One has only to be in nature on a warm summer night - and, quite possibly, you will be able to see a spectacle of stunning beauty - dozens of small lanterns,...
One has only to be in nature on a warm summer night - and, quite possibly, you will be able to see a spectacle of stunning beauty - dozens of small lanterns flickering in the dark. These fireflies emit their unusual light. Many have seen these amazing creatures, but not everyone knows why fireflies tend to glow. Let's try to understand the reasons for this unique natural phenomenon.
Of course, the glow in the night field of tiny insects is a fabulous sight that inspires and amazes the imagination. Many believe that this process is akin to a real miracle. In fact, this phenomenon has a completely logical scientific explanation. It's all about the special structure of the firefly's body. The fact is that this little beetle has special cells on its abdomen - photocytes. They are what lead to the effect of the glow. Each photocyte contains two chemical compounds, luciferase and luciferin. Combining in the body of a firefly, these substances form a certain chemical reaction that occurs with the release of light.
Under the layer of photocytes, which is located on the surface of the body, there is a layer of other cells filled with substance white color. This substance acts as a reflector of light. Due to its presence, the glow of insects acquires a characteristic whitish hue.
Why do fireflies glow?
If scientists established the reasons for the glow of fireflies a long time ago, then the question of why insects need such a unique property remained open for a long time. Today, most researchers believe that in such an unusual way, beetles attract individuals of the opposite sex. Moreover, different types of fireflies emit light of different frequencies. This is necessary so that each male, attracting a female, pays attention only to representatives of his own species. In total, about two thousand species are known in the world, and each of them emits its own special light. Of course, for the human eye, this difference may be indistinguishable, but for small luminous beetles, it is of great importance.
Few people know that the light emitted by these unique insects is not warm, but cold. Unlike, for example, sunlight, this radiance does not warm at all. You can be convinced of this if you are lucky enough to catch at least one firefly. Put it in a jar and watch the beetle. Even if you put a whole hundred insects in there, the jar will not get warm at all. And all because fireflies are not able to emit warm light. It is about such phenomena that they say: it shines, but does not heat.
Who else glows in nature?
By the way, not only fireflies have such an unusual natural gift. There are other animal species that are prone to the release of light energy. These include, for example, some types of jellyfish.
However, it was fireflies that received such widespread fame due to their ability to glow in the dark. Interestingly, some species of fireflies can glow not only one by one, but also in huge clusters. Most often, such phenomena are observed in hot countries located in southern latitudes. To see such beauty is real luck. At such moments, it seems that everything around is strewn with the radiance of iridescent lights, which then fade away, then light up again. In some countries, clusters of fireflies glow so often and on such a large scale that these insects are even used as free lighting at night.
Not surprisingly, many modern scientists are interested in the phenomenal properties of fireflies. Many researchers have a question: is it possible to somehow use the energy of these insects? Probably, in the coming years, scientists will find the answer to this interest Ask. In the meantime, we can only enjoy the beauty of these amazing animals and their fabulous radiance.
Why do some fireflies glow in sync?
In June, the mating season of fireflies begins. At night, you can watch hundreds of flashing lights in the grass and foliage of trees. Why do fireflies glow?
Causes of bioluminescence
Glow occurs when certain substances in the body of insects are oxidized. It happens like this:
- the firefly inhales;
- air passes through many windpipes to photogenic cells;
- oxygen molecules combine with calcium and adenosine triphosphate.
The insect's luminous organs (lanterns) are located at the end of the belly. They are usually covered with a transparent cuticle. Lanterns consist of large photogenic cells, braided with threads of trachea and nerves. The glow would be impossible without light reflectors. They are cells with uric acid crystals.
Sometimes the ability to glow in the dark is manifested not only in adult beetles, but also in their eggs and larvae. This is due to the abundance of the enzyme luciferase.
insect radiates cold light. It is in the visible green-yellow part of the spectrum in the wavelength range of 500-600 nm. The efficiency of a conventional incandescent lamp is from 5 to 10%, while this beetle converts up to 98% of the energy spent into light radiation. Some types of fireflies can adjust the intensity of the glow and the frequency of blinking.
Bioluminescence is a means of communication between males and females. By blinking, the luminous insect announces its location. The flicker frequency of beetles varies, so females can easily recognize their partner. During the mating season, males of some tropical and North American species flash and fade synchronously, to which flocks of females respond with a similar light presentation.
Why are the beetles blinking at the same time?
