Around Christmas each year, I start getting reports from astonished fans about what looks like glowing fireflies lighting up nearby trees. Just last week my neighbor in New Hampshire was thrilled to see what he thought was definitely the courtship display of blue ghost fireflies!
If you’ve followed my posts, you know that fireflies across most of the U.S. survive winter hanging out in a juvenile stage. But… these glow-worms stay underground and are typically dormant until temperatures warm up in the spring. You might also know there’s a real Winter Firefly (Ellychnia corrusca) whose adults spend winters hunkered down on tree trunks. But… these are dark fireflies whose non-luminescent adults only begin flying in the spring.
It’s mid-winter, and lightningbug mating season is still months away, so what the heck is going on??!! Wishful thinking? Mass hallucination? Nope – it’s a simple case of mistaken identity.
Outdoor laser projectors have recently become a popular addition to winter holiday decor. These projectors send out dancing points of light – when they shine up into nearby trees, it seems like the treetops are filled with flashing fireflies! Check out the video below:
So next time you start hearing rumors about winter lightningbugs, you won’t get duped – just ask your neighbors! And enjoy the Christmas “fireflies”.
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.
I’m doubly appreciative of fireflies this year, as they’ve given us two fabulous gifts. One, the incredible gift of wonder. The other gift is a tiny molecule, precious and pragmatic.
Luciferase is a light-producing enzyme that was invented by fireflies. Over eons of evolution, it’s been fine-tuned to help fireflies find mates and avoid predators. And now this firefly enzyme has been harnessed by humans to help us fight against the global pandemic of COVID-19.
Surely it seems like magic, but firefly light comes from a carefully orchestrated chemical reaction that happens inside the firefly’s lantern. Luciferase hosts the party, inviting multiple guests (including ATP, oxygen, magnesium, and a much smaller molecule called luciferin), then sparking them to engage in a scintillating conversation that gets them excited enough to give off light.
Ever since its discovery in the late 1940s, firefly luciferase has been harnessed by scientists to improve human health. Early on it got used in food safety testing to detect good food gone bad – that is, food that’s been contaminated by microbes and so is unsafe for human consumption. To test meat, diary and soft drinks, kits made from firefly-derived chemicals would light up to show if a sample was contaminated with even tiny amounts of harmful bacteria. Similar kits were used by the pharmaceutical industry to measure cell viability when they tested anti-tumor drugs. Surprisingly, for over 30 years every smidgeon of luciferase that went into these kits came from wild fireflies harvested by collectors all across the U.S.
Each summer the Sigma Chemical Company recruited a small army of collectors that got paid ~50 cents per 100 fireflies; a $20 bonus awaited anyone who sent in 200,000 fireflies. All told, Sigma extracted luciferase from about 90 million wild-caught fireflies!! (Yes, I know it’s hard to believe. But you can find out more about bounty-hunting fireflies in Silent Sparks Chapter 8: Lights Out for Fireflies? or this story in Atlas Obscura). Quite fortunately for U.S. fireflies and their fans, in the 1990’s scientists finally decoded the DNA sequence that fireflies use to make luciferase. Using harmless bacteria as a bioproduction platform, synthetic luciferase soon became widely available.
Fireflies have enabled many advances in public health and medicine. Once the luciferase gene (this gene’s nickname is luc) was deciphered, the scientific and biomedical uses for firefly luciferase skyrocketed. Widely used as a genetic “reporter”, luc can be spliced together with any other target gene that scientists might want to study. Whenever the target gene gets activated, luc acts like a spy who reports back by emitting light, which can be quickly and easily measured using sensitive cameras.
Right now, firefly luc is helping us to understand and fight public enemy #1, the SARS-CoV-2 virus that’s responsible for the global pandemic of COVID-19.
