Fireflyers International Network (FIN) has just announced the first-ever World Firefly Day, an annual event to raise awareness about these tiny insects and spark interest in their conservation. Their goal is to get firefly fans all over the globe to celebrate by participating in local firefly-watching festivals, education programs, art exhibits, night walks, and more. For more info, visit the FIN website here.
“Tis strange – but true; for truth is always strange. Stranger than fiction.”
– Lord Byron, Don Juan (1823)
The previous episode left our Pyractomena larva hanging – literally – doing some aerial pupation, very unusual behavior for a firefly! Forsaking the amphibious wanderings of its snail-eating childhood, the pupa now hangs quietly. But inside, a maelstrom of cellular reorganization and growth is transforming its larval body. In just a few weeks, it will emerge as an adult firefly. At this next stage, our Pyractomena will have only one thing on its mind: sex. And yup – you guessed it: Pyractomena fireflies have strange sexual habits, too!
Most male lightningbugs fly & flash to win females. But after racing to emerge early, Pyractomena borealis males forcibly mate with their child brides! Continue reading
We’ve already heard (previous post) about the weird hunting habits of Pyractomena larvae – they’re amphibious. So let’s continue our Pyractomena tour, moving along to consider another strange behavior: they pupate en plein air!
Once they’re ready to metamorphose into adult fireflies, the larvae of most North American lightningbugs seek safety underground. Immobile, they huddle for weeks in soil chambers, finally emerging to light up our skies as adult fireflies. But no cold dark cellars for Pyractomena fireflies! Instead, these strange fireflies climb up onto vegetation to undertake a feat known as aerial pupation.
If you’ve been paying some attention, you probably already know that here in North America, we’ve got several different kinds of lightningbug fireflies. Those in the genera Photinus and Photuris are common and relatively well-studied. But the Pyractomena lightningbugs – also pretty common – are a black box. We know so little about them! And more’s the pity because Pyractomena have a pretty bizarre lifestyle, making them quite a bit different from our other fireflies.
So here’s the first taste of Pyractomena strangeness: these amphibious larvae are snail-eaters! Continue reading
Autumn happens to be quite an exciting time for fireflies. I get it – you probably can’t imagine fireflies beyond summer. And that is when adult get all reproductive and stuff. But there’s cryptic chapter in the firefly’s life story, and it’s starting right now.
Once mated, the female firefly will produce 30-100 eggs, laying them one-by-one in some moist dirt or moss. After a few weeks, these eggs hatch out into tiny larvae that immediately burrow down underground. Though adult fireflies only live a few weeks, their progeny will spend up to two years hanging out underground.
Baby fireflies happen to be voracious predators. They’re constantly on the hunt for earthworms, snails, and any other soft-bodied prey. They attack creatures that are much bigger than themselves. How do they manage this? First, they use their sharp, sickle-shaped jaws to inject the prey with paralyzing neurotoxins. Next, they secrete digestive enzymes to liquify their prey, then they slurp it up. Earthworm smoothie, anyone?
When they’re disturbed, larval fireflies glow from two tiny lanterns located at the tip of their abdomen. All firefly larvae can light up, across 2000+ species, even when the corresponding adults cannot. So we think fireflies’ light-producing talent first evolved because it gave these juveniles some advantage.
But … what’s the point of these juveniles being so conspicuous?
We know that fireflies contain nasty-tasting chemicals that help them avoid getting eaten (see earlier post). Lots of poisonous creatures use bright coloration to warn off potential predators. Yet firefly larvae are mainly active at night or underground, where having bright colors would be futile. But a flash in the darkness would certainly do the trick – like a neon sign, it blazes out “I’m toxic – stay away!”
So get ready to watch for firefly larvae crawling along roadsides and wooded paths, glowing dimly. Often overlooked, these juveniles should rightly be celebrated as the original inventors of fireflies’ magical lights.
Over the past year, I’ve learned a lot about Twitter hashtags. For instance:
#firefly will usher you directly into the cult kingdom of the TV series Firefly, a sci-fi classic billed by its creator as “nine people looking into the blackness of space and seeing nine different things.” The story centers on the crew of Serenity, a Firefly-class starship (when it took off, the ship’s tail section lit up). Premiered on Fox in 2002, the show featured a smart script, terrific ensemble acting, heartthrob Nathan Fillion, and a great theme song. In spite of all this, and to the eternal dismay of its many loyal fans, the show went extinct after just a single season. But on Twitter, it lives on.
Meanwhile, #fireflies yields an endless stream of tweets and Youtube remixes posted by fans of the song “Fireflies” by Owl City. Topping the US and Canadian charts in 2009, this song ties together insomnia, fireflies and summer. Most frequently tweeted are these lyrics: Continue reading