About 2 thousand species of fireflies are known to science, however, insects that have developed the ability to coordinate outbreaks in the process of evolution live only in a few places on the planet, namely:
- in the Great Smoky Mountains National Park in the USA;
- in Malaysia;
- in Thailand;
- in the Philippines.
Scientists from the University of Connecticut conducted several experiments with insects of the species Photinus carolinus to find out why fireflies glow in sync. Usually a series of flashes alternates with a rather long pause, after which the sequence repeats. During the break, the female gives a response signal. It is worth noting that only 1% of the entire set of firefly species has such synchronization.
In the experiment of entomologists, females of Photinus carolinus were involved. The males were replaced LED lamps, which reproduced the rhythm familiar to this species of fireflies.
During the first experiment, all diodes flashed with the same frequency, during the second experiment, the synchronism was slightly disturbed, during the next experiment, the flashes appeared and faded out of order. As a result, scientists found that in the first two situations, females responded to signals in 80% of cases. During the third experiment, the reaction followed only 10%.
The researchers also found that a female surrounded by luminous males cannot identify her partner, while when communicating with an individual of the opposite sex one on one, this is not difficult for her. The coordinated rhythm of the flashes reduces the noise and helps the insects find each other.
Fireflies are what make summer nights so special. Usually they hide in the grass and shine from there with a mystical green light, hoping to attract the attention of the opposite sex. And they do it beautifully. Have you ever seen twinkling trees as if enveloped in electric garland? As always, there is a complex chemical reaction behind romance.
How fireflies glow
Fireflies glow due to a unique organ in their body - a photophore. It is located in the tail of the abdomen and has complex structure, representing three functional layers. For clarity, let's imagine an ordinary flashlight: the bottom layer is a mirror and should reflect the light produced as a result of a complex chemical reaction middle layer. The tissues of the middle layer are composed of photocytes - cells capable of converting oxygen into light. The upper functional layer is represented by a transparent light-transmitting cuticle.The oxygen required in large quantities to create the glow of a firefly is displaced from cellular mitochondria by replacing it with nitric oxide. Insects do not have lungs, so all the processes necessary for existence take place in the cells, including respiration. A nervous system adjusts the operating modes of the “flashlight”.
In nature, there are plenty of organisms that “carry light” - reefs, deep-sea fish, mollusks, jellyfish, etc. Both in them and in fireflies, the pigment luciferin is responsible for the glow, which is activated in luciferase with the help of an adenosine triphosphate molecule - ATP (the universal unit of cellular energy) and, oxidized, creates a magical glow. This happens during the separation of carbon dioxide molecules, when the luciferin molecules go out of their excited state, releasing light energy, thereby the firefly begins to glow in the dark.
The mysterious and cold glow of fireflies really does not warm at all - well, except perhaps the soul. Photons contain neither infrared nor ultraviolet rays. But on the other hand, “lighting” takes about 98% of the energy expended, unlike ordinary electric lamp, whose efficiency is only 10%, and whose energy is partially spent on useless heat.
Why do fireflies glow
Why do fireflies glow, why is it necessary? The fact is that bioluminescence can and should be attributed to the way of communication between the sexes - very romantic and beautiful. Males of North American and tropical species, for example, arrange a real pre-wedding flash mob. Insects sit on a tree and blink randomly at dusk. After a while, they catch a single rhythm, synchronizing into a single lighting fixture- and the tree seems to be decorated with a living garland.
Female fireflies, by the way, are not particularly beautiful - they, unlike males, do not have wings, but they also luminesce synchronously in response to the guys from the tree. However, women are cunning - especially the female Photuris, who pretend to be another species - Photinus. Subsequently, the deceived males of the Photinus species are eaten, but the females gain confidence in the future, because the bodies of their victims contain a special enzyme that repels birds and spiders. Sometimes an act of cannibalism occurs without good reason.
Female representatives give a special signal indicating that they are ready for fertilization. So the male understands where to fly. In general, the brighter it glows, the more female attention it attracts.
In addition, their larvae, pupae and eggs glow - scientists cannot explain this. But it can be assumed that in this way they transmit a signal to predators that they are inedible.
In Eurasia, the most common species is called "Ivan's worm". It is believed that it is on the night of Ivan Kupala that these insects become more active.
An interesting fact is that out of 2000 species, only a few fireflies glow, the rest mainly function only during the day.
