go for my ears.

Cindy April 13, 2006 at 10:21 pm

I've always had an aversion to these guys- think I'd rather have a slug stamp than an earwig stamp.

Suzanne April 14, 2006 at 7:16 am

I once got my apartement temporarily infested with 'earwigs' because we had a fireplace in there and had stack indoor some wood that was infested with those insects. The fireplace happen to be in the bedroom, so we had some pretty restless nights for a while. I never repeated that mistake. The wood stayed on the back porch, rain or shine. LOL

endment April 15, 2006 at 8:58 am

We have very few earwigs here – said with much gratitude…
We fought them day and night when we lived in the Sacramento California valley… not only did they do a great deal of damage to small plants in the garden, they were impossible to keep out of the house. All the children in the neighborhood learned "the earwig stomp" I like the stopm better than the stamp.

Mark O'Brien April 17, 2006 at 1:13 pm

Ok, I am with you on the ick factor. Here I am, an entomologist for 30 years, and I still think earwigs are icky. Must be those butt pincers they have…

Modulator April 21, 2006 at 11:13 am

Friday Ark #83

We’ll post links to sites that have Friday (plus or minus a few days) photos of their chosen animals (photoshops at our discretion and humans only in supporting roles). Watch the Exception category for rocks, beer, coffee cups, and….? We will add you…

pmit April 22, 2006 at 12:58 am

What I remember about earwings from my childhood in the south, is the smell. When crushed, the emit a strange unmistakeable odor, chemically yet also rotting-food like.

K T Cat May 12, 2006 at 6:04 pm

Earwigs! Too horrible to contemplate.

Comments on this entry are closed.

Previous post:

Next post: