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
You may also be interested in:
- King Missile: Detachable penis (video)
- Evolution of asymmetry in arthropod genetalia (A schwing to the right or left is apparently not unknown in the Arthropod world)
- Genitalia: An entomological obsession