Archive | 11:59 pm

The Common Earwig

7 Jan
Male earwig (Forficulidae) in leaf litter.

Male earwig in leaf litter (San Diego, California).

Here’s some more shots of the earwigs I came across flipping stones during the ESA conference in San Diego.  We mostly only see the small, wingless Anisolabididae in my area so I was unreasonably impressed and excited by these common or european earwigs (family Forficulidae).  Nonetheless, these are interesting little insects to take a closer look at.  Aside from the females guarding eggs and nymphs, it was also interesting to observe the range in sizes of the cerci, which are adapted into pincers in earwigs.  Starting with the short straight pincers of the female earwigs, these cerci ranged from similarly sized but curvier pincers in the males to large curved scimitars nearly twice as long.

The cerci of male and female common earwigs (Forficulidae).

Male and female common earwigs (Forficulidae).

These earwigs are fairly easy to handle, being generally unaggressive towards humans.  When threatened, they may attempt to pinch with their cerci, but rarely have enough of a grip to do any damage.  However, I did manage to acquire a war wound while playing with these fellows.  One of the males caught my finger in a particularly vicious pinch and actually drew blood with his cerci.  Since my brain has been warped by entomology I reacted by being impressed and interested.  I went around showing my finger to my fellow entomologists and asking if they knew earwigs could do that (they were universally surprised).

Of course, I took the moral of the story not to be “don’t handle earwigs” but more of a “be careful with sharp objects.”  Even peaceful cicadas have been known to get in a chance stab with their proboscises.  On the whole I’ve found it’s much more useful (and entertaining) to know where the sharp bits are and how to avoid them.

Male common earwig on hand (Forficulidae).

A male earwig held in hand.