LEXINGTON, Ky. (LEX 18) — As the sun sets on sticky summer evenings in June, tiny, hovering blinks fill the sky. They first start off in the shadows and the trees, moving out into the open while daylight turns to dusk. These lights, of course, belong to fireflies.
“It is just an iconic piece of summer,” said Jonathan Larson, an extension entomologist at the University of Kentucky. “It's something that I think a lot of people have a lot of love for. They don't cause problems. They're just interesting-looking insects, and they do a weird thing. Their butts glow. I mean, how, how hard is that to love?”
From late May to early July, fireflies begin their daily process of flying around at dusk to signal one another.
“The male is flying through the air, he's making a blinking pattern, sometimes making a flying J pattern depending on the species,” Larson said. “Then there's a female down on the grass below that's signaling back, and then he'll fly down to find her and mate.”
In recent years, people have reported that they feel there are fewer fireflies coming out. Is there any truth to that, though?
“In the normal American backyard there probably are fewer fireflies that people are seeing,” Larson explained. “This is just going to boil down to logistics of how that place was built, what's happened to the natural habitat around that suburb, around that apartment building, around that town, and some of the things that we may strip out and alter about the landscape are going to decrease the number of fireflies that can persist there.”
According to Larson, firefly numbers are on the decline. However, it follows a larger pattern with insect life overall.
“I would say they're declining in the same fashion as other insect life,” he said. “It's probably more noticeable because they do glow, and there's something that people are on the lookout for.”
Because of their status as an ‘iconic’ bug, people are more aware of a decrease in fireflies, even though there are contributing factors that affect all insects. One unique factor that affects fireflies – but not other bugs – is light pollution. Bright, continuous lights can inhibit the ability of fireflies to see other signals.
“If it's too bright outside, they can't see that glow,” Larson said. “They're not going to be able to facilitate that mating.”
Despite the decline, there are a few ways that you can contribute to the fireflies, helping bring them back to your backyard.
“One big thing is to get lights that are motion activated on your property rather than constant security lights that are always on,” Larson explained, adding that directional lights are also better than lights that illuminate large spaces for long periods of time.
“We can also replace parts of our lawns and landscapes with firefly habitat. This would be kind of thicker, bushier grasses that you're planting, taller grasses that are going to grow up about waist high, places that will be far less managed than a typical lawn. You can put kind of logs and things in there, things that'll help them to have places for their eggs to be hidden.”
“In those ways, we can help their numbers to try and bounce back up a little bit so we can all keep enjoying these summer flashes that we all love so much.”
