Fireflies: A dimming glow

For many, fireflies are harbingers of summer, their tiny twinkles of light softly illuminating warm evenings. Their magic goes beyond simple wonder. Scientists have put the beetles’ alchemy—they’re not actually flies—to work in the lab, too. There are fireflies on all continents [except Antarctica]( but not everyone has experienced this phosphorescent phenomenon, and if recent trends are any indication, the firefly population is in danger of fading away. (Though this year [has been a good one]( at least in the US, for fireflies.) Let’s shed some light on these enchanting insects. 🐦 [Tweet this!]( 🌐 [View this email on the web]( Sponsored by [Quartz Obsession] Fireflies August 13, 2019 For many, fireflies are harbingers of summer, their tiny twinkles of light softly illuminating warm evenings. Their magic goes beyond simple wonder. Scientists have put the beetles’ alchemy—they’re not actually flies—to work in the lab, too. There are fireflies on all continents [except Antarctica]( but not everyone has experienced this phosphorescent phenomenon, and if recent trends are any indication, the firefly population is in danger of fading away. (Though this year [has been a good one]( at least in the US, for fireflies.) Let’s shed some light on these enchanting insects. 🐦 [Tweet this!]( 🌐 [View this email on the web]( Giphy By the digits [2,000:]( Species of fireflies—but only some of them glow [2:]( Years the average firefly spends in its larval stage [2:]( Months the average firefly spends in its adult stage [1:]( Billboard Top 100 ranking of Owl City’s “Fireflies” in 2009 [$338:]( Price of a firefly luciferase kit used to detect bacterial contamination [~100%:]( Share of energy from the firefly’s chemical reaction released as light [14.1 microwatts:]( Power a firefly flash consumes [35,000:]( Approximate number of fireflies it would take to equal a 100-watt bulb Giphy Explain it like I’m 5! How and why do fireflies light up? --------------------------------------------------------------- In order to produce that mate-attracting, come-hither glow, fireflies [create]( an internal chemical reaction that combines oxygen—specifically [superoxide anion]( which contains an extra electron—with calcium, adenosine triphosphate (ATP), and the chemical luciferin (from the Latin lucifer, or “light-bearer”). When all of these elements come together in the presence of a bioluminescent enzyme called luciferase, “cold light” is produced inside of the firefly’s light organ. The firefly’s lantern also has [cuticles that optimize the light]( like the lens on a lighthouse or headlight, which scientists are studying to [create better bulbs](. The flashes perform several functions. Like singles at a bar, they use flashing to flirt until a compatible couple from the same species hits it off (scientists are still [figuring out their different languages](. They’re warnings to predators that the [larvae use to protect themselves](. And then there’s the genus Photuris, the [“firefly femmes fatales”]( (pdf). Females of this species imitate the flash patterns of the Photinus to lure and eat them. Sponsored by Slate New podcast from Slate: How To! --------------------------------------------------------------- What if Dear Abby was an investigative reporter? Each week, Pulitzer Prize-winning journalist and The Power of Habit author Charles Duhigg takes on listeners' toughest problems and, with the help of experts, finds the answers to the questions we've always wanted to ask but felt we couldn't. Subscribe to How To! in Apple Podcasts or wherever you listen.[Learn more at Slate.com]( Quotable “Here come real stars to fill the upper skies, And here on earth come emulating flies” ―From [“Fireflies in the Garden”]( by Robert Frost Reuters/Edgard Garrido This one weird trick! How mankind harnesses fireflies --------------------------------------------------------------- Because luciferase creates light when it reacts in combination with ATP, [“the energy currency of life,”]( it’s handy for identifying things like [bacterial contamination]( and [cancer cells]( which is why you can buy [firefly luciferase assays](. Scientists can also attach the luciferase gene to other genes, insert the combo into DNA, and then get a notification [when the gene turns on](. Jargon watch Is there a difference between fireflies and lightning bugs? --------------------------------------------------------------- Nope, just linguistic geography at work. [According to a survey]( conducted by Cambridge linguistics professor Bert Vaux, 39.8% of US respondents use both terms, 30.4% use “firefly” and 29.1% prefer “lightning bug.” Then there’s the 0.02% who call them “peenie wallies,” which is another story entirely. Other terms [include]( lamp bugs, will-o-the-wisps, candleflies, and firebobs. Glow worm is more commonly used outside the US, and more specifically refers to a species in which the adult females are wingless. Here’s [a map of the language divide](. Why the split? [One theory]( is that people in areas of the US where lightning strikes are common, largely the Midwest and the South, call them lightning bugs. Those who reside in parts of the country where wildfires are common, mostly the west, call them fireflies. Have a friend who would enjoy our Obsession with Fireflies? [ [Forward link to a friend](mailto:?subject=Thought you'd enjoy.