Originally published in Castine Patriot, July 8, 2021 and Island Ad-Vantages, July 8, 2021 and The Weekly Packet, July 8, 2021
Fireflies impart mystery and magic
by Eli Forman
Perhaps no other creature imparts such a profound sense of seasonal magic as fireflies flickering across a summer evening meadow.
These curious insects are actually not flies at all but beetles; thus, a more apt moniker might be lightning bugs, which is the preferred name throughout the southern U.S. Other folk names include glowworms, moon bugs and the delightfully picturesque candlefly. Here in New England, home to roughly 15 species of firefly, the increasingly sultry evenings of June, July and early August witness the most dramatic light displays, an elaborate mating ritual for some species, a clever deceit angling for a meal for others, but is always for we humans a mysterious reminder of the strange and timeless beauty of a summer night.
Fireflies also make for great poetry fodder. English majors might recall Alfred Lord Tennyson’s “Many a night I saw the Pleiades, rising thro’ the mellow shade/Glitter like a swarm of fireflies tangled in a silver braid.”
Even though the light they produce is cold, due to the reaction of several enzymes and oxygen in a specialized light organ, it’s not passionless. Fireflies are the romantic insect par excellence and, as such, are probably also the only insect one could remotely describe as aphrodisiacal. It turns out there’s more to this than meets the sensitive eye. According to an article by Tufts University, researchers curious about how fireflies maintain such rapid flashing rates recently discovered that they use nitric oxide gas to help facilitate the transfer of oxygen though their light organ. This happens to be the same gas that allows Viagra to produce its desired effect, which leaves one wondering if there’s a secret process also going on in oysters.
Fireflies are family friendly, too. Unless you grew up on the West Coast, who doesn’t remember rollicking in the grass after fairy lights as a child? Those who have been to southeast Asia have perhaps even seen the remarkably eerie synchronous flashing species, which, to borrow a West Coast image, is reminiscent of an entire landscape of wind turbines flashing their little red lights in unison.
Locally, fireflies thrive in the moist verges between forest and field. Males fly above the vegetation, flashing rhythmically for an audience of perspective mates watching from the grass. When a titillated female flashes back, the male alights on her perch. After mating, the female lays her fertilized eggs just below the surface of the ground. The larvae feed for the rest of the summer, then hibernate below ground or under tree bark throughout the winter.
Some species are purely pollen and nectar eaters, while others are carnivorous, feeding on snails, worms and even other fireflies. Females of the Photuris species mimic other species’ response flashes, attracting mate-crazed males in order to consume them and synthesize defensive toxins from their bodies.
Habitat encroachment, which in Maine tends to mean the transition of old farm fields back to forest, and artificial light are two environmental pressures fireflies face. Although it’s unclear what impact climate change will have on these illuminating nighttime denizens, at a time when it’s best to look for silver linings, perhaps hotter, more humid summers will increase their range and brilliance. All the more reason, the next time you feel like waxing poetic, to utter softly in your beloved’s ear: “Now sleeps the crimson petal, now the white…the firefly wakens; waken thou with me.”