A Conversation about Lightning and Lightning Bugs

The other night I got up at one o'clock because I heard thunder, so I went and looked outside.                 While I had my head poked out the door, I could feel the oppressive humidity wrapping around me. I started to go back inside but stopped to admire the magic show going on above the lawn. Flashes of lightning were bobbing and signalling from grass height to treetop level. It was the nighttime love fest of the lightning bug, If you'll pardon the expression, it gave me a flashback to childhood. The sensation of the warm humid air and the aerial flashes of light reminded me of scampering around with a mason jar to make a lantern of captured insects.

Recently there has been a flurry of media alarms about the fate of the firefly, in danger of extinction. So, I wonder, what is a firefly, AKA lightning bug. I looked it up, and wow! Is it an interesting creature. There are a couple of thousand members of the family Lampyridae worldwide. New York is home to about thirty species, the most common of which is the Photinus pyralis, the common eastern firefly. These are the little guys putting on the light show outside my door.

Of course, lightning bugs are interesting because of their nighttime courting ritual, but there's so much more going on in the course of an individual life cycle. The adult form is a beetle, not a bug or a fly, regardless of what we choose to call it. The adult stage is not the only luminescent stage, either. Larva are known as glow worms because they, too, glow in the dark (they don't flash, though.) So, beyond the magic, how does this all happen, and why are these insects in such danger?

Well, bioluminescence is the short answer. Fireflies have an organ in their abdomen that contains a pigment, a catalyst, and a nucleotide that provides energy for the process of producing light. The insect regulates the flashing with adjustment of oxygen intake. So we want to know why they bother? There are a couple of reasons. One is warning to other creatures that they taste awful. The other is, of course, to attract a mate.Naturally there are exceptions. There is one type of firefly that lures members of another genus in order to eat them. And there are a few bats and birds that tolerate the taste of the luminescent chemicals.

The glow worm stage is an important one ecologically. These fierce little guys devour aphids and midges and mosquito larvae, and worms, slugs and snails. And they glow in the dark. What's not to love?

Why is such a useful and enjoyable insect in danger, then? Well, as usual, it is because of the actions of humanity. Water resources are frequently polluted by overflow of chemicals used for lawn and garden maintenance. Homeowners spray large amounts of mosquito control chemicals around their yards to control not only mosquitoes but ticks and fleas. They kill not only the target insects but every other insect in the area. Beneficials are not exempt from extermination just because their name isn't on the hit list. Every beneficial decimated or removed from an environment leaves a gap for an invasive to flourish.

“The earthbound constellations of summer” is what one observer calls them, and there is a wonderful article by Scenic Hudson Valley at https://www.scenichudson.org/viewfinder/fireflies-beautiful-but-in-need-of-our-help/#:~:text=At%20the%20moment%2C%20there%20are,can%20also%20obscure%20their%20signals. The life history of these magical little guys is unique and worth learning about.