First, when there’s nothing but a slow glowing dream that your fear seems to…wait a second.  I’m not actually going to provide all the lyrics.  This post isn’t about Flashdance, anyway, it’s about fireflies.  I went for a walk this evening and kept walking in and out of fireflies dancing back and forth across the sidewalks.  The amount of activity was truly impressive, all to the sounds of the first of the summer cicadas.

As I was walking, I did wonder which individuals were male and which ones were female.  My knowledge of firefly biology is not too extensive.  Both males and females flash in order to attract mates.  After mating, the female will lay eggs that eventually hatch into larvae.  They may go through several different larval stages (the number of stages depends on the species) before developing into a pupae- a glow worm.  That pupa feeds largely on other insects and earthworms.  It may take two to three years to go from egg to adult form.  Adults generally live only 2-4 weeks.  So these fireflies dancing around the neighborhood are sort of in a hurry.

All this information brings me back to the unknown…are males and females doing different things?  Well, yes and no.  Females are often more likely to flash their signals from a bush or branch, but they do fly and will flash in flight.  Males are more likely to be flashing out in the open, trying to find a female.  A flash from a male will trigger a flash (or two) from a female.  The female’s response actually allows the male to change direction and find her.  Now this point is where differences can be found in the fireflies that are flying around.  Males CHANGE directions!  A flying female who sees a flash will respond with a flash, but she’ll keep going in whatever direction she started in.

Case, J.F.  2004.  Flight studies on photic communication by the Firefly Photinus pyralis.  Integrative Comparative Biology.  44:  250-258.

Now, at this point, some of you may ask, isn’t there an easier way to sex fireflies?  Well of course!  You could catch them, but I’ll save that sort of biology for a different day.  Now you can learn to sex them pretty well just by their dancing.  That’s well worth a watch next time you’re walking around in the evening.  And don’t forget to hum along.


About thomasbiology

I'm an Associate Professor of Biology at Queens University of Charlotte with a background in animal behavior with an emphasis in bird song. I've got two secret goals with this blog (well, since I'm sharing them, they're not so secret): 1. To encourage people to look at the natural world around them- not just as a hiking destination, but to notice all the little things moving around them all the time; and 2. To show some of the science that relates to these little things moving around. There's some really fascinating research out there that so few people get to see.
This entry was posted in communication, ecology, insect, mating, reproduction. Bookmark the permalink.

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