Fireflies are the topic of my story on the cover of the New York Times science section tomorrow. It’s the result of a visit I paid last Friday evening to a meadow in Massachusetts, where I listened to Sara Lewis of Tufts University explain the sultry, complex tale of sex, deception, and death that was playing out in front of me.
I first got to know Lewis’s work last summer, when I decided I wanted to include fireflies in my next book, The Tangled Bank: An Introduction to Evolution. Lewis co-authored a fascinating review of firefly biology last year (free pdf from Lewis’s web site). I particularly liked this chart, which shows how different species have evolved different flash signals.
The male, flying around, releases a certain pattern of flashes–a single one second pulse followed by a five secondin the case of Photinus pyralis, for one example. And if a female P. pyralis, sitting on a blade of grass, likes what she sees, she responds three seconds later. Not one. Not six. Three. If she responds at the right interval, he knows he’s found a female of his own species and zeroes in, sending more flashes. She may also be signalling other males at the same time; which male she chooses may come down to subtle features of the flash pattern–for example, a rapid series of pulses as opposed to a slow one.
You can, as I discovered, speak their language with a penlight. You can even play the male or the female, depending on your mood.
There’s lots of strange business going on out among the fireflies. I didn’t have room in the article to describe some of Lewis’s new areas of research. Because female fireflies mate with several males, they can end up with sperm from several males inside them at once. Studies on other animals have suggested that females can choose which male’s sperm they’ll use to fertilize their eggs. Males can also inject chemicals with their sperm that increase their odds of fertilization. It’s clear that in many species, female preferences and male competition can continue after mating ends.
No one knows how this struggle plays out in fireflies. Adam South, one of Dr. Lewis’s graduate students, is investigating this side of the evolutionary equation. He is mating female fireflies with two males apiece and then collecting the eggs they lay. Using DNA tests, he’s determining the paternity of the eggs. Perhaps the males with more attractive flashes have more offspring.
What scientists like Lewis know about fireflies is remarkable, but it’s dwarfed by what they don’t know. Are fireflies on the decline, for example? Unfortunately, there’s no good long-term data. But that’s now an opportunity for some citizen-science you can get involved in. Lewis and some former students have helped organize Firefly Watch, based at the Boston Museum of Science. You can make your backyard part of biology’s new frontier.
Related Topics
Go Further
Animals
- This ‘saber-toothed’ salmon wasn’t quite what we thoughtThis ‘saber-toothed’ salmon wasn’t quite what we thought
- Why this rhino-zebra friendship makes perfect senseWhy this rhino-zebra friendship makes perfect sense
- When did bioluminescence evolve? It’s older than we thought.When did bioluminescence evolve? It’s older than we thought.
- Soy, skim … spider. Are any of these technically milk?Soy, skim … spider. Are any of these technically milk?
- This pristine piece of the Amazon shows nature’s resilienceThis pristine piece of the Amazon shows nature’s resilience
Environment
- This pristine piece of the Amazon shows nature’s resilienceThis pristine piece of the Amazon shows nature’s resilience
- Listen to 30 years of climate change transformed into haunting musicListen to 30 years of climate change transformed into haunting music
- This ancient society tried to stop El Niño—with child sacrificeThis ancient society tried to stop El Niño—with child sacrifice
- U.S. plans to clean its drinking water. What does that mean?U.S. plans to clean its drinking water. What does that mean?
History & Culture
- Meet the original members of the tortured poets departmentMeet the original members of the tortured poets department
- Séances at the White House? Why these first ladies turned to the occultSéances at the White House? Why these first ladies turned to the occult
- Gambling is everywhere now. When is that a problem?Gambling is everywhere now. When is that a problem?
- Beauty is pain—at least it was in 17th-century SpainBeauty is pain—at least it was in 17th-century Spain
- The real spies who inspired ‘The Ministry of Ungentlemanly Warfare’The real spies who inspired ‘The Ministry of Ungentlemanly Warfare’
Science
- Here's how astronomers found one of the rarest phenomenons in spaceHere's how astronomers found one of the rarest phenomenons in space
- Not an extrovert or introvert? There’s a word for that.Not an extrovert or introvert? There’s a word for that.
- NASA has a plan to clean up space junk—but is going green enough?NASA has a plan to clean up space junk—but is going green enough?
- Soy, skim … spider. Are any of these technically milk?Soy, skim … spider. Are any of these technically milk?
Travel
- Could Mexico's Chepe Express be the ultimate slow rail adventure?Could Mexico's Chepe Express be the ultimate slow rail adventure?
- What it's like to hike the Camino del Mayab in MexicoWhat it's like to hike the Camino del Mayab in Mexico