DELAWARE SEASHORE STATE PARK, Del. — On a muggy July evening, Delaware state biologist Jason Davis is doing what kids have done for ages: Trying to catch a firefly. It’s nowhere near as easy as the summer evenings of his own childhood, with only a few in this large wetland between a bay and the Atlantic Ocean.
Davis sees the double flash of a male and chases after it. It zags west. Davis follows. It zigs back east. Davis says the bug seems to be toying with him: “I think they’re having fun.” Finally, he flicks a long net to snare what some people call a lightning bug.
“That was four years of high school lacrosse,” he says.
The firefly that Davis chased, the Bethany Beach firefly, is so rare that it’s likely to become the first of America’s fireflies to be put on the Endangered Species List later this year, experts said. It’s in trouble due to rising seas from climate change, and rising housing developments. Davis and others estimate no more than 1,000 are left.
For many Americans, the flash of the firefly calls up memories of summer childhood evenings gone by — and now, the worry that the bugs are disappearing.
Fireflies once seemed plentiful and cool, easy to catch and watch, serving as an introduction to the world of nature around us. In the past few years, entomologists kept hearing anecdotal reports of fewer fireflies, leading to fears that the summer flash was fading with habitat loss, pesticides, light pollution and climate change.
But they had no data. And the most common firefly, nicknamed the Big Dipper because of its swooping flight path, is thriving. The fireflies of many eastern and midwestern U.S. childhoods “have survived everything we can throw at them,” said Tufts University biologist and firefly expert Sara Lewis.
But other species are troubled, and the Bethany Beach type isn’t the only one at risk of blinking out for good.
“They’re too important for us to lose, but they’re too small for us to notice,” said Sergio Henriques, invertebrate conservation coordinator at the Indianapolis Zoo.
Every U.S. state but Hawaii has fireflies. Different species come out at different times of night and summer. They flash or glow in their own ways. Urban areas with bright lights and not enough proper habitat can make them hard to find, but scientists have created a map of where to look, said Candace Fallon, a conservation biologist at the Xerces Society for Invertebrate Conservation.
A couple years ago scientists finally took stock of America’s 170 documented species of fireflies. Or tried to. They concentrated on trying to determine the health of 130 species and of those “we discovered that about 50 percent of them, we don’t know enough about them to even make a guess. They could be doing really well. They could be extinct, for all we know,” Lewis said.
“It’s kind of like we’ve taken fireflies for granted for many decades,” said Delaware State University environmental sciences professor Christopher Heckscher, who rediscovered the Bethany Beach firefly in 1998 after it had been lost for 30 years. “Everybody just assumes that we know all about them and that we know all the species and that everybody loves them. You know, they’re bioluminescent, so that’s really cool. Kids love them. But it’s amazing how little we know about them.”
About one-third of the 130 species surveyed in the U.S. and Canada are doing fine, but about 18 are in trouble, Fallon said.
Fireflies are special, Lewis said.
“Everybody loves them. Even people who hate insects,” Lewis said. “They are the absolute best ambassadors for natural magic.”