&body=Read this Quartz Obsession email – to the email – Million-dollar question Are fireflies disappearing? --------------------------------------------------------------- If you grew up with fireflies illuminating summer evenings you may have noticed that the twinkles aren’t as dense as they once were. Turns out it’s not just nostalgia—the population is in decline across the globe, as scientists first [started observing]( about a decade ago. Researchers [believe that light pollution]( may be responsible for the slow demise of the bioluminescent bugs. When their flashing patterns have to compete with other light sources, fireflies aren’t able to identify mates as easily. The open fields and wide expanses of forest that lightning bugs once called home are disappearing in favor of urban development. But there are [things you can do]( to make your property more hospitable to these charming critters, including adding water features to your yard, and turning off exterior lights at night. Reuters/Shailesh Andrade Pop quiz What was the name of the animated glowing beetle in a 1980s-90s PSA about children playing safely near power lines? Louie the Lightning BugGus the Glow WormElectrifying EddieFred the Firefly Correct. Louie the Lightning Bug was voiced by Jack Sheldon, a jazz musician and singer who also provided the voice of Bill in the Schoolhouse Rock classic, “I’m Just a Bill.” Incorrect. If your inbox doesn’t support this quiz, find the solution at bottom of email. Fun fact! There are winter fireflies, but they don’t glow. Members of this North American species [hide]( in tree bark over the winter, find each other using pheromones in April and May, then lay eggs and leave long before the summer fireflies show up. And in the United States, there’s a “continental divide” of fireflies—west of Kansas, females glow very dimly and only on the ground, [so humans barely notice]( them. Road trip In sync --------------------------------------------------------------- There are several locations where, once a year, all of the fireflies in the area flash synchronously—all at once or in waves across hillsides—creating a jaw-dropping, otherworldly display. [According to the National Park Service]( “No one is sure why the fireflies flash synchronously. Competition between males may be one reason: they all want to be the first to flash. Or perhaps if the males all flash together they have a better chance of being noticed, and the females can make better comparisons.” [Nanacamilpa, Mexico]( In June and July, tourists flock to this lightning bug hotspot in the state of Tlaxcala, located east of Mexico City. [The Great Smoky Mountains:]( Perhaps the most famous synchronized firefly location, the Great Smoky Mountains are home to mating fireflies for two weeks every year. While it’s hard to predict exactly when mating season might happen—temperature, weather, moon phases, and soil moisture are all thought to play a part—it usually occurs sometime from mid-May to mid-June. It’s become so popular that tourists now have to enter a lottery system. [Congaree National Park, South Carolina:]( Timing here is similar to the Great Smoky Mountains—May to June—but it’s much less crowded, so no lottery is required. According to the Smithsonian, this spot is even better than the Smokies, in part because the light of the low-flying fireflies is reflected in the swamp waters, creating double the effect. [Allegheny National Forest (ANF), Pennsylvania:]( A relatively new entry into the synchronous firefly game, discovered in 2011. There’s now an [annual firefly festival]( held in late June. [Southeast Asian mangrove forests:]( Unlike the synchronous fireflies in North America, fireflies in the Philippines and other areas in Southeast Asia mate year-round, which can create an overlap between adult fireflies and newly winged fireflies. That means double the number of amorous insects, so trees along riverbanks are absolutely aglow in the evenings from January to December. Watch this! If you can’t make it to Southeast Asia or haven’t yet won the Great Smoky Mountains lottery, this video of firefly synchronization is the next best thing. And when you’re done being impressed with that, check out a similar phenomenon in New Zealand: [Glow worm caves](. Giphy Poll What do you call these glowing beetles? [Click here to vote]( FirefliesLightning BugsPeenie Wallies 💬let's talk! In yesterday’s poll about [checklists]( 66% of you said the best way to keep them is “pen and paper, the old-fashioned way.” 🤔 [What did you think of today’s email?](mailto:obsession%2Bfeedback@qz.com?cc=&subject=Thoughts%20about%20fireflies&body=) 💡 [What should we obsess over next?](mailto:obsession%2Bideas@qz.com?cc=&subject=Obsess%20over%20this%20next.&body=) 🎲 [Show me a random Obsession]( Today’s email was written by [Stacy Conradt]( edited by [Whet Moser]( and produced by [Luiz Romero](. The correct answer to the quiz is Louie the Lightning Bug. Enjoying the Quartz Obsession? 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