My eyes were glued to the western sky as I searched the darkness for incoming lights. Although it was the fourth of July, 2021, I wasn’t watching a fireworks display, nor was I looking for an incoming plane. Yet, there I was at the north end of my woodland clearing in pitch blackness at 1:00 a.m., looking for yellow lights.
Before long, I spotted a familiar glow about 20 feet (6 m) above the ground. As soon as the series of eight pulses ceased flashing, I jiggled the power cord in my hand, causing the little yellow-green light on my light emitter to rapidly flash twice.
I had placed the emitter on the ground with hopes of drawing in a male synchronous firefly by imitating a female of the species with my blinking light. As the male firefly drew nearer, I repeated the jiggling process.
After about a minute, I shone my flashlight on the light emitter…and there he was crawling around on top of it! But wait a minute—what was it? I later discovered that this was not the firefly species I had expected! It was, in reality, a large predatory firefly called Photuris lucicrescens. The females of that species mimic the blinking lights of other female firefly species, then feed on the unsuspecting males that are lured in. That was another new firefly to me, one which I never knew even existed!
Fireflies are living lights, and the scientific word is bioluminescence. What an intriguing word that is! It is a marvelous ability that the Lord has created into some of His creatures, fireflies and certain sea creatures in particular. In the firefly, the key light-producing component is the organic compound luciferin.
Concerning the firefly beetle, it’s all about light. From egg to larva to pupa to adult—each stage shows some degree of bioluminescence. The adults communicate by way of light. Firefly larvae are often referred to as glowworms and are beneficial, as they feed on snails, slugs, and other insect pests. Fireflies live most of their lives as larvae (from one to two years) before pupating and changing to adult beetles, living out the remainder of their short two-to-three-week adult lifespan.
I have childhood memories of catching fireflies. And this year my fascination with them was rekindled, when, about ten days ago, I decided to photograph them. My first photograph really piqued my interest, because I noticed that there were two distinctly different firefly light colors and patterns captured in my photograph. This prompted my quest to figure out what they were.
The interesting thing I discovered was the presence of a predominant firefly species on my property which I didn’t know even existed! The experts say that there are more than two dozen firefly species in Ohio. But I have learned from my many hours of observing them both here in eastern Ohio and in western West Virginia, that there are two predominant species in these parts. The first is Photinus pyralis, called the Eastern firefly or “Big Dipper.” This is the species I have always seen around my yard at sunset and into the first part of the night. They remain lighted for a fairly long time and often fly in a dipping pattern. They usually appear as long green streaks in photographs.
But it wasn’t until I ventured into a moist section of my woods after midnight, that I discovered the new-to-me species…Photinus carolinus, also called the synchronous firefly.
This species is extremely interesting because of their synchronous nature. When one firefly begins lighting, they all light up (almost instantaneously), usually with a series of four to eight light bursts at half-second intervals. Then they all synchronously go dark for about four seconds…and then the process begins all over again! I had never seen such a light show, and it is absolutely amazing!
So, here’s what’s happening. All the male fireflies in the sky are blinking to make their presence known to the females, which are either on the ground or in short vegetation. During the dark synchronous time, the receptive females each respond to the males’ light displays with a quick doublet flash.
Synchronous firefly flashes are brighter and more yellow than the Eastern variety. They appear as short yellow (mostly horizontal) pulses in photographs.
Both Eastern and synchronous fireflies seem to enjoy moist areas, and I saw them together many times in the same woodland locations. But the yards and fields near my home belong primarily to Eastern fireflies. Synchronous fireflies like tall poplar, oak, and maple trees and are very active in my woods from midnight to 3:00 a.m., well after Eastern firefly activity tapers off.
At the waterfall in West Virginia, I found few fireflies at the falls itself compared with the number of fireflies above the falls where the water was calmer. At that very moist location, I noticed a slightly greater number of Eastern than synchronous fireflies, and there the number of Easterns remained strong until the time I left the falls at 2:30 a.m.
Peak firefly season is short-lived in Ohio, from around the third week of June to the first week of July. But I’m so thankful that I took the time to learn more about these beautiful creatures. I hope you take time to discover the fascinating world of living lights in your neck of the woods.