Almost everywhere east of the Rockies, people of my generation share some variation of the same childhood memory. In the city, in the suburbs or on the farms, a piece of green space was enough. As dusk fell on the long summer evenings, you noticed a sparkle on the grass. This was answered by another, then another, until the whole yard was alive with tiny flashes of light, “living fireworks” in the words of Sara Lewis in her wonderful book, “Silent Sparks “.
No child could resist close inspection, so chasing lightning bolts was a growing ritual. Captured lightning bolts were held in loosely closed fists as we waited for a spark of light in our hands. Some of us collected them in jars. Many of these glowing beetles did not survive the encounter, but there were always hundreds more, reappearing with every sunset for a few magical summer weeks.
The good news is that they are still there. The numbers have dwindled, but any child or adult who steps outside and looks up from their cell phone on an early July evening in Montclair might still get a taste of the magic.
It’s a romantic sight, not just for us but for the eclairs. Their show is all about love, or at least sex. To a lightning bug, your backyard at summer twilight is like a singles bar on a Saturday night.
The males circulate, flashing their lights in hopes of a flash of response from a female. The wise female stays perched low on the ground on a blade of grass or some underbrush, checking the males until she finds a flash to her liking, then timidly returning. How does she choose from all the flashy bling? Longer flashes attract his favor.
While human courtship often involves sharing a meal, lightning bugs skip this aspect of date night, out of necessity; having no mouth, they cannot eat. So what powers the show? The answer lies in the dark, carnivorous childhood of lightning.
The sparkly, charismatic bug we love is actually the brief final stage of the bug’s life, lasting a few weeks at most. The rest of their life – up to two years – was spent as larvae hiding under dead leaves, rotting logs or in the top layer of humus-rich soil.
The larvae spend this time doing what the adults cannot: eat. Their food choices are not very appetizing to human palates. Snails, slugs and earthworms are on the menu, the taste of snails and slugs making the larvae the allies of the gardener.
Hatched in late summer, the lightning bug larvae feed through the fall, pause to hibernate through the winter, then resume feeding non-stop in the spring. The cycle usually continues until the following May, when the larvae build the tiny shelters in the ground where they pupate. In June, the luminescent adults emerge, no longer hungry but looking for mates.
While the lightning bug’s dark larval stage may seem gloomy compared to its spectacular adulthood, the larvae carry a hint of magic ahead – they glow! But larval bedbugs do not seek sex. Their light serves another purpose: they shine in response to disturbance. Like the bright colors of the monarch butterfly and other poisonous insects and amphibians, the conspicuous glow of lightning bug larvae is a signal to potential predators: Don’t eat me, I’m disgusting. Their bad taste continues into adulthood. Birds offered larval or adult lightning bugs as food to avoid them, vomiting them up if accidentally ingested.
Lightning bugs are not entirely predator proof; spiders are not bothered by their chemical defenses. More dramatically, the male insects are often victimized by a “femme fatale”, a vampire firefly whose lifestyle could inspire a misogynistic Hollywood film, possibly starring Glenn Close. This vampire firefly belongs to a separate species, Photuris, whose females continue to eat into adulthood. Their diet is very specific: the males of our common and beloved Photinus species.
They use seduction to catch their prey. The femme fatale responds to male flashes of Photinus by mimicking the flash of an interested female Photinus. Unsuspecting males, approaching in expectation of love, find themselves kissed – then eaten.
If you feel lightning bugs are less common now than when you were a kid, you’re right. A recent study by the Xerces Society shows declining populations worldwide. Some factors, such as habitat destruction due to development, are beyond the control of most Montclair residents. However, there are steps we can take in our own yards to help.
Bright outdoor lights obscure blinking signals from insects and disrupt mating. Homeowners can help by turning off exterior lights at night or installing motion-sensitive lighting.
Lawn reduction is another step; adult stink bugs spend the day hiding in shrubs, tall ground covers and other perennials. Simply reducing mowing benefits lightning bugs, which prefer to rest on taller grass.
Indeed, preserving lightning bugs is a perfect excuse to save time and money on yard upkeep. Pesticides, especially when applied to the soil in the form of lawn chemicals, pose a particular hazard to grubs during their two-year stay in the soil.
And lightning bugs are all the more reason to leave leaves — or save them for use as mulch or compost. Since these insects often lay their eggs on damp leaf litter and the larvae live under leaf litter, scrubbing your garden with a leaf blower wipes out the next generation.
So if an occasional neighbor, still mired in the destructive landscaping conventions of the previous century, objects to the clover growing in your untreated, lightly overgrown lawn or the leaves from last fall lingering under your shrubs, just tell him it’s for the good of the insects. .
What former child could argue with that?
In “What’s in Your Backyard,” Sanford Sorkin and David Wasmuth alternately write about the birds and beasts you may see around your home. Wasmuth is a local conservationist and amateur naturalist. He is a Rutgers Environmental Steward and the founder of the Montclair Backyard Habitat Project. Have you seen a bird or animal you want to know more about? Write to us at [email protected].