Night-flying biodiversity revealed at TWI sites

This summer, TWI’s biggest hunt for biodiversity didn’t take place in a prairie, a pond, or a seep: We had our eyes firmly on the porch lights, where a dizzying number of moths and nocturnal insects hide in plain sight, waiting to be discovered. Most people think of moths as little more than clothes-eating pests but these winged insects are gorgeous pollinators, often overlooked in favor of their daytime counterparts.

Experts estimate there are 160,000 moth species in the world, many still undescribed (compare this to a mere 20,000 species of butterfly). The moths that scientists have described inhabit a shocking number of niches: There are moths that pretend to be bumblebees, hummingbirds, bird droppings, and dead leaves; moths with wingspans smaller than a quarter-inch and larger than a foot; moths that are parasites, moths that eat exclusively animal fats, and moths that favor a single plant species as a food source. Even in the humble Midwest patient viewers can see iconic species in their own backyards, like the ethereal luna moth, the fuzzy bumblebee-esque snowberry clearwing, and the gargoyle-like small-eyed sphinx. So when TWI embarked on a mission to bring moths to the people through interactive experiences at two project sites in Illinois, the results were stunning.

In just a few months of mothing this summer, TWI’s Trevor Edmonson has come across some of Illinois “moth-ers” most cherished finds, like the chickweed geometer moth. Photo by Trevor Edmonson/TWI.

In just a few months of mothing this summer, TWI’s Trevor Edmonson has come across some of Illinois “moth-ers” most cherished finds, like the chickweed geometer moth. Photo by Trevor Edmonson/TWI.

Another treasured find for Illinois moth enthusiasts, the gorgeous blackberry looper moth. Photo by Trevor Edmonson/TWI.

Another treasured find for Illinois moth enthusiasts, the gorgeous blackberry looper moth. Photo by Trevor Edmonson/TWI.

TWI kicked off a season of moth-related events in July during National Moth Week, in collaboration with the Chicago Park District and Audubon Great Lakes at Indian Ridge Marsh on Chicago’s Far South Side. It was a unique nighttime activity at the urban site, which TWI is helping to restore.

A National Moth Week celebration at Chicago’s Indian Ridge Marsh attracted more than 30 participants—and 76 moth species. Photo by Vera Leopold/TWI.

A National Moth Week celebration at Chicago’s Indian Ridge Marsh attracted more than 30 participants—and 76 moth species. Photo by Vera Leopold/TWI.

TWI Project Manager Trevor Edmonson served as master of ceremonies, bringing along his simple mothing setup—a bedsheet, a lamp with a special mercury vapor lightbulb, and a gas-powered generator. A few old camera stands held the sheet in the front of the lamp, creating a moonlike beacon irresistible to light-seeking moths.

More than 30 participants of all ages gathered around Trevor’s sheet to watch the nocturnal insects fly by. By the end of the evening, the ragtag team of volunteers had photographed and identified 76 species. “This was one of our all-time most successful volunteer events at Indian Ridge Marsh, both in terms of community engagement and scientific impact,” says Vera Leopold, TWI’s grants manager who knows the site well as a regular bird monitor there.

Here at TWI, the buzz about moths started in the wake of our 2018 BioBlitz at the Dixon Waterfowl Refuge in north-central Illinois, when experts Frank Hitchell and Drew Carhart helped us identify more than 140 species in just two hours. Watching Frank at work inspired Trevor Edmonson, who spent the months after the BioBlitz becoming TWI’s in-house authority on all things nocturnal and winged. The sheer diversity of Illinois’ moth population was enough to stir Trevor’s interest: “For every one butterfly in Illinois, I learned there are at least 20 moth species,” he says. Like the bees and butterflies that call the Refuge home, moths are prodigious pollinators, and some ultra-rare plants like the eastern prairie fringed orchid rely on moths alone to guarantee a next generation.

Equipped with reflectors, a headlamp, and a special lens, Trevor has all he needs to photograph moths—including the essential prone position. Photo by Phoebe Thatcher/TWI.

Equipped with reflectors, a headlamp, and a special lens, Trevor has all he needs to photograph moths—including the essential prone position. Photo by Phoebe Thatcher/TWI.

So why are so many citizen scientists underinformed about these night-flying wonders? “Moths do so much, but they are most active when we’re asleep,” Trevor explains. “For us, they’re out of sight, out of mind, yet they play a huge role in every ecosystem.”

Peoria’s Frank Hitchell was once a moth neophyte too. Butterfly-catching adventures with his young daughter led him to get more interested in the dark side of the order Lepidoptera and, 25 years on, he is president of the Peoria Academy of Science’s entomology division. For Frank, the appeal of moths is in the rich history of the field and the constant thrilling changes in diversity from season to season, and even week to week. One of Frank’s most memorable encounters with mothing history took place right outside his hometown of Peoria when he ran across an unassuming but nonetheless special critter: Peoria approximella, a rarely seen moth first described by a Peoria-based entomologist in 1866. “I mean, somebody was collecting moths with a wingspan of half an inch in central Illinois in 1866,” enthuses Frank. “For so long, people have spent their time studying insects.”

The Peoria Academy of Science’s Frank Hitchell examines nocturnal insects by lamplight at the Dixon Waterfowl Refuge. Photo by Lindsay Appel.

The Peoria Academy of Science’s Frank Hitchell examines nocturnal insects by lamplight at the Dixon Waterfowl Refuge. Photo by Lindsay Appel.

The quest to describe every moth is far from over: Regular hobbyists can discover whole new species with a simple backyard setup. Through just his Peoria outings, Frank estimates he has captured about 12 species of moth (and one genus) that are so far undescribed by science. “You can go out to the same spot for years and still discover new diversity,” he says.

At the end of this season, TWI held a Moonlit Mini-Blitz on September 7 at the Dixon Waterfowl Refuge to survey amphibians, owls, and other creatures from dusk to dark. Citizen scientists and TWI staff gathered around Trevor’s bedsheet once more to catch a glimpse of just a fraction of the insect diversity at the Refuge. The group ran the gamut from four-year-old Emmett, there with his dad, to many longtime TWI volunteers and even Frank Hitchell himself. As cricket frogs chirped and cicadas hummed, folks snapped away with fancy digital cameras and iPhones alike, gathering data that will inform conservation efforts at the Refuge. Maybe Trevor will follow in Frank’s footsteps and one day discover a new moth species there: Dixon approximella, anyone?

Learn about the moths of the Dixon Waterfowl Refuge here.