Fireflies Attract Experts, Observers and Mates

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(Host) One of the most familiar sights of a summer evening is the flashing of lightning bugs hovering over lawns and meadows. But there’s more to a firefly than meets the casual eye. Recently, a group of Vermonters curious to learn more about these luminous insects recruited the help of a firefly expert.

VPR’s Steve Zind reports.

(Sound of people getting out of car.) “Mosquito heaven! You can just hear them talking over there. They said, ‘Hey, the food’s arrived.'”

(Zind) One evening last week, while many Vermonters watch fireworks, a small group of people braves swarms of mosquitoes at a remote meadow in Marshfield. They’re here to look at fireflies.

(Jim Lloyd) “What’s the most distinctive species you see out there?”
(Observer) “Obscurelis?”
(Llyod) “Absolutely! Photinus Obscuralis. And this is the double and triple copper colored pulsar, fairly low.”

(Zind) Instructing the group is University of Florida entomologist Jim Lloyd. Lloyd is the world’s foremost expert on fireflies.

(Lloyd) “They’re beetles of the family Lampyridae, but who cares! We call them lightening bugs. We call them fireflies. If you were in Jamaica, you might call them peenie wallies or blinkies.”

(Zind) When Lloyd arrived last week, there were 19 known species of fireflies in Vermont. Now there are 21. In short order, he identified two more varieties that had not been spotted before in the state. Lloyd says there are probably thousands of species worldwide yet to be catalogued. That’s what drew him to fireflies forty years ago.

(Lloyd) “The birds and the snakes and those things that I got interested in had all been done a hundred and fifty years ago. And the fireflies – not much was known about them as far as their species or what their signals were, so it was wide open. So it’s just been a life.”

(Zind) When the sun goes down male fireflies take wing. Their flashing is all about courtship. They signal to females who wait in the grass, answering the males with a languorous blink or two. There are subtle differences in the color of the light emitted by different varieties of lightning bugs: from a waxy yellow to lime green to a coppery glow. The males of each species have their own unique semaphore: a Morse code of dots and dashes.

Most fireflies look pretty much the same, so identifying these patterns is the surest way to pinpoint a particular species. But it’s not easy. It takes a keen eye, a stopwatch to time the intervals between flashes, and a thermometer. The higher the temperature, the faster fireflies flicker. Lloyd also uses a light mounted at the tip of a stick. He attracts male lightning bugs by impersonating the blink of a female.

(Lloyd) “What you do is you take your fish pole and when one gives a dot, you put the tip of your fish pole with the light on it down in the grass and you give him an answer.”

(Zind) Lloyd says a firefly in Vermont might flash a little differently from one of the same species in Massachusetts. He says these kinds of regional firefly dialects have developed because populations of fireflies are often isolated by mountains and forests. Fireflies may seem defenseless, but Lloyd says some are poisonous, especially for small reptiles or amphibians looking for a meal.

(Lloyd) “And they taste terrible. Put your tongue on a firefly. You won’t like it!” (Laughs.)

(Zind) Lloyd says catching them in a jar can be dangerous to fireflies’ health. He suggests keeping fireflies confined for just a short period before releasing them again.

For Vermont Public Radio, I’m Steve Zind in Marshfield.

(Observers) “Whoa! What’s that darting by really quickly? (Exclamations.) Did anyone see the flash pattern?”

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