Why Fireflies Glow and You Do Not

Introduction

The earth is quite amazing artistically and we are all witnesses of the amazing creatures existing around us. The echolocation abilities of dolphins and bats are one of the many extraordinary abilities of certain creatures that I happened to learn on this platform.

I am quite a curious person and I like to question basically everything and I guess that’s how we learn every day. I’ve always wondered why the cheetah (not the bot, which is quick in detecting similar contents anyway) had such an amazing pace and why anteaters had such lengthy tongues. This is just one of my many thoughts.

Growing up in the village at some point, I had first hand experience with certain flies that glowed at night. I was just a young boy who believed everything just had their properties and all we needed to do was admire them.

Growing up however, I began to see that there was basically a scientific explanation behind everything. I used to catch lots of fireflies as a boy, save them up in transparent bottles and witness how they collectively glowed. It was a joy to watch.

I also used to wish humans could somehow glow but I resorted to concluding that we were all created differently and thus, humans could never possess the glowing properties of fireflies. Looking at what has been achieved with Recombinant DNA technology, I could be wrong.

Before I go into the mechanism behind the firefly glow and why they actually glow. I’ll like to just discuss briefly about the firefly itself.

The FireFly: Probably The Only Thing That Lights Up My World At The Moment

The firefly, a member of the lampyridae family, is an insect that glows specifically at night. Made up of above 2,000 species, the firefly is known to be mostly nocturnal (I.e they are most active at night). A few exceptions exist however, in that diurnal (active during the day) fireflies have been recorded.

The fireflies are known to feed mainly on nectar and pollen although some have been observed to not even eat at all (I wonder how they survive). The fireflies in larvae stage of metamorphosis are known to feed on slugs and snails. The firefly can therefore be considered omnivorous in terms of mode of feeding as their larvae feed on animals and the adult firefly on plants.

It has been widely observed that in a species of firefly, only one sex possesses glowing properties and it always mostly the males. Some species don’t even glow at all anyway.

Females of most species of fireflies are without wings and are commonly referred to as glow worms. They can however be mistaken for the larvae form of the firefly but close observations have revealed that the glow worms actually have compound eyes in contrast with the larvae that possess simple eyes.

The larvae form of fireflies are known to undergo hibernation during winter and come forth as adult fireflies during spring. Little wonder why they are so abundant during springtime.

The FireFly Glow: Magic or Science ?

The fireflies are capable of glowing as we have all observed their twinkling at some point. The biochemical term used to describe this glow is bioluminiscence. Bioluminescence basically involves chemical reactions that lead to the production of light (cold light in this case).

Bioluminescence is actually seen more in deep sea animals and has also been observed in certain protozoans. The firefly is just another creature to share this property.

The production of light in fireflies is due to two major substances, luciferin, a reducing light emitting substance and luciferase, an enzyme that acts on luciferin. The light emission would not be possible however without the presence of oxygen which is tantamount to the process. ATP and Magnesium are also required for this process.

The biochemical logic involves the reaction of luciferin with ATP to produce pyrophosphate and luciferyl adenylate. This luciferyl adenylate loses a carboxyl (~COOH) group as carbon dioxide on addition of oxygen (this is known as oxidative decarboxylation) as well as its adenylate (Adenosine monophosphate) group leading to the formation of oxyluciferin with an emission of light. This Step is catalyzed by the enzyme luciferase. The oxyluciferin undergoes future reactions to yield luciferin to begin the whole process again. This is the mechanism behind bioluminescence in fireflies, some protozoans and even some deep sea animals

The million dollar question now is, if luciferin is the compound solely behind the light produced by most bioluminescent organisms, why do we have organisms producing different colours of light ? It is quite simple and plain. Luciferin varies structurally in different organisms and this tends to lead to the production of different colors of light by organisms on action of the enzyme; luciferase.

Another question that comes to mind is, if fireflies stay producing light, how do they stay alive ? as we can see in cases of light bulbs that light somehow leads to the release of heat and this is expected to occur in fireflies and also kill them too. Well, the light produced during bioluminescence is cold light and release very very little or no heat and this is basically how the firefly manages to stay alive.

Do fireflies Glow in an Attempt to act cool or there’s a biological reason(s) behind that ?

It’s easier to assume that fireflies glow for entertainment purposes but this is not even the reason. Maybe in an alternate universe, it could be. The firefly glow has been mainly due for biological purposes like mating, defence and identification.

The primary reason fireflies glow is mating. Just like boys tend to spray lots of colognes in an attempt to lure girls, the male fireflies of a certain species tend to glow in other to attract female counterparts of the same species. The rate of the glow as well as intensity of the glow is hugely determinant of the level of attraction of the male firefly. This simply means, the brighter and faster a male firefly glows, the quicker he gets laid. The female fireflies are very selective of the type of glows produced by male fireflies and often use this to identify males of similar species.

The female fireflies also glow but not for mating reasons. The female fireflies are very petty and use glows to attract males for the sake of consumption and no they are not inviting these males to dinner. These males are the dinner. In clearer words, female fireflies sometimes glow, attract males and eat them. Such a sad story.

Fireflies also glow for defence. Here, the glow doesn’t particularly act as a weapon but more of a reminder for predators. What are they being reminded of ? Well, fireflies can produce a substance that Is distasteful for predators rendering them unpalatable to predators. This substance is referred to as lucibufagins. The predators link this substance to the light produced by the firefly and do well to steer clear of the fireflies next time.

If the primary goal of bioluminescence in fireflies is mating, how do fireflies that do not produce light mate ?

Well, like I said earlier, not all species of fireflies glow. This leave the species without glowing properties with the task of figuring out how to mate. Well, they don’t seem to have a problem as most of them have figured another way to mate. This is through the production of pheromones. Pheromones are substances secreted by organisms that can actually influence the behavior of a receiving organism.

Fireflies can secrete pheromones therefore and influence the behavior of the opposite sex causing mating to occur. This is just as effective as the mechanism used by glowing fireflies.

Some special and evolutionary advanced fireflies however can both produce pheromones and glow all for the processes of mating. This has recently been observed and it is quite cool imo.

Summary

Fireflies can glow and we can not. I am a bit jealous and there’s really nothing that can be done. The biochemistry of bioluminescence has shown that the glowing ability of fireflies and other bioluminescent organisms is not magic but indeed has a chemical basis. I’ll like to leave you with this quote (by me).

since we (humans) all can’t glow like fireflies in a literal sense maybe we can someday shine like diamonds in the sky (at least Rihanna said so ) in a figurative sense.

Till Next Time. I hope you learned something today.

References

^{How and Why Do Fireflies Light Up the Sky. Retrieved on May 15th, 2018.
Why FireFlies Light Up. Retrieved on May 15th, 2018.
How Do FireFlies Glow. Retrieved on May 15th, 2018.
FireFly. Retrieved on May 15th, 2018.
FireFly; Insect. Retrieved on May 15th, 2018.
Bioluminiscence | Wikipedia. Retrieved on May 15th, 2018.
Bioluminiscence | Britanicca. Retrieved on May 15th, 2018.
Lehninger, A. L., Nelson, D. L., & Cox, M. M. (2000). Lehninger principles of biochemistry. New York: Worth Publishers. pp. 503.}

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