07/18/2019
By Gabrielle L. Wheeler
The kids and I spent the 4th of July enjoying fireworks, except it was natural fireworks and not explosive fireworks. No, we didn’t go to watch a display, instead, we caught fireflies in our front yard and enjoyed the light show these insects put on.
Fireflies compose the Lampyridae family, a member of the beetle order. While many animals that have amazingly special attributes tend to be plain looking, local firefly species can produce light in their bodies and are also interesting to look at. These little insects have hard, black wing casings, or elytra, usually edged in white or yellow, and a red head. Striped antennae help them navigate. Fireflies also have a stream-lined appearance in my opinion, and a matte finish to their wings.
The ability to produce and emit light by a living organism is called bioluminescence. There are only a handful of organisms in the world that we know of that produce bioluminescence in comparison to the staggering number of lifeforms alive today. Examples of other organisms that produce bioluminescence are some deep-sea fish, jelly fish, and the larvae of the fungus gnat Arachnocampa of Australia. In fireflies, bioluminescence is a chemical process that results in illumination of the lower abdomen. In some species of fireflies, both male and females produce light, in others the males only. This is displayed as a blinking light, which can be green, yellow, or more orangish.
It is now understood that most species of fireflies produce light to attract and locate mates. In some species, males develop their own unique flashing sequence, then fly around hoping to catch the attention of a female. Once this happens, the female flashes back so that he can locate her. After a quick introduction, mating occurs, and the rest is history.
Firefly numbers are dropping world-wide and scientists are racing to figure out why. When I was a child living in town, I remember summers with dense populations of fireflies in my father’s back yard. Now, that is just a memory and finding even one there is a rare sighting. My current house in the woods has some fireflies, but nothing like I remember from my childhood. Why is this? Some sources say it could be due to development of rural areas to urban or merely human management of rural countryside. Others speculate light pollution produced by houses and cars may affect the ability of fireflies to successfully locate mates. Let’s hope they figure out the answers before we risk losing this amazing little insect that puts on its own light show.
