Nature's Light Show!
Posted on June 11, 2021
Our favorite light show of the summer isn’t necessarily 4th of July fireworks, or stars in a clear night sky (though we do love those too!). It’s the beautiful twinkle of fireflies decorating an evening landscape. They are such a common sight that we rarely pause to think about what a fascinating phenomenon we are witnessing. I mean, they light up! That’s kind of amazing, right?
So what creates that lovely glow? Well, they have special light organs located under their abdomens. When the bugs take in oxygen, the cells in these organs combine it with a substance called luciferin, which produces a "cold light" with no infrared or ultraviolet frequencies. And why do they do this? To attract mates, why else?
These insects (actually members of the beetle family) only live two to four weeks once they've reached their adult stage. That means they only have two to four weeks to mate. And when you are a little black bug looking for OTHER little black bugs flying around in the dark? It's really helpful to have a flashing beacon on your rear end. Generally, fireflies flash their lights intermittently, in patterns unique to each species. Get a lot of them looking for love in one area, and you've got a pretty cool light show.
Fireflies also flash as a defense mechanism. We don’t know this from experience, but we’ve been told that fireflies taste pretty bad. The lights are like a signal lamp flashing morse code to predators: "I’m not food! Move along!"
There is one exception to this: the female fireflies of a particular genus, Photuris. These "femme fatales", as they are known to entomologists for reasons that will soon become apparent, are able to expertly mimic the different flashing patterns of other genuses, tricking a hapless male into thinking he has found a mate. Instead, the photuris firefly EATS HIM. See, photuris don't naturally have the yucky-tasting compounds that make other fireflies distasteful to predators... but they can absorb them by eating the fireflies that do have them. Moreover, they can then pass them on to their own eggs to defend the next generation. And you thought the human dating scene was stressful!
So the next time you are watching a firefly light display, keep in mind the drama that is really happening before your very eyes!
