In a Flash, Summer Love Is All Over Washington

Fireflies Get Boost From This Year's Wet Weather

This is that strange, sweet part of summer when life stops for a beetle's behind.

On a June night in Bethesda, a woman blast-e-mailed her neighborhood: "Go outside RIGHT NOW. Look into the dark." At a park in Arlington, a man clicked one flash from a penlight and waited for an insect to signal back.

This is firefly season in Washington, the best and brightest in several years. Scientists say a wet spring has made a lightning-bug-friendly region even more so, and hordes of the insects are now spending the last days of their lives floating over lawns and blinking in treetops.

In the daytime, most fireflies -- there are about 2,000 species of them worldwide, 200 in the United States -- look like a second cousin to the junebug. But at night, chemical reactions produce a glowstick light from their abdomens, each tiny bug worth about 61/407th of a candle.

This spectacle holds even more magic if you know what they're saying.

"Then the whole world of fireflies opens up to you," said Sara M. Lewis, a professor who studies the family Lampyridae ("shining ones") at Tufts University outside Boston. There is seduction and rejection, codes and code-breaking, mating and eating alive. "You can watch the dialogue," she said.

Across the country, scientists worry that firefly numbers have been driven down by lawn pesticides and sprawling concrete. Also, chemical companies have paid a per-bug bounty to get the chemicals in their tails, which are used in scientific research.

Washington has always been a good place to see fireflies. The numbers, which had seemed down, have rebounded this year -- possibly because wetter soil is more friendly to both firefly larvae and the things they eat.

"We were a little worried," said Michael J. Raupp, a professor of entomology at the University of Maryland, "but they seem to be back in force."

They provided such a show of strength in the Bannockburn neighborhood of Bethesda that a departing dinner guest pulled Jillaine Smith out of her house, to see a scene that looked like Christmas.

"They were everywhere," Smith said. "We just stood there and stared for a long while, because what is there to say?"

Then she went inside and e-mailed the neighborhood listserv: "MILLIONS of lightning bugs. The meadow is swarming with them. Go. Now."

The tiny lights shone in Virginia, too. In Alexandria a figure chased a waist-high yellow light across her yard -- driven to obsession by flashes of unrequited love.

"I'll go, like, catch a male and bring it over to the females. It's really ridiculous," said Kate Pabis, 36, a guidance counselor. "I just almost, like, feel sexual frustration for them. It's like, 'Come on, people! Let's get together!' "

In recent decades, scientists have been able to translate snippets of this firefly babel. They say the flashes are a muddle of conversations, usually several species communicating in the same meadow.

They're talking -- as animals usually are -- about sex.

The bugs in the air are all male, each flashing out a pattern distinctive to his species. The Big Dipper firefly, one of the most common here, gives a long flash while flying in a "J" pattern. Photinus macdermotti flies straight and slow, flashing twice every six seconds. Some are Morse-code dots -- blink.blink.blink. -- and some are dashes, bliiiink . . . bliiink.

Their audience is down in the grass, females who wait an interval, specific to their species, before responding with a blink or two.

"This tells the male, 'There's a female here, and let's go down an investigate further and maybe mate,' " said Jonathan Copeland, a biology professor at Georgia Southern University.

Maybe. The life of a male firefly is not easy.

In some cases, the come-hither responses are a deadly ruse, from a larger species that has cracked its prey's code. When the male flies down to investigate, this femme fatale firefly will eat it, extracting chemicals it needs to ward off the things that might eat it.

In other cases, the males have trouble finding their mates in the forest of grass blades. Or the females don't flash back at all. Recent research has shown they sometimes prefer males who flash longer and faster -- which, for reasons involving the mechanics of firefly sex, may be better mates.

They're all working with a time limit. Fireflies spend years as larvae underground and then emerge to fly only for a week or two. Their only mission is to reproduce before they die, and more than half of males will fail.

"Some males are better than other males," Copeland said. "And they advertise something in their flashes that says 'My name is Joe, and I've got . . .' " Here, Copeland described part of the male body in a way rarely seen in scientific journals.

Humans who've outgrown the fireflies-in-a-jar phase (just fine for the fireflies, scientists say, as long as the jar contains a damp paper towel and the fireflies are released at the end of the night) can bluff their way into this dialogue. Alonso Abugattas, of the Arlington County parks department, said he waits for a male to flash and then responds with a quick flash from a penlight.

"You can convince the firefly that there's a female there, so he'll get closer, and he'll do it again," Abugattas said.

The county is holding a "Firefly Festival," with storytelling, crafts and firefly hunts tomorrow from 7 to 9:30 p.m. at Fort C.F. Smith Park.

In the Fort Hunt section of Alexandria, Pabis signed up for a "Firefly Watch" program run by the Museum of Science in Boston -- and quickly found herself wrapped up in the drama of flash and response. One night, she saw female fireflies flashing alone, while apparently clueless males cruised above.

She caught one male with her and let him go right above a female.

"Nothing. She wouldn't even flash," Pabis said. "I guess they're not satisfied."

On Thursday night in a wooded stretch of northern Silver Spring, Smithsonian scientist Gary Hevel watched hundreds of fireflies cruise over his lawn and twinkle in the trees. One flew right past him, flashing and soaring.

. . . blink

blink . . . blink

In the grass, two seconds of nothing. Then,

blink. blink.

Nobody there spoke firefly. But it looked like a connection.