Kids these days have some decent summer options. There are camps for everything. Internships abound. And you can always still flip burgers or cut grass.

But the latest generation has missed out in at least one way. No longer are children paid to run around at dusk, armed with a chemical company’s branded net, tasked with catching fireflies for a penny per head.

From 1960 through the mid 1990s, the Missouri-based Sigma Firefly Scientists Club brought in tens of millions of fireflies—caught by kids and overzealous adults across 25 states, shipped in special company containers, and ground up into dust for various bioindustrial purposes. Club members fought for prizes, formed cutthroat business alliances, and wore glow-in-the-dark buttons. It was, in many ways, the ultimate American summer job.

Suspended in the sky on a twilit evening, a firefly’s yellow glow looks a lot like magic. At a cellular level, though, it’s actually a straightforward chemical response. Each bug’s lantern is brimming with an enzyme called luciferase, which, under the right conditions, emits a bioluminescent gleam. In order to light up, the enzyme needs ATP—a kind of cellular energy packet found in all living things. If a firefly’s lantern were an oil lamp, ATP would be the fuel, and luciferase the match that lights it.

A solo firefly, showing off his valuable enzymes.
A solo firefly, showing off his valuable enzymes. terry priest/CC BY-SA 2.0

Scientists discovered this mechanism in the late 1940s, and soon after, biochemists began figuring out how to put it to use. An up-and-coming St. Louis chemical company called Sigma quickly realized that the enzyme could detect bacteria in supposedly sterile environments, literally lighting up around living things, and developed a suite of chemicals to take advantage of this. “It was basically a life-detecting kit,” explains Sara Lewis, a firefly expert at Tufts University, and the author of Silent Sparks: The Wondrous World of Fireflies. “That was big business for them.” To make it, they needed luciferase—lots and lots of it. And at that point, the only source was firefly butts.Enter the world’s least likely supply chain: Midwestern children. “The only way to get a lot of those fireflies easily was to have a whole bunch of kids catching them,” says Theresa Huether. Huether, now a retired math professor, spent a couple of college summers working in Sigma’s firefly labs, in 1975 and ‘76. If the best way to catch fireflies was with children, she says, the best way to catch children was with cool stuff—T-shirts, nets, and buttons branded with a club-house worthy title, and cold, hard, penny candy money.

Thus was born the Sigma Firefly Scientists Club. In the summer of 1960, ads and articles began popping up in local papers across the Midwest. “CATCH LIGHTNING BUGS!” shouted one classified in the St. Louis Post-Dispatch, nestled among boring ads about appliances and mattresses. “Hey Kids! Join the Sigma Firefly Scientists Club,” read another, in Illinois’s Alton Evening Telegraph. “It’s fun. It’s profitable and an opportunity to make a valuable contribution to science.”

An early ad for the club, from the June 2nd, 1960 St. Louis Post-Dispatch.
An early ad for the club, from the June 2nd, 1960 St. Louis Post-Dispatch.

The article goes on to detail the stakes of the operation (“Sigma is appealing to youngsters throughout the St. Louis area… every single firefly is important to the work”), and the bounty involved (“30 cents in cash for each 100 bugs, or one dollar in ride tickets at Forest Park Highlands, Holiday Hill or Chain of Rocks Fun Park.”) Plus, they write, it’s easy—just put the bugs in a jar with a few holes poked in it, and stick it in the refrigerator until dropoff day.

It’s not hard to imagine how thrilling this proposition would have seemed to the average kid—their unique skills, recognized and rewarded at last! And they’d get to put bugs in the fridge to boot! Before long, the Sigma Firefly Scientists Club hardly had to advertise. Kids wrote into Boy’s Life, tipping off fellow kids about this “interesting way to earn money.” Adults, too, found it wholesome: “Club members have fun and get exercise while earning money for themselves or their projects,” beamed one St. Louis paper.

Sigma kept their youthful suppliers apprised of the fruits of their labor—which also, somehow, covered kid-approved topics. Sure, luciferase was used to study cancer and heart disease, but it was also repurposed as a shark repellant, and to test for bacteria in Coca-Cola. Kits even went to Mars with the Viking expedition, where they were used to hunt for extraterrestrial life. “Scientists mixed the chemicals with some Martian dust,” summed up UPI, doubtlessly inspiring hours of summer daydreams.

