Fireflies or Lightning Bugs?: by Tina Clinefelter

For the past few evenings I have been delighted with the show put on by thousands of lightning bugs as they dance outside my new living-room window. Is it just romance on their minds or do some have a deadlier purpose – we’ll get to that burning question in a while; first I need to pass along the facts I garnered at 3:00am this morning when sleep eluded me and the computer was still awake!

Lightning bugs are winged beetles of the order ‘Coleoptera’ and occur worldwide except for the coldest regions. There are many species and sub-species and most are nocturnal; the majority of the diurnal species do not produce light.


The life cycle of our most common, local variety is thus: after mating the female deposits her eggs in the ground where they hatch into a grub (larva) with the ability to produce light as a warning to predators that they possess really bad tasting chemicals in their bodies. This is the ‘glow worm’ stage. The larvae feed on worms and slugs by injecting them with a fluid that immobilizes the potential meal; at the end of summer the larvae overwinter in hibernation, pupate in early spring, developing to adulthood in late spring/early summer when the cycle begins again.

Now let’s explore what is known about the lightning bug’s ability to produce ‘bioluminescence’ which it uses to attract a mate or prey (told you there was a dark side to these light-producing insects!)…Bioluminescence is a ‘cold’ light, that is, it has no infrared or ultraviolet wavelengths, and is 100% efficient in producing light – no heat! By contrast an ordinary electric light-bulb produces 10% light and 90% heat! The firefly ‘flashes’ are chemically manufactured in the abdomen when oxygen is combined with ‘luciferin’ in special cells and this involves enzymes and proteins and as I am a gardener not a chemist, this is as far as I go with the most commonly accepted theory and I’m sticking with it!

Here we get to the dangers of being a male firefly; in the normal sequence of mating behavior, the males are aloft flashing a constant light pattern attractive to females of his species; the females are usually on the ground watching for a particularly enticing male – the flashes match and the game is on! But sometimes the ‘femme fatale’ flashes a different species signal and reels in a nice snack. This tactic is called ‘mimicry’ and the only explanation I can imagine is that the lady didn’t get enough flower nectar during the day!

If you would like to create a lightning bug paradise in your back yard, here’s how: eliminate all lawn chemicals; darken the area as too much light interferes with mating activity and let the grass grow lengthy to provide cool daytime areas for resting. Do kids still collect fireflies in a jar and watch them perform? Bet not!

Most of you know of my affection for alliteration – here’s a beaut…
Clinton County Fairground Farmers’ Market – Fleas, food, fun, friends, family, farmers, French fries! (Tuesday 8:00am to 4:00pm) Be there or be square!
BTW (by the way) what do you call them – lightning bugs or fireflies?