What Fireflies Can Teach Us
In addition to instilling a sense of beauty in people, fireflies boast the efficiency of converting their energy into light. Recently, researchers studying the body surface of fireflies noted its scaly structure, reminiscent of roof tiles. Using nanotechnology, they tried to create a similar structure on the surface of the LED. And this increased the efficiency of his work by 55%!Symbolism of the firefly
According to the beliefs of some peoples, firefly beetles are the souls of the dead who cannot find their way. Well, how else to explain this magic? In Feng Shui philosophy, the firefly is positioned as a symbol of the rebirth of souls. The unusual radiance of the insect gives it an almost sacred character.But the greatest number of traditions and the deepest symbolism of fireflies are bestowed by the Japanese. As befits a warm and humid climate, they glow with much more enthusiasm than their pale relatives from the middle latitudes. Therefore, the period of their mating is a grandiose light show. Japan even celebrates the Firefly Festival - the Hotaru Festival.
People used firefly beetles for the most different needs- as an ornament in the hair, as a tool for creating a romantic atmosphere, as a lighting fixture, as helpers in the fight against evil spirits. Today, synthetic luciferase, which was originally extracted from living insects, is used in forensic medicine, as well as for food quality control.
The population of fireflies has fallen sharply, and this is due to pollution and destruction of their habitats. The fact is that they do not migrate from these places, but simply disappear.
Video about why fireflies glow
Fireflies - a luminous miracle of nature
Flying, flickering lights of fireflies - a real mystical attraction in summertime. But how much do we know about what fireflies are. Here are some facts about them.
1. What are firefly beetles
Fireflies are nocturnal insects - they are active at night. They are members of the Lampyridae family of winged beetles (which means "shine" in Greek). The name "firefly" is a little misleading because of the over 2,000 species of fireflies, only a few of these species have the ability to light up.
2. There are other types of glowing species besides fireflies.
Fireflies are probably one of the more popular species because of their ability to glow. Most bioluminescent creatures live in the ocean - humans have little contact with them. Their light is created by a chemical reaction that combines oxygen with calcium, adenosine triphosphate (ATP) and luciferin via the enzyme luciferase. Fireflies use their bioluminescence, presumably to scare away predators.
3. Not all fireflies have "fire"
fireflies, most of their kinds, just don't burn. Non-bioluminescent fireflies, which do not produce light, are generally not nocturnal bugs—they are most active during the day.
4. Scientists discovered luciferases thanks to fireflies
The only way to get the chemical luciferase is to extract it from a firefly. Eventually, scientists figured out how to make synthetic luciferases. But some people still collect the enzyme from flying lanterns. Luciferase is used in research for safety testing food products and some forensic procedures.
5. Fireflies are energy efficient
Firefly lights are the most efficient sources of energy in the world. One hundred percent of the energy they create is radiated through light. By comparison, an incandescent lamp emits only 10 percent of its energy as light, while fluorescent lamps emit 90% of their energy as light.
6. Their light show is mating.
Most flying male fireflies are looking for a mate. Each species has a specific pattern of light that they use to communicate with each other. After the female sees the male and responds to his love, she reacts to him with the same light pattern. Usually females sit on plants, waiting for the male.
7. Some species have the ability to synchronize their blinking.
Scientists aren't sure why fireflies do this, but some theories suggest that fireflies do it to make themselves more visible. If a group of fireflies blink in a single pattern, then most likely they are doing this to attract the attention of females. The only firefly species in America that blinks in sync is Photin carolinus. They live in the US Great Smoky National Park, where the park service organizes evening light show hours for visitors.
8. Not all fireflies shine the same.
Each species has its own specific color of light. Some produce a glow of blue or Green colour while others glow orange or yellow.
9. They taste disgusting
Unlike cicadas, fireflies cannot be cooked in grilled beetles. If you try to eat a firefly, it will taste bitter. The bugs can even be toxic. When fireflies are attacked, they shed drops of blood. Blood contains chemical substances, which create a bitter taste and poison. Most animals know this and avoid chewing fireflies.
10. Fireflies sometimes practice cannibalism
When fireflies are still in their larval stage, they are ready to feast on snails. Usually, when they mature, they become vegetarians - moving away from meat. Scientists believe that adult fireflies live off nectar and pollen, or don't eat at all. But others, fireflies like Photuris, may enjoy eating their own species. Photuris females often eat males of other genera. They attract unsuspecting beetles by mimicking their light pattern.
