Fairy lights in the garden

Mars/Flickr

Mars/Flickr

As the first day of summer faded to dusk, the first fireflies of the season rose like flickering beacons from the damp grass along the stream.

Their arrival seemed early to me, since I associate lightning bugs with high midsummer, but everything has been a little off in recent years with early heat waves and unusually heavy rains. Early or late, my heart still lurches upward when first I see the little fairies of the night rising skyward.

If you were lucky enough as a child to live where the fireflies dwelt, surely you remember chasing after them, hands cupped in eager pursuit. As night fell they were everywhere, ascending from the dewy grass in waves and spirals. If you were quick and clever, the firefly was that one magical thing you could hold in your own small hand.

You had to have a firefly jar, its lid pierced with air holes, to keep them in temporary captivity. We would include a few blades of grass and a twig or two to make them feel at home while we watched up close as their mysterious lights flashed on and off. I can remember keeping my firefly jar in a darkened bedroom, watching it glow until my eyes grew heavy with sleep.

I hope never to outgrow my delight in these little lantern-bearers of the insect world -- I wish every child the chance to hunt them on a mild summer’s eve. Unfortunately, firefly populations are on the decline around the country and around the world.

They are disappearing from our marshes and fields, our yards and woodlands. Researchers aren’t exactly sure why, but development that paves over these formerly open spaces and light pollution that interferes with their flashing lights, a form of insect communication, are thought to be two causes.

It would be a shame if they faded away, since lightning bugs are not only a child’s delight, but fascinating little characters in their own right. Winged beetles during their brief adulthood, these insects are beneficial in their larval stage when they feast on such garden pest as snails and slugs. The larvae can live up to two years in the soil while adults live as few as two weeks – and may not feed at all while they mate and lay eggs.

Science has an abiding interest in these endearing little insects. Researchers use the firefly’s luminescence to track energy exchanges in human cells, a key tactic in the study of heart disease, cancer and muscular dystrophy.  The highly efficient “cool” light these insects emit hasn’t been duplicated in any commercially available light source – even the energy-saving fluorescent bulbs and LED lights come in a poor second.

Terry Priest/Flickr

Terry Priest/Flickr

Chemicals known as luciferase and luciferin (why the devilish names?) are responsible for the firefly’s glow. Adults aren’t alone in lighting up. In some lightning bug species, even the larvae and eggs can flash, especially in response to tapping or other vibrations.

The adult firefly’s beacon is, at heart, a love light. A specific sequence of flashes is intended to lure a mate and each species has a unique signal. In the sneaky way of nature, some predatory lightning bugs mimic the flash pattern of other species with another rendezvous in mind – dinner. Everyone’s got to eat!

Fireflies are found in many temperate and tropical regions; in the United States, they are found primarily east of the Mississippi in locations where the soil has remained undisturbed. In a few select places – Malaysia, for instance, and high elevations of the Great Smoky Mountains -- they are famous for putting on a synchronized show, every firefly flashing in unison. Can you name another insect activity that is a bona fide tourist attraction?

Should you want to aid the cause, there are a few things you can do to help and support your local fireflies. Leave some natural litter (rotten logs, long grass, and fallen leaves) in unused places as shelter for the larvae. Install a water feature, since these beetles need standing water in their habitats. Avoid harsh chemical in lawn maintenance programs and mow high, leaving a thick turf.

And turn off the outdoor lights, whenever and wherever you can. How can you see the fireflies if you’re blinded by the light of your own making? There are mysteries in the night, fairy lights on the wing – don’t miss them.