Dance of the Fireflies

Late June, early July is about the height of the firefly season around here. They first appear early in June—a few tentative, isolated points of light in the darkness. The season’s first flash can be startling. I may be initially misled into thinking it’s a bright star suddenly winking on, or an airplane blinking its way across the blackened sky. Then I joyously recognize that it’s the return of the “lightning bug,” the adult form of the glowworm, called by its scientific name as Lampyridae. (Isn’t that a lovely name?)

Speaking of the scientific perspective, fireflies are a beetle, with only one pair of wings—like the house fly. (Most insect pilots sport four wings.) They use bioluminescence to flash their lights—a chemical process whose efficiency humans can’t begin to approach with our advanced technology. A female lays her fertilized eggs on the ground, they hatch within a few weeks, and overwinter as larvae. The larvae may also flash from the ground—a sort of weak, slow-motion copy of what the fliers do; a wormy glow. They pupate in the spring, emerge as adults in June and then go seeking sex.

And that is what the flashing scene is mostly about: sex. (Well, it’s really about successful procreation, but we humans accentuate the erotic aspect of the procedure.) When they first appear, it’s as if they are sluggishly warming up for the coming hot flashes. The earliest fireflies light up at lazy intervals and stay lit for a good while (one to two seconds!). A neat thing happens if I have had my eyes adjust to the darkness and the bug is within a few feet of the ground: I can see a circle of light that they cast below them—like a miniature police helicopter looking for fleeing criminals. These mini-copters are silent, however, and have only sex on their minds.

As July arrives the firefly dance becomes much more lively. They crowd the air, flash much more often, and more rapidly. The activity is captivating. I can become deeply absorbed by the dance. If I look intently enough, I can follow individual flies blinking on and off, as they amble through the air. Sometimes their flashes almost synchronize, making it appear as if one bug has sped across the yard in a split second, following some erratic path.

I wonder about what amazing eyes they must have—that can withstand such brilliant flashes and not blind them. I imagine myself shrunk to a mustard-seed size, clinging tightly to the back of a firefly, getting the thrill ride of my life. Suddenly it bioluminesces, blinding me for a minute. What protective mechanisms has Nature provided its eyes? Does it blink at just the right time? Is its lit-up tail so far behind? The firefly can’t afford to become temporarily blinded and crash into a tree branch. He’s got an important mission. His chick might be waiting on a blade of grass down there, about to flash him in response. Despite being temporarily and imaginarily blinded, I picture myself hopping off. I don’t wish to be wedged in the middle of their embrace.