Find the light on fireflies

Fabulous flash dance helps boy bug meet girl bug
By Pamela H. Sacks


What “fly” is not a fly at all but a beetle? Here’s a hint: These tiny insects make meadows sparkle on a summer night.

Just about every species has unexpected characteristics that raise eyebrows and elicit comments such as, “No kidding? Is that really true?” And the firefly is no exception, says Kristin Steinmetz, a natural history guide at Broad Meadow Brook Conservation Center and Wildlife Sanctuary in Worcester and Wachusett Meadow Wildlife Sanctuary in Princeton.

Fireflies are soft-shelled beetles, and there are about 40 varieties in New England. Surprisingly, two of those varieties do not light up – which make one wonder why they are called fireflies. Steinmetz will answer that question during her hour-and-a-half program, “Fireflies: Lighting Up the Night,” from 7:30 to 9 p.m. Friday at Wachusett Meadow.

Indeed, Steinmetz will share all kinds of interesting information on these flashy little insects.

For instance, fireflies are not the only creatures that are bioluminescent, meaning they can produce light. But only a firefly can turn the light on and off, Steinmetz said.

And the purpose of the flashes? It’s a mating ritual in firefly Morse Code.
The various types of fireflies have different flashing sequences and different times in the night when they flash. The males fly and flash. Most females are unable to fly, and they stay in one spot in the grass. Females tend to be attracted to males with the brightest lights.
“He flashes and she responds with a flash,” Steinmetz explained. “If at any time she doesn’t like his flashing, she’ll stop flashing, and he’ll fly away and try to find another mate.”
There can be a dark side to the showy display of illumination. Certain types of females mimic flashing sequences to lure males of another type and then eat them.
“There’s a big war going on out there with all the flashing,” Steinmetz said with a laugh.
One of the activities Friday night will involve using a flashlight to lure male fireflies. “It should be fun,” Steinmetz said.
Steinmetz, who lives with her family in Paxton, moved to the area nine years ago. She had taught English in Washington State, but knew that, going forward, she wanted to be employed in an outdoor setting. Broad Meadow Brook offers training for guides, and Steinmetz signed up.
“The wonderful people who work there have an incredible store of information in their heads and they pass that on,” she said. “We do research on our own and spend a lot of time outside observing.”
Steinmetz grew up in New Jersey, which had an abundance of damp meadowland, the firefly’s natural habitat. She recalled that as a child she would see fireflies everywhere on summer nights. Now it seems that up and down the East Coast there are fewer fireflies.
“Think of how many damp meadows have been destroyed to make way for development,” Steinmetz said. “For those of us who live in the city or near the city, fireflies cannot compete with artificial light. They wouldn’t be able to mate enough, and they would stop existing in that area.”
Those who would like to see more fireflies in their immediate vicinity need to stop using pesticides on their lawns.
“We use pesticide to kill grubs, but, unfortunately, it kills firefly and other larva, as well,” Steinmetz said.