WASHINGTON — As “unofficial summer” ends, some in the area say they missed out this year on a warm weather joy that people have loved for years — the fleeting, warm glow of fireflies.
“Absolutely we’ve had mixed reports of firefly activity this year — some people in Maryland have said they’ve seen none whatsoever,” said Michael Raupp, professor of entomology at The University of Maryland. “My experience in Columbia, Maryland, was we had a pretty good year for fireflies.”
Fireflies flourish during summer, said Raupp.
“These guys got off the ground in June, they were strong through the Fourth of July,” said Raupp. “I saw my last firefly a couple of weeks ago, and certainly by September they’re gone.”
The limited light shows are natural, said Raupp.
“That’s just how they go, that’s their season. They’re done now, so please don’t expect to see any more fireflies this year, but hopefully, we’ll keep our fingers crossed and we’ll see more next year,” he said.
Firefly researcher Ben Pfeiffer, founder of educational resource Firefly.org, said people always smile while remember seeing fireflies as a child.
“It’s something that captures our imagination, and our sense of wonder,” said Pfeiffer.
Pfeiffer’s website focuses on dwindling firefly populations, and what can be done to preserve them.
Raupp and Pfeiffer agree the biggest threats to fireflies, other insects, and wildlife in general, is habitat destruction.
“As we transition things that were once meadows, or forests into developments and lawns, we simply change the ecology of these places, and we see a loss of biodiversity,” said Raupp.
While most people are familiar with fireflies, or lightning bugs, emitting light to attract mates while they flit about, in some cases the glowing begins before they’re capable of flying.
Pfeiffer said in some species the larvae and eggs give off light, with some eggs flashing in response to gentle tapping or vibrations.
“Some people don’t know the immature stage of fireflies are actually voracious predators that live in the soil and consume many other insects,” said Raupp.
“As we change the ecology, if that habitat for the immature fireflies isn’t proper, we’re simply going to see a reduction in firefly populations.”
Pfeiffer said fireflies don’t easily migrate to other areas, and new development can stymie a neighborhood’s population.
“They put in a lot of concrete. Those fireflies won’t come back because you basically bury the larvae in the ground,” Pfeiffer said.
Anecdotal evidence shows light pollution may be causing firefly populations to dwindle.
“These guys depend on their flash patterns and correct interpretations to get together and mate, so if we have a lot of interference from unnatural light this could cause disruption,” said Raupp.
“It basically messes with their ability to see each other.”
While a cause and effect hasn’t been proven, Raupp said previous studies have shown other insects are affected by artificial bright lights at night.
“There’s probably better evidence for mating disruption of our big silk moths than there is for fireflies at this point in time,” he said.
Despite the tenuous firefly population, Pfeiffer still encourages catching the lightning bugs.
“I tell kids to catch them, because the only way they’ll learn what they are is if they’re able to handle them,” he said.
Using a net helps capture them in mid-flight.
Pfeiffer said poke a few holes in the top of a plastic jar, and place a paper coffee filter moistened with non-chlorinated water inside the jar.
“While most adult fireflies don’t eat, they’ll suck up some moisture in order to sustain themselves,” he said.
A firefly might live for a week in a jar, but Pfeiffer said with dwindling populations, every firefly counts.
“After you caught a few in a jar, let them go that evening so they can reproduce, and come back next year,” Pfeiffer said.
See how well you know fireflies with our little quiz:
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