Blink. Flash. Blink. July is almost over, and the fireflies are out in full force. The luminous bugs are blinking their way across our yards, calling many of us to chase them. One expert who can be found hunting fireflies these summer nights is Bill Reynolds, curator of the Arthropod Zoo at the North Carolina Museum of Natural Science.
“A lot of folks don’t realize that a firefly not a fly at all. It’s actually a beetle,” he said, pulling his collecting kit and insect nets out of the back of his truck. “There are a lot more different types of them out there than people would think.”
More than 2,000 species, to be exact, according to Paul Labadie, a research technician in the entomology department.
It is dusk, and Reynolds is at the Rose Garden, a few blocks from N.C. State’s campus, for a lesson in calling fireflies.
“The most common species of fireflies in this area is probably Photinus pyralis, so that’s who we’re going to call tonight,” he said.
According to Reynolds, a firefly’s flash is actually a mating call. The male flies through the air, blinking to the females in the grass. The female recognizes the male’s blink and responds to him, with her own flash, from the ground until the male finds her.
Their glow is the product of an enzymatic reaction in special lantern cells inside the insect’s abdomen.
“It’s a unique reaction in that it is completely cold,” Reynolds said. “As a comparison, most of the energy produced in a light bulb is actually heat. Only a small percentage of the energy is light. That’s why light bulbs are hot to the touch. In a firefly’s flash, almost 100 percent of the energy output is light. There’s no fire in a firefly.”
Reynolds reveals a small key chain flashlight. The hunting begins.
“Because the male flies around, I’ll pretend to be the girl firefly. The trick is to wait two seconds after you see him flash in the air before you flash back,” Reynolds said. “If I’m even a second off, he’ll think I’m an imposter.”
He sees a firefly flash in the shadows of the roses. Reynolds counts to two and flashes back, holding his flashlight over his palm. The firefly responds, hovering a little closer. Reynolds counts to two and answers him. Two more flashes, and the male firefly lands on Reynold’s hand, searching for his mate. After a while, the insect realizes he’s been duped and flies away.
“There might be easier ways to catch fireflies,” Jessica Lawrence, a doctoral student in entomology, said as she watches children run around the garden, grabbing fireflies out of the air with their hands, “but this is definitely the coolest.”