A first step to conquering this deadly disease is understanding how the SARS-CoV-2 virus enters and replicates inside host cells. Researchers at Texas Medical Center have studied this process using pseudotyped viral particles. They grafted the S-protein from SARS-CoV-2 onto an innocuous virus, then added firefly luc as genetic reporter. When these pseudo-typed viruses attacked a cultured host cell, luc announced the attack loud and clear: the replicating virus particles emitted light, which could be measured very accurately to determine virus replication rates.
In a completely different application, a research team in Japan has combined luciferase with a fluorescent protein to invent a very sensitive antibody test. Their test quickly detects multiple antibodies using just a tiny drop of blood, and the results are read using a smartphone app. As scientists race to figure out how to treat and prevent COVID-19, it seems that fireflies may help us win this fight.
These beloved insects have given us so much – the gift of wonder + the gift of light. We owe them a huge debt of gratitude, so the least we can do is preserve them for future generations to enjoy. And who knows what other chemical riches lie waiting to be discovered within the firefly pharmacopiea?
“The broken world waits in darkness for the light that is you”
In 2020 the global pandemic of COVID-19 truly broke apart our world. This summer, when our days are filled with anxiety and despair, how can we find the courage to continue doing the work needed to repair the world?
Some people think fireflies are just tiny insects, but for me they’re so much more! They are luminous beings whose natural magic inspires optimism and hope even during the darkest times. That’s why we’ve chosen Hope Rising as the theme for World Firefly Day 2020.
While we celebrate on July 4-5 (also Independence Day in the U.S.), scientists around the world are working hard to develop a vaccine that will protect humanity from this deadly disease. At the same time, we’re working hard to preserve these hope-filled sparks for future generations to enjoy. Even though fireflies have simple needs – water, food, and shelter – they face major threats from loss of suitable habitat, light pollution, and widespread pesticide use.
Here are some simple things we all can do to help fireflies survive:
Protect their homes: help preserve the places where fireflies thrive.
Turn off the lights: too much light at night disrupts firefly courtship.
Don’t use pesticides in your lawn or garden: neonics and other insecticides harm juvenile fireflies.
And please help us spread the word by sharing more tips for creating more firefly-friendly places with others in your Home Owner’s Association, garden club, neighborhood, or town.
Because who’d want to live in a world without fireflies?
Since 2017, the Fireflyers International Network has been sponsoring World Firefly Day, held during the first weekend in July. In previous years, people all over the world have come together to joyfully celebrate the magic and the science of fireflies with festivals, talks, and other events taking place in Malaysia, Thailand, China, Belgium, Mexico, USA, and many other countries. More than mere insects, these luminous beings help keep us connected to Earth’s natural magic.
During 2020, the global coronavirus pandemic has profoundly disrupted our lives. It has taken away loved ones and livelihoods, spread grief and despair, and divided us from family and friends. We wake each day heavy-hearted, weighed down by the gravity of the news. To confront these dark times, we have chosen to center World Firefly Day 2020 around Hope Rising!
Icons of summer, harbingers of monsoons, for centuries these beloved insects have sparked joy and inspired wonder for people all over the world. During these dark times, fireflies also remind us of the great resilience of the natural world, so full of life! So we celebrate them this year as tiny beacons of hope, sparkling lights carrying a promise that humanity will emerge into a brighter future.
Because festivals and gatherings have been cancelled, World Firefly Day 2020 will be celebrated virtually with videos, music, and presentations posted on FIN’s Youtube channel and on FIN Facebook. If you can’t enjoy real fireflies this year, please join our virtual celebration by sharing your firefly stories, poems, photos and artwork with your fellow firefly enthusiasts on FIN Facebook!
When everything has been turned topsy-turvy, tuning in to nature’s rhythms can provide comfort and consolation. With summer camps cancelled and vacations vanished, many of us are preparing to spend this summer at home. So how about a staycation with fireflies? Step out into the night and look for fireflies in your backyard or local park. Camp out with the kids & catch some fireflies in a jar (remember to keep them happy with an apple slice or some damp paper towel). Grab a penlight and practice some lightningbug linguistics. Join the citizen scientists over at Firefly Watch and help us keep track of long-term trends in your local firefly populations.
