Don’t let the light go out: Firefly population dwindling
Courtesy Peggy Butler/Pennsylvania Firefly Festival
The Pennsylvania Firefly Festival, held at Allegheny National Forest annually in June, celebrates the glowing beetle. Allegheny National Forest is one of the handful of places in North America the synchronous firefly is found.
Katherine Mansfield/Observer-Reporter
Fireflies in mason jars is a childhood memory shared by many in southwestern Pennsylvania.
Katherine Mansfield/Observer-Reporter
A firefly escapes the clutches of this staffer’s husband catching the golwing bug, leaving light trails in its wake.
If you step outside at night during June and July, the flickering glow of fireflies – the official insect of Pennsylvania – produces a magical summer spectacle.
Call them what you will – fireflies, lightning bugs, glow worms – but the bioluminescent insect actually is a beetle, in the family Lampyridae.
Dr. Ainsley Seago, associate curator for the Section of Invertebrate Zoology at Carnegie Museum of Natural History, had a firefly-free childhood growing up near Seattle, and now is fascinated by them.
“What isn’t fascinating about fireflies?” asked Seago. “They’re little floating points of light in the summer night. They’re adorable bugs with light-up butts that speak a secret language of flashes and blinks.”
Like other insects including bees and butterflies, the firefly population is declining globally.
Seago said the decrease is due to several factors, including pesticide use, loss of natural habitat, climate change, and light pollution.
There are about 2,000 species of fireflies worldwide, including a couple dozen species in Pennsylvania.
“We have spectacular firefly diversity here,” said Seago, noting there are six commonly seen species in southwestern Pennsylvania.
Allegheny National Forest is home to more than 15 species, and it is one of the few places throughout North America (Tennessee and South Carolina are others) where synchronous fireflies – male fireflies who synchronize their flashing light pattern – can be found.
Firefly tourism is a fast-growing industry in the United States.
The Pennsylvania Firefly Festival holds its annual event in Kellettville, near Tionesta, the last week of June, which coincides with the mating season of fireflies in the Allegheny National Forest.
Peggy Butler, secretary and co-chair of the Pennsylvania Firefly Festival and member of the U.S. Firefly Tourism Luminary Council, said an estimated 1 million ecotourists travel each year to witness fireflies’ light shows.
The two-day festival, which was first held in 2013 – the year after scientists from the Firefly International Research and Education team confirmed the presence of synchronous fireflies in the forest – limits visitors to 50 people each night.
“We didn’t think people would be interested in a firefly festival, but we were wrong. More and more visitors flocked to the area,” said Butler.
The festival’s popularity was both a blessing and a curse.
“Our concern was that the impact of tourists’ activity was going to endanger the species we have there,” said Butler. “The very thing people wanted to see was going to be destroyed by encroaching on their habitat.”
Firefly flashes are used to attract a mate.
Each species will flash in different sequences – a code, if you will – to make sure they find the right partner.
Artificial light, Seago said, wreaks havoc on fireflies’ nocturnal courtship.
A campaign called “Lights Out for Lighting Bugs” encourages people in firefly habitats to turn off outdoor lights.
Seago suggested other actions, including cutting down on mowing (fireflies spend time on the ground during the day), planting native trees and grasses, and planting firefly-friendly gardens.
Fireflies’ glowing light – called bioluminescence – is the result of a chemical reaction that produces light, but doesn’t make heat. It’s another firefly fact that impresses Seago.
“They figured out how to create light without heat millions of years before humans even learned to build a fire,” she said. “How could anyone not find that interesting?”
The life span of an adult firefly is brief, about two to four weeks.
“Their purpose is to find a mate and procreate. Not all species even eat when they’re adults,” said Butler. “Their function is find a mate, then they lay their eggs and then they die.”
But their brief and extraordinarily bright lives bring wonder to children and adults alike, and create memories.
Christie Campbell of Washington recalled the time her granddaughters visited from Colorado and saw fireflies for the first time. “I got them jars to catch them in so they could go to sleep with them in the room,” Campbell said. “Good memory.”
Note: The Pennsylvania Department of Conservation and Natural Resources, Mass Audubon, and Tufts University is encouraging citizen scientists to participate in a Firefly Watch Community Science Project.
Participants are asked to sit outside for 10 minutes once per week through the end of lightning bug season and collect information on the fireflies they see in the yard.
Then, submit the data to Mass Audubon, a Massachusetts-based conservation organization. Visit massaudubon.org for more information. The watch run from now until August and anyone in North America can participate. Mass Audubon is seeking to learn about the geographical distribution of fireflies and what environmental factors impact their numbers.
For information about the Pennsylvania Firefly Festival and to subscribe to its free quarterly newsletter, visit pafireflyevents.org.