Sunday, September 21, 2008

Trickery and Sex in the Firefly World

This is not news in the scientific world, but it’s news to me—I ran across this in some reading I have to do for a seminar tomorrow. Further evidence that bugs are awesome:

Fireflies, lightning bugs, or Lampyrids (if you were the nerdy type). Who didn’t spend innumerable summer evenings in childhood chasing after these beetles, empty pickle jar in hand? But you might not have known of the high drama and Shakespearian trickery that was going on among these insects right there in your own childhood backyard.

There’s multiple species and genera of Lampyrids in North America, each with its own characteristic flashing pattern. Males and females of the same species locate each other for mating using these unique signals. However, females of the genus Photuris have evolved a deadly trap: they lure males of other genera by imitating their own females’ flashes. When the males come a-courtin’, the Photuris females pounce, and devour them with gusto.

You may wonder how the Photuris females ever mate, if they’re always on the prowl for dinner during mating time. Turns out that male Photuris capitalize on their female’s predilection for firefly meat by imitating the flashing patterns of males of other genera—the very insects that the female is trying to lure to their death! Some Photuris males go even farther in their imitation, by flashing not only the right pattern, but also at the right time of night, in the right location, to be even more convincing as the potential prey.

In some species of Photuris this imitative behavior has gone so far that the species has completely lost the ability to produce its own unique flashing pattern, instead conducting all its business using signals stolen from others.

I’m unaware of any papers that detail what happens next, after the flash exchange—how does the male Photuris end up as the mate, and not the dinner of the female? I’ll do some more searching because this has piqued my interest, and let you know if I find an answer.


Anonymous said...

vicious. i like it. around april of this year, i was reminiscing about wonderful summer weather in vt and watching the fireflies dance. so i urged my co-worker to head to the smokies while on a business trip which miraculously coincided with the two-week Photinus carolinus synchronous flashing. here are his shots:

Susan Johnson said...

wow, amazing pictures!! i don't recall the fireflies back home in illinois being synchronous--this looks like quite a show!
more reason for me to head up to vermont to visit...