Adult fireflies live for only about two weeks, an urgent frenzy of flashing in a desperate effort to find a mate. The eggs that females lay hatch later in the summer; the larvae overwinter and then usually pupate the next summer. The larvae also glow, although more dimly and without the rhythmic flashes, possibly as a warning to predators that they’re toxic. Scientists have removed the light-emitting organs from the larvae, only to find that when those larvae become adults, they can still light up just fine. That means, says Sander, that they create a brand new light-emitting structure between their larval and adult stages.
Sander has collected seven fireflies tonight. She will pair up some of them up to see if they’ll produce larvae to raise in captivity. “I’ll put the female in with this male and see if we get babies,” she says. “Or, if she eats him. Sometimes we get both.” These fireflies are of a different species than those in the genome project, but Sander and a collaborator hope to use the new larvae she produces this summer to study other aspects of firefly genetics.
At Amherst, Sander also studied flying, flashy creatures: not fireflies, but hummingbirds. “I’m a sucker for charismatic organisms,” she says. Assembling the full firefly genome will make use of her Ph.D. work, which involved looking at shorter segments of the firefly genome. She’ll also be in charge of making sense of the genome, by taking the long strings of letters that represent nucleic acid and figuring out where each gene is and what it does.
Grants for this kind of research are hard to come by, which is one reason Sander and her team chose to pursue crowdfunding. But there’s a second reason, she says: “We thought it was a great way to reach out to the wider community, scientists and nonscientists, and involve them and show them what we can do with their support.” Many of their backers sent detailed messages about how much they have loved fireflies since childhood.
By now, the light has completely faded from the moonless sky. Apart from Sander’s headlamp, the blinking bugs are the only source of light. On a warm night such as this, they might keep flashing past midnight. At the parking area we stop to admire the lights. The trees look like a Christmas display. “People don’t go outside in the dark,” Sander tells me. They perceive the darkness as full of threats and unpleasant bugs. That may be true, but it’s also full of strange and mysterious beauty—beauty that Sander’s research is helping to make a little less mysterious.
Want More Fireflies in Your Yard?
IF YOU WANT more fireflies in your own yard—and who wouldn’t? —try turning off outdoor lights at night, reducing the amount of pesticides you spray on your lawn and letting your grass grow a little longer in the summer. Or, better yet, leave parts of the lawn totally unmowed. But no need to overthink it. “Best practice is just: turn out all your lights, go out on your porch and watch,” says Sander. In the words of a fellow firefly researcher, Lynn Faust: “They are one of the few insects we are not trying to kill,” thanks to the “beauty and mystery and awe” that they offer the world.