Stay safe, be well, find joy – we will recover, we will rise up & shine brightly once again!
So excited to announce that we just published the first-ever comprehensive review about the threats facing fireflies around the globe!
In this article we also describe several things we all can do to give fireflies a brighter future. You can read our article here (we’re tremendously grateful to BioScience for making this Editor’s Choice & freely available).
I’m also delighted to announce my upcoming 1-year sabbatic leave from teaching at Tufts University, starting in May 2020. I’m looking forward to spending more time working on several firefly conservation initiatives, including serving as co-chair for the IUCN Firefly Specialist Group and working with my colleagues at Fireflyers International.
In the meantime, you might enjoy this great article in The Guardian summarizing the work that we & many others have been doing to keep the firefly magic alive!
Earth’s biodiversity is rapidly disappearing, with an estimated 1 million animal and plant species currently threatened with extinction. Fighting to save species, habitats, and ecosystems from extinction using an evidence-based approach has been the central mission of the International Union for the Conservation of Nature (IUCN) since 1948. Last week we had a unique opportunity to raise awareness about firefly diversity, to start identifying those firefly species most threatened by extinction, and to take positive action to conserve them.
We landed in Abu Dhabi, where our IUCN Firefly Specialist Group had been invited to meet with leaders of other Specialist Groups. For decades, these groups have been focused not only on charismatic wildlife like lions and leopards, pangolins and polar bears, but also on frogs and fungi, seahorses and seagrass. We were so honored to bring fireflies to this conservation forum for the first time! Over four intense and productive days, we shared ideas, challenges and opportunities with 300 volunteer scientists and species conservation experts all passionately dedicated to conserving Earth’s biodiversity. It was educational, exhilarating, and exhausting – and also very hot (we were encouraged not to go outside because it felt like 128ºF one day)!
“We call on all people, especially young people, to make a stand and stand up for all species.”
The Abu Dhabi Call for Global Species Conservation Action, 2019
Which fireflies are fading out & how can we save them?
Going forward, our Firefly Specialist Group will apply evidence-based science to identify which fireflies are most at-risk by assembling what we already know about each species’ biology, ecology, changes in population size, and geographic range. Then we can protect species that fall into IUCN Red List threatened categories by developing and implementing conservation action plans.
Next we traveled to Malaysia, where I was once again fortunate to see some exciting firefly education and conservation projects in action. I’m excited to share a few with you!
Conserving urban green space: Bukit Kiara, a former rubber plantation turned urban park that lies smack dab in the middle of Kuala Lumpur. Along freshwater springs, biking, and walking paths the regenerating forest supports a healthy population of giant glow-worms (Lamprigera species). On our walk we found not only two gigantic wingless females (left-hand photo below), but also nearly a dozen glowing larvae moving rapidly across the forest floor as they searched for prey (middle photo). Females’ inability to fly severely limits the dispersal distance of these (and other) glow-worms, thus making them especially vulnerable to habitat fragmentation and loss due to encroaching urban development. By serving as a flagship species, these fireflies could help the advocacy group Friends of Bukit Kiara and other stakeholders convince the government to conserve this urban green oasis.
“The fireflies, twinkling among leaves, make the stars wonder.”
Rabindranath Tagore (1861-1941)
Well-managed firefly tourism: The Malaysian Nature Society empowers local communities by developing and sharing best practices for sustainable firefly tourism through their Firefly Kommunti, a network of firefly tour operators, nature guides and conservationists. This grass-roots initiative helps safeguard firefly populations while providing stable economic benefits for local communities. We visited Kuala Selangor Firefly Park in Kampung Kuantan, where standing oarsman take tourists along the mangrove river in traditional wooden sampans to see display trees sparkling with synchronous Pteroptyx tener fireflies. To restore firefly habitat in areas where riverside vegetation has been cleared, river protectors in the Inspirasi Kawa youth group have replanted saplings of berembang trees (Sonneratia caseolaris), favored by these synchronous fireflies for their spectacular courtship displays.
