One of the many, many reasons I love insects is that they are just plain weird and kinky.
(What? I don’t think that implies anything about my personality!)

Today, we look at earwig mating habits. Here’s your water-cooler trivia for the day:
Earwigs have two penises–in case one is broken off.

Kamimura, Y., & Matsuo, Y. (2001). A “spare” compensates for the risk of destruction of the elongated penis of earwigs (Insecta: Dermaptera) Naturwissenschaften, 88 (11), 468-471 DOI: 10.1007/s001140100259

“In Dermaptera (earwigs), males ….have paired, elongated male intromittent organs (virgae)…..Several authors have assumed that one of the paired virgae is non-functional, because it points in the “wrong” direction. We investigated the mating success of handicapped males of Euborellia plebeja in which one of their paired virgae was removed experimentally. These handicapped males succeeded in inseminating a mate. Males with genital damage are found in the field, suggesting that the “spare” functions under natural conditions.

This was a very well done study–in addition to earwig coitus interruptus in the lab, they also spent some time in the field, verifying that males are often disturbed with schlong-snapping results.

That’s how they came up with one of the more unusual primary research sentences I’ve seen:

“When the abdomen of mating males was pinched and they were gently lifted with forceps, 75% of males lost one of their virgae.”

Granted, I’m projecting. But….OW.

This becomes even more cringe-inducing when you know that each earwig penis is about as long as their entire body.

While I have reduced this research to Beavis and Butt-head levels here, this author’s work is a fascinating case study in evolution.  In subsequent work, he found that related earwig taxa may have lost their extra penis when they became “right-handed.”

Kamimura, Y. (2006). Right-handed penises of the earwigLabidura riparia (Insecta, Dermaptera, Labiduridae): Evolutionary relationships between structural and behavioral asymmetries Journal of Morphology, 267 (11), 1381-1389 DOI: 10.1002/jmor.10484

Fascinating stuff!

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Posted by Gwen Pearson

Writer. Nerd. Insect Evangelist. Have you heard the good news? BUGS!


  1. Yay! Penises as long as ones bodies! Too bad they have to get snapped off!

    Would they ever get separated like that in the wild?

  2. Rodrigo–yes. That was the second part of the study, where they went into the wild and collected males. (as well as disturbing them in copulo.)

  3. Great Caesar’s Ghost – how I love entomology! This one gets Stumbled for certain.

  4. Here’s to the Earwig, that most God-blessed critter
    Whose loss of his penis don’t make him bitter
    Cause nature has blessed him with two shlongs for sowing
    I guess one is for comin’ and one is for going!

  5. Now there’s a headline I’ve never seen before!

  6. I’ve never seen poetry dedicated to earwig penii before, either.

  7. “virgae” and not aedeagi?

    I’m sorry, but if you’re snapping off a critter’s penis, it’s probably not being “gently lifted” … Just a hunch.


  8. Lawrence–Well done! :D

    And Andrea–it’s a break-away penis. Like they use in Hollywood for stunts.

    Er. You know what I mean.

  9. I think I saw that film..

  10. I used to be interesting in insects’ world too…by knowing them we can keep their existence and make this world better

  11. You have to wonder what set of environmental stresses led to this point.

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