Recently we had the pleasure of having several of our granddaughters visit us for a few days. Two of them came up from a town south of Houston, Texas. The girls, aged 4 and 8, rarely have a chance to see fireflies because they don't seem to have these amazing insects near their home. So, of course, we spent a few evenings chasing them and putting them into bottles to observe before letting them go. It was a real hoot to watch the girls chasing them down. At one point, the four-year-old, Billy, saw one of our solar lights come on and she darted over to it and tried to grab the firefly that she was sure must have landed on it.
So I have to ask myself--at what point do we stop enjoying these simple pleasures? Does it happen when we turn thirty? Forty? Is it possible to never lose the ability to enjoy simple things like chasing fireflies on a carefree summer evening?
I'm fifty-eight. But I have a lot to learn from my grandkids.
In honor of the beautiful summer evenings we've had lately here, today's awesome animal is the firefly! It's time to learn more about this amazing luminescent creature.
Some of you may live in areas that may not have fireflies, or perhaps you have other creatures (or fungi) that produce light. But here in the midwest US, fireflies can be seen by the hundreds on warm summer evenings.
So, what the heck is a Firefly?
Fireflies, often called lightning bugs, are neither flies nor bugs ("bug" is actually the name for insects in the order, Hemiptera, such as assassin bugs and stink bugs). Instead, they are beetles (beetles are in the order, Coleoptera). Astoundingly, there are 2,100 species of fireflies worldwide (although only some of them can light up). All of these species are in the family, Lampyridae. The family name, Lampyridae, comes from the Greek "lampein," which means to shine.
I find it interesting that, in the United States, there are distinct regions where people call these beetles fireflies and other regions where they are called lightning bugs. In fact, a study was done by Bert Vaux, a linguistics professor. He surveyed 10,000 people across the country regarding what they call these beetles. The resulting map is below. In the green area, people call them fireflies. In the blue area, they call them lightning bugs. And red is where they use both names.
What do people call these insects where you live?
Amazing facts about fireflies
Fireflies can light up (well, duh). It is a process called bioluminescence. You have to admit, this is a pretty cool superpower, right? Here is a very basic description of how it works. Fireflies have a substance in their abdomen called luciferin (yes, the name has the same Latin root as Lucifer). When luciferin mixes with calcium, oxygen, and adenosine triphosphate (ATP), a chemical reaction occurs that creates light. Even more amazing, this is the most efficient light we know of. In this chemical reaction, almost 100% of the resulting energy is released as light. In comparison, with an incandescent light bulb, only about 10% of the energy is released as light (the rest is released as heat).
The larvae of fireflies are wingless, and they typically live underground (although some live in water). The larvae can also light up, and in many areas, they are called glow worms. In some species, even the eggs glow! But the larvae and adults light up for a different purpose. The main reason adults light up is to attract mates. But the main reason the larvae light up is to warn predators away. You see, fireflies have horrible-tasting defense chemicals in their blood. Predators see the light and then avoid eating these insects. These yucky chemicals have the awesome name, lucibufagins. See the firefly larva below.
Check out this video of firefly larvae.
We used to think adult fireflies would light up mainly to warn predators to not eat them. But now we know the primary purpose (for the adults) is to attract mates. What's really cool is that each species has it's own specific light signals, so that they don't accidentally get attracted to the wrong species. The signal could be a steady glow, a specific flashing pattern, or even a specific color. The light may be green, yellow, or orange. There is even a species that lives in the Eastern US that glows blue.
In the larval form, fireflies are predators, feeding on worms, other insects, and snails. Once they become adults, some are predators while others feed on nectar or pollen. Some species, once they become adults, don't eat at all... they don't even have mouths! Obviously, these adults have one single purpose: to find a mate. Once they accomplish that, they soon die. I imagine not being able to eat gives them a real incentive to be quick about it!
Female fireflies of the genus Photuris have a nasty trick. They emit light in the specific pattern of the females of another species. This fools the males of the other species into eagerly approaching, thinking they are about to get lucky with a female of their own species, only to be gobbled up by the trickster. Females of the insect world (and spiders, for that matter) can be mean! The photo below is a female Photuris feeding on an unsuspecting male.
One of the most spectacular light shows from fireflies is that produced by those species that flash in sync with each other. Following a predictable pattern, they will all flash at once. This will be followed by several seconds of darkness, and then they will all flash again. Oddly, we aren't sure why some fireflies flash synchronously. It might be because this gives the males a better chance when the female can compare and pick out the best male light (the one that is brightest, maybe?).
Check out this video of synchronous fireflies.
Unfortunately, fireflies seem to be declining. One reason for this could be the increase in light pollution. Studies have shown (and it just seems logical to me) that artificial lights make it harder for fireflies to find their mates. Also, habitat destruction could be a factor. Fireflies aren't very resilient. When a field is paved, instead of moving to another field, the fireflies simply disappear forever. One additional factor might be that fireflies are collected in large numbers for their luciferase, which is useful in medical research.
So, the firefly deserves a place in the A.A.H.O.F. (Amazeballs Animal Hall of Fame).
FUN FACT: The word amazeballs may have come from Amazeballz, which is the name of a pastry shop that started in Plano, Texas (USA). They make miniature cake balls. During the last few years, I've heard people use this word to describe something that is beyond amazing, as in, "The new Star Wars movie is amazeballs!" So, amazeballs is another way to say awesome!
Cora and Billy catching fireflies - Stan C. Smith
Firefly #1 (Japanese firefly) -National Wildlife Federation
Firefly name map - NC State University Department of Statistics
Firefly larva - Till, via whatsthatbug.com
Predatory female firefly - AmazingLife.bio
Fireflies in the forest (Japan) - Miyu
Everyone needs a creative outlet. That's why I write.