All the collaborative projects I witnessed – bringing together local NGOs, community members, industry, and conservationists – gave me real hope that we can work together to keep firefly magic alive!
While visiting Thailand and peninsular Malaysia this month, I got to see many exciting firefly education and conservation initiatives. Here’s a glimpse of some conservation action happening right now in Thailand:
Winding down to the sea, the Chao Phraya River curls around the unspoiled island of Bang Kachao, an area known as the green lung of Bangkok. Although mere minutes from downtown, Bang Kachao is home to a surprisingly robust population of the synchronous firefly Pteroptyxmalaccae, whose males take up perches in particular display trees and all flash together in unison to attract females. My colleague Dr. Anchana Thancharoen has established a firefly education center that trains local volunteers to survey firefly populations along a raised bike path through the mangrove forest. Unlike in many other places, these particular fireflies seem unperturbed by the bright lights that illuminate the path – even some trees completely bathed in artificial light have fireflies. Perhaps this population has somehow managed to adapt to such high ambient light. Yet I wonder – without real darkness giving visual contrast to their flashes, can these males still manage to attract females?
Situated within the Phrom Yothi Military Camp in Thailand’s Prachinburi Province, Firefly Land hosts the terrestrial firefly Asymmetricata circumdata. Many tourists come to see their impressive mating displays on weekends. The government is working to protect the fireflies while still allowing people to enjoy the show. They recently installed a fence that prevents visitors from tromping through the fireflies’ habitat, and constructed a raised walkway leading to a covered viewing platform. They even turn off the street lights during the nightly courtship period!
Hey, surprise! Some adult fireflies never.even.light.up 😳.
Yeah, I know it sounds weird. Yet based on shared ancestry (including their bioluminescent larvae), these so-called “dark” fireflies are authentic card-carrying members of the family Lampyridae. Common from coast to coast, each spring they quickly dominate the iNaturalist observations that show up in our Fireflies of the USA and Canada project.
One of my personal favorite creatures happens to be the winter firefly, Ellychnia (ee-lick-ne-ah) corrusca, a species complex that’s widespread across eastern North America from Florida to Ontario. (In all, there are 12+ species in the genus Ellychnia, including several species found just on the west coast – reference below).
Easy to recognize, our eastern Ellychnia corrusca adults sport oval-shaped bodies, entirely dark wing covers (no pale margins), and a distinctive color pattern on their pronotum: a big central black spot is edged with red and enclosed within two pale parentheses.
Winter fireflies earn their common name from the fact that their adults can survive sub-freezing temperatures. Each fall in New England they gather on particular trees – they seem to frequent the same trees year after year – where they wedge themselves into grooves and hunker down to spend the winter. And they are decidedly hardy – in Massachusetts, Jen Rooney and I did a mark-recapture study and found 90% overwintering survival!
In early spring, just when the maple trees begin flowering, winter fireflies start crawling up tree trunks. As temperatures rise, they begin flying through forested habitats in search of mates. Pairs mate in tail-to-tail position, then the female flies off to lay her eggs.
Like all fireflies, Ellychnia larvae are carnivorous. Rarely seen, they live and hunt within decaying wood. Hatching out in early summer, these larvae will spend the next 16 months eating and growing. Not until late summer of their second year will they transform into adults, which gather again on trees to overwinter.
WIthout any lanterns, distinguishing between an Ellychnia female and a male requires a pretty close look at the underside of their abdomen. In females (below right), the last segment is triangular with small notch ; in males (below left), this segment is rounded and unnotched.
Personally, I don’t even care that they don’t light up – I love greeting these dark fireflies each spring! After a long winter, they bring a welcome promise of warm summer nights & lights ahead. So keep your eyes peeled and enjoy these unusual fireflies!