FIREFLIES: A magic of childhood is disappearing

‘A dark night, lightened
up by thousands of glowing
fireflies... It’s magical...’
– Ama H. Vanniarchchy

By Charles Winslow

SISTERSVILLE – Maybe it’s because of the late spring this year, but I have seen only about a handful of fireflies in my yard so far. I hope more will eventually show up.

As most every child knows, fireflies, also known as lightning bugs, are fun little creatures capable of putting on their own light shows during warm summer evenings. Walking through a field at night, surrounded by a sea of the little flashing greenish-yellow lights is nothing short of magical.

Fireflies (Lampyridae) are winged insects belonging to the beetle family. Their flashes are a result of bioluminescence, meaning they produce a cold light using chemicals their bodies naturally produce. The insects are highly efficient; their lamps don’t generate any waste heat or produce infrared or ultraviolet frequencies.

These little critters have developed their unusual way of communicating both to attract mates and to warn off prey. Unlike the annoying and loud cicada, fireflies are not tasty little treats for other animals. They contain chemicals that make them taste bitter and are harmful to some that may try to eat them.

Want to participate in WVDNR's 2024 firefly sighting survey?

The male’s flash pattern is believed to communicate to which species he belongs and the intensity of his light may show his suitability for mating. Here in the Ohio Valley there are somewhere between 23 to 41 species, with each having its own unique luminescent signature.

The mating ritual includes a male flashing his desire to mate with a female of his own species and the female reciprocating with the same flash pattern. Sounds simple enough, right? But love, even in the bright little lives of the firefly, can be complicated.

Females of the genus photuris are known to mimic the flash pattern of the phorinus, to whom they are closely related. When the male comes for a visit, he is attacked by the female and eaten. The male photuris are also known to mimic the male photinus’ signals to trick the females of that genus into mating with him.

Not to be outdone, scientists have discovered that some photinus males will imitate the flash pattern of a photuris female to confuse them. Instead of chasing down a suitable and receptive female the male photuris discovers there’s a male waiting for him. The male photuris is then reluctant to approach real females for fear it may be just another RuPaul of the firefly world. That, of course, reduces competition.

While scientists know firefly larvae are carnivorous and will eat snails and worms, little is known about feeding patterns of the adult firefly as they live only long enough to mate and lay eggs. Once the eggs hatch, the larvae will live underground until they emerge into adulthood the next year.

Fireflies can be found all over the world; they generally live near standing water and most species live in long grasses and wooded areas. In North America, however, very few of the glowing insects are found west of Kansas.

Firefly populations are in decline for reasons not clearly understood. Some reduction is clearly linked to the loss of their habitat, with fields developed for commercial and residential purposes. Mowing lawns, where fireflies spend the day, also reduce the population.
Some of the losses are thought to be linked to the increased use of certain pesticides.

But scientists also believe fireflies are in decline because of light pollution. Fireflies communicate by flashing their lights. Artificial lights from cars, homes, stores and street lights may be making that communication more difficult, reducing the amount of offspring born each year.