Last week I had a chance to chat with Nate Butkus, 10-year old host of The Show About Science. We decided to start a FireBeetle* movement, and I geeked out about the gory side.
Meanwhile, enjoy these visuals from KQED’s Deep Look!
*Unfortunately, the name “fire beetle” has already been snagged by an Australian beetle (Merimna atrata) whose larvae develop in freshly burnt wood.
Watching a whole forestful of fireflies flashing together in unison is a truly mesmerizing experience. As I described in an earlier post, males of only a few firefly species are capable of this remarkable feat. Although we still don’t know why this behavior occurs, some researchers at the University of Colorado – Boulder recently developed cool tools to shed new light on how fireflies accomplish this collective behavior.
Using Go-Pro cameras to film Photinus carolinus in the Great Smoky Mountains National Park, Raphael Sarfati and Orit Peleg were later able to reconstruct the 3D flight paths of individual male fireflies. You can read about their study in this month’s Smithsonian Magazine, or check out their original paper in the Journal of the Royal Society Interface.
Their findings provide clues into how insects with relatively small brains can perform such seemingly complex synchronous behaviors. By demonstrating how fireflies kick off their synchrony, this research will inspire new advances in swarm robotics. In the future, their tracking methods could also be adapted for community science projects like Firefly Watch in the U.S. to help scientists monitor long-term trends in firefly populations.
Autumn happens to be quite an exciting time for fireflies. But, yeah I get it – you probably can’t imagine fireflies beyond summer. After all, 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.
photo by Melvyn Yeo (Flickr)
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.
Illustration by pageofbats (Flickr)
Silent Sparks 