As dusk falls over the Spanish Fork Riverbottoms on a cool June evening, Diane Garcia’s fields begin to twinkle, mirroring the sky above as the stars begin to show against the darkening sky.

The perpetrators of this magical effect are fireflies, whose blinking bioluminescence is part of their mating rituals from late May to early July.

Though the fireflies have been around about as long as Garcia’s family (her great-great-grandfather, Samuel Thompson, settled the farm in 1852), it’s likely many people in the area didn’t know of the fireflies’ existence until last year, when Garcia began leading tours through her fields.

Garcia takes groups of between 40 and 50 people out every night in June, where she shares a history of her farm, and instructs the excited kids in the best techniques for catching the fireflies without hurting them.

“This is a catch-and-release program,” she tells them before heading across the road from her historic home to the fields where the fireflies can be seen. “If you take them home, they’ll just die.”

She further explains that the female fireflies hang out on blades of grass as the males flutter by and “blink” at them.

“If the females like what they see, they blink back,” Garcia said.

Garcia isn’t making any money off the hours she spends leading tours. For her, making sure others get to experience the magic of the floating lights is part of educating people about the fireflies and dangers to the fireflies’ habitat.

Though she plans to continue leading tours until the fireflies cease activity for the year, those who haven’t already scheduled a tour through the Facebook page are probably too late. The tours are already scheduled through the end of firefly season, and the waitlist is a long one.

On one of her tours, Garcia said, two teenage girls had just come back from playing at Carnegie Hall, but approached her to say that their experience seeing fireflies was “much better.”

“And to hear teenagers say that, it’s huge,” Garcia said “To see them just identify that they’re relaxed and at peace when they see things like this in nature, I think it’s awesome.”

In rapidly-growing Spanish Fork, Garcia worries that development creeping closer to her fields could affect the fireflies with light pollution.

“I’m really worried that we won’t have fireflies here much longer,” Garcia said. “I thought that would be really sad if nobody got to enjoy them before they were gone.”

Fireflies aren’t an endangered species in Utah, said Christy Bills, the insect collection manager at the Natural History Museum of Utah, and can be found from Bear Lake to Moab. They prefer, wet, marshy habitats.

Anecdotal reports of fireflies in Utah have existed since the 1950s, Bills said, but they haven’t been tracked or studied much until fairly recently.

The Natural History Museum, in conjunction with researchers at Brigham Young University, began the Firefly Citizen Science Project back in 2013 as a way to track populations throughout the state by encouraging those who see fireflies to report them via the project website at nhmu.utah.edu.

So far, the map includes sightings all over Utah, though more heavily concentrated in the northern portion of the state. Utah County sightings include multiple locations near Spanish Fork, Benjamin, Genola and Spring Lake, with others scattered near Provo, American Fork and Highland.

“There’s a ton in Utah County,” Bills said. “I’m surprised more people don’t know about them.”

But, it isn’t too surprising more people don’t see them, Bills said. After all, they are only adults from late May to early July, and spend the rest of their lives down in the mud. They also tend to inhabit wet, swampy places typically avoided by humans.

Once a sighting is reported, Bills said she will look at the information to see if it seems like a legitimate sighting, then she’ll get permission from landowners before heading to check out the fireflies for herself and collect samples.

Now that scientists are getting a better idea of where populations exist, it’s creating even more questions, Bills said. Scientists are now asking questions like, what makes fireflies active earlier or later in the year? What makes them successful, and what interferes with their cycles? What species exist in the state?

“There are still a ton of questions. Just because somebody reports data to us, doesn’t mean we have a specimen in hand,” Bills said.

Katie England covers politics, the environment and courts for the Daily Herald. She can be reached at 801-344-2599 or kengland@heraldextra.com.

Katie England covers politics, county government and southern Utah County for the Daily Herald. She can be reached at 801-344-2599 or kengland@heraldextra.com.