11. Their numbers are dwindling.
There are several reasons why the firefly population is declining, including climate change and habitat destruction. When a firefly's habitat is disturbed due to road construction or other construction, they do not migrate to a new location, but simply disappear.
12. Enjoy the firefly light show while you can
Researchers know little about fireflies and don't give a definitive answer as to why they are disappearing. Enjoy the light show while this insect still exists in nature. Perhaps the generations of people who will come after us will not be given such an opportunity to see these beetles with their amazing mystical glow.
The firefly insect is a large family of beetles with an amazing ability to emit light.
Despite the fact that insect fireflies do not bring practically any benefit to humans, the attitude towards these unusual insects has always been positive.
Watching the simultaneous flickering of many lights in the night forest, you can be transported for a while into the fairy tale of fireflies.
Habitat
The firefly beetle lives in the territory North America, Europe and Asia. It can be found in tropical and deciduous forests, meadows, glades and swamps.
Appearance
Outwardly, the firefly insect looks very modest, even nondescript. The body is elongated and narrow, the head is very small, the antennae are short. The size of the insect firefly is small - on average from 1 to 2 centimeters. The body color is brown, dark gray or black.
In many species of beetles, differences between male and female are pronounced. Male firefly insects resemble cockroaches in appearance, can fly, but do not glow.
The female looks very similar to a larva or a worm, she does not have wings, so she leads a sedentary lifestyle. But the female knows how to glow, which attracts representatives of the opposite sex.
Why does it glow
The luminous swell organ of the insect firefly is located in the back of the abdomen. It is an accumulation of light cells - photocytes, through which multiple tracheae and nerves pass.
Each such cell contains the substance luciferin. During breathing, oxygen enters the luminous organ through the trachea, under the influence of which luciferin is oxidized, releasing energy in the form of light.
Due to the fact that nerve endings pass through the light cells, the firefly insect can independently regulate the intensity and mode of the glow. It can be a continuous glow, blinking, pulsing or flashes. Thus, bugs glowing in the dark resemble a New Year's garland.
Lifestyle
Fireflies are not collective insects, however, they often form large clusters. During the day, fireflies insects rest, sitting on the ground or on plant stalks, and at night they begin an active life.
Different types of fireflies differ in the nature of their diet. Harmless herbivorous insect fireflies feed on pollen and nectar.
Predatory individuals attack spiders, centipedes and snails. There are even species that at the adult stage do not feed at all, moreover, they do not have a mouth..
Lifespan
The female beetle lays its eggs on a bed of leaves. After some time, black-and-yellow larvae emerge from the eggs. They have an excellent appetite, in addition, the firefly insect glows when disturbed.
Beetle larvae overwinter in the bark of trees. In the spring they emerge from the shelter, feed intensively, then pupate. After 2 - 3 weeks, adult fireflies emerge from the cocoon.
- The brightest firefly beetle lives in the American tropics.
- In length, it reaches 4 - 5 centimeters, and not only the abdomen, but also the chest glows in it.
- In terms of the brightness of the emitted light, this bug is 150 times superior to its European relative, the common firefly.
- Fireflies were used by the inhabitants of tropical villages as lamps. They were placed in small cages and with the help of such primitive lanterns they illuminated their dwellings.
- Every year at the beginning of summer, the Firefly Festival is held in Japan. With the onset of dusk, spectators gather in the garden near the temple and watch the fabulously beautiful flight of many luminous bugs.
- The most common species in Europe is the common firefly, which is popularly called the Ivan worm. It received such a name because of the belief that the firefly insect begins to glow on the night of Ivan Kupala.
On warm nights in late June - early July, walking along the edge of the forest, you can see bright green lights in the grass, as if someone had lit small green LEDs. Summer nights are short, you can watch this spectacle for just a couple of hours. But if you rake up the grass and shine a flashlight on the place where the light burns, you can see a nondescript worm-like segmented insect, in which the end of the abdomen glows green. This is what a female looks like firefly (Lampyris noctiluca). People call him Ivanov worm, Ivanovo worm because of the belief that for the first time in a year it appears on the night of Ivan Kupala. Only females waiting for males on the ground or vegetation can emit bright light; males practically do not emit light. The male firefly looks like an ordinary normal beetle with hard elytra, while the female in adulthood remains similar to a larva, and does not have wings at all. Light is used to attract the male. A special organ that emits a glow is located on the last segments of the abdomen and is very interesting: there is a lower layer of cells. containing a large number of urea crystals, and acts as a mirror that reflects light. The luminiferous layer itself is permeated with tracheae (for oxygen access) and nerves. Light is formed by the oxidation of a special substance - luciferin, with the participation of ATP. In fireflies, this is a very efficient process, occurring at almost 100% efficiency, all the energy goes into the light, with little or no heat. And now a little more about all this.