A model of a luciferase enzyme.
A model of a luciferase enzyme. ynse/Flickr/CC BY 2.0

Soon the club had thousands of members, scattered over 25 states. Though comprehensive data isn’t available, in its heyday, the club brought in over three million fireflies per year. Such a large operation required slightly more structure. By the mid-1970s, in return for a small deposit, club members received a firefly-hunting kit: an explanatory pamphlet, shipping canisters lined with desiccant, and a net silkscreened with the club’s official insignia—a bow-tied, white-gloved bug. (They also got buttons, whose dapper fireflies boasted glow-in-the-dark tails.)

Thus armed, the children roved around towns at night, snagging their prey. Once they had filled their canisters, they’d ship them off, dead or alive, to Sigma. “There was a little form, and the kids told us how many bugs there were,” says Huether. “We didn’t count them—we trusted them.” They sent back checks made out in the kids’ names, with the club logo stamped on them.

Most club members were hobbyist firefly hunters, too small-time to even bother with equipment. (“There were a lot of kids in St. Louis that sent us bugs, and some of them were in Ziploc bags,” says Huether.) But there were mavens, too.

Under Sigma’s sliding scale system, a bigger haul meant a proportionately higher payout—you started at 50 cents for every hundred flies, but once you reached 20,000, you were up to one cent per bug. Towns and clubs pooled their resources to make this mark. The Allison Firefly Club, in Iowa, brought in a million insects over five years, and used their take to build a community pool.

The true firefly mafia, though, was in Vinton, Iowa, an agricultural town that spawned at least two unlikely dons. “There was this one kid, a 10 or 11-year-old boy,” says Huether. “He rented a whole bunch of firefly nets, and hired a bunch of kids.” Rather than sending their catches straight to Sigma, the kids worked for him at a lower rate. He took care of the logistics, and made a tidy profit: “He got well over the 20,000 mark, so he was making a penny apiece.” Not bad for a preteen.

Fireflies in full force, out in a field.
Fireflies in full force, out in a field. Matt MacGillivray/CC BY 2.0

Vinton was also home to Judy Wood, aka the “Lightningbug Lady.” Wood spent the school year as a teacher’s aide, and leveraged her free summers and massive kid network into a sprawling bug enterprise. Over 400 kids brought their catches to her nightly, from as far as 45 miles away. She also trawled for fireflies herself, driving a pickup truck specially outfitted with a mesh net. Combined, the two strategies brought in staggering numbers. “The average is about 35,000 that I bus to St. Louis every other day,” Wood told the Chicago Tribune in 1987.

Wood did this every summer for over 25 years, and used her fly money to put her kids through college. For basically everyone else, it was a brief exercise in summer capitalism. “It was kind of a win for kids, because they got some money for doing something they thought was fun,” says Huether. “And clearly it was a win for Sigma.” (Huether and her coworkers enjoyed it, too—“it was a really, really fun job,” she says.)

The only constituency that lost out was, well, the fireflies. Lewis, the firefly expert at Tufts, calculates the Sigma Firefly Scientists Club pulled in about 100 million wild-caught fireflies during its tenure, if we use the three million number as an annual average. “The commercial harvesting of fireflies seems like something that should be banned,” she notes.

Firefly population data is slim, and there are certainly larger threats facing the critters—habitat loss, light pollution, pesticide use. But 100 million isn’t nothing. More than that, Lewis says, it’s the principal of the thing: “Here’s something that’s a shared natural resource—it’s a source of wonder for everybody,” she says. “It doesn’t make sense to me that some people should be allowed to go out and harvest vast numbers.”

A jar of whole fireflies from Sigma.
A jar of whole fireflies from Sigma. Sara Lewis

And they don’t anymore—at least not for the Sigma Firefly Scientists Club. For as-yet undisclosed reasons—the changing ecological mood, child wage inflation, the expiration of AMGEN’s patent on synthetic luciferase—Sigma quietly shuttered the club sometime in the late 1990s.

A recent profile of the company, now called Sigma-Aldrich and valued at $17 billion, brought up this ancient history with current employees, some of whom were former members. All laughed: “What kind of company would do that anymore?” the reporter asked. That particular age—of innocence, or ignorance, or both—has passed.

Some remnants, though, have stuck around, with a kind of macabre afterglow. You can still buy a jar of whole fireflies from Sigma, pulled from the vast overstock provided by the club. Or you could head out and watch them flitting around, the bounty now off their heads, lighting up for their own lives.