firefly (Lampyris noctiluca) is a member of the firefly family ( Lampyridae) order of beetles (coleoptera, Coleoptera). The males of these beetles have a cigar-shaped body, up to 15 mm long, and a rather large head with large hemispherical eyes. They fly well. The females are their own appearance resemble larvae, have a worm-like body up to 18 mm long, and are wingless. Fireflies can be seen on forest edges, damp glades, on the banks of forest lakes and streams.
The main ones in every sense of the word are their luminous organs. In most fireflies, they are located in the back of the abdomen, resembling a large flashlight. These organs are arranged according to the principle of a lighthouse. They have a kind of "lamp" - a group of photocyte cells, braided with tracheae and nerves. Each such cell is filled with "fuel", which is the substance luciferin. When the firefly breathes, air through the trachea enters the luminous organ, where, under the influence of oxygen, luciferin is oxidized. During a chemical reaction, energy is released in the form of light. A real lighthouse always emits light in the right direction - towards the sea. Fireflies in this regard, too, are not far behind. Their photocytes are surrounded by cells filled with uric acid crystals. They perform the function of a reflector (mirror-reflector) and allow you not to waste valuable energy in vain. However, these insects might not care about economy, because any technician can envy the performance of their luminous organs. Coefficient useful action in fireflies it reaches a fantastic 98%! This means that only 2% of energy is wasted, and in the creations of human hands (cars, electrical appliances) from 60 to 96% of energy is wasted.
Several chemical compounds are involved in the glow reaction. One of them, resistant to heat and present in a small amount - luciferin. Another substance is the enzyme luciferase. Adenosine triphosphoric acid (ATP) is also needed for the glow reaction. Luciferase is a protein rich in sulfhydryl groups.
Light is produced by the oxidation of luciferin. Without luciferase, the rate of the reaction between luciferin and oxygen is extremely low, catalyzed by luciferase greatly increases its rate. ATP is required as a cofactor.
Light arises when oxyluciferin passes from the excited state to the ground state. In this case, oxyluciferin is bound to the enzyme molecule and, depending on the hydrophobicity of the microenvironment of the excited oxyluciferin, the emitted light varies in various kinds fireflies from yellow-green (with a more hydrophobic microenvironment) to red (with a less hydrophobic one). The fact is that with a more polar microenvironment, part of the energy is dissipated. Luciferases from various fireflies generate bioluminescence with peaks from 548 to 620 nm. In general, the energy efficiency of the reaction is very high: almost all the energy of the reaction is transformed into light without emitting heat.
All beetles contain the same luciferin. Luciferases, on the other hand, different types different. It follows that the change in the color of the luminescence depends on the structure of the enzyme. Studies have shown that the temperature and pH of the medium have a significant effect on the color of the glow. At the microscopic level, luminescence is characteristic only of the cytoplasm of cells, while the nucleus remains dark. The luminescence is emitted by photogenic granules located in the cytoplasm. In the study of fresh sections of photogenic cells in ultraviolet rays, these granules can be detected by their other property - fluorescence - depending on the presence of luciferin.
The quantum yield of the reaction is unusually high compared to classical examples of luminescence, approaching unity. In other words, for each luciferin molecule involved in the reaction, one light quantum is emitted.
Fireflies are carnivores, feeding on insects and mollusks. Firefly larvae lead a wandering life, like ground beetle larvae. The larvae feed on small invertebrates, mainly terrestrial mollusks, in the shells of which they often hide themselves.
Adult beetles do not feed and die shortly after mating and oviposition. The female lays eggs on leaves or on the ground. Soon, black larvae with yellow speckles appear from them. They eat a lot and grow quickly and, by the way, also glow. In early autumn, while it is still warm, they climb under the bark of trees, where they spend the whole winter. In the spring, they emerge from the shelter, feed for several days, and then pupate. Two weeks later, young fireflies appear.
Looking at the bright flickering of fireflies, since ancient times, people have been wondering why not use them for useful purposes. The Indians attached them to moccasins to illuminate the paths and scare away snakes. The first settlers in South America used these bugs as lighting for their huts. In some settlements, this tradition has been preserved to this day.
