All you have to do is find yourself in nature on a warm summer night - and, quite possibly, you will be able to see a stunningly beautiful spectacle - dozens of small lanterns,...
All you have to do is find yourself in nature on a warm summer night and, quite possibly, you will be able to see a stunningly beautiful spectacle - dozens of small lanterns flickering in the darkness. It is fireflies that emit their extraordinary light. Many people 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 of tiny insects in a night field 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 glow effect. 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. This substance acts as a light reflector. Thanks to its presence, the glow of insects acquires a characteristic whitish tint.
Why do fireflies glow?
If scientists established the reasons for the glow of fireflies quite a long time ago, then the question of why insects need such a unique property remained open for quite a long time. Today, most researchers believe that In this 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, when 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, this difference may be indistinguishable to the human eye, but for small glowing 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 verify this if you are lucky enough to catch at least one firefly. Plant it in a jar and watch the beetle. Even if you put a hundred insects in there, the jar will not warm up at all. And all because fireflies are not able to emit warm light. This is exactly what they say about phenomena: it shines, but does not warm.
Who else glows in nature?
By the way, Not only fireflies have such an unusual natural gift. There are also other species of animals that are prone to releasing light energy. These include, for example, some types of jellyfish.
However, it is fireflies that have gained such wide fame due to their ability to glow in the dark. Interestingly, some types of fireflies can glow not only individually, but also in huge clusters. Most often, such phenomena are observed in hot countries located in southern latitudes. Seeing such beauty is real luck. At such moments, it seems that everything around is strewn with the radiance of iridescent lights, which either fade away or 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.
It is not surprising that 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? Scientists will probably find the answer to this in the coming years. interest Ask. In the meantime, we can only enjoy the beauty of these amazing animals and their fabulous shine.
Why do some fireflies glow synchronously?
The mating season of fireflies begins in June. At night you can see hundreds of blinking lights in the grass and foliage of trees. Why do fireflies glow?
Causes of bioluminescence
Glow occurs during the oxidation of certain substances found in the body of insects. This happens as follows:
- the firefly inhales;
- air passes through many tracheas to photogenic cells;
- oxygen molecules combine with calcium and adenosine triphosphate.
The insect's luminescent organs (lanterns) are located at the end of the abdomen. They are usually covered with a transparent cuticle. Lanterns consist of large photogenic cells entwined with threads of trachea and nerves. The glow would not be possible without light reflectors. They are cells with uric acid crystals.
Sometimes the ability to glow in the dark manifests itself not only in adult beetles, but also in their eggs and larvae. This is due to the abundance of the enzyme luciferase.
The insect emits 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 ranges from 5 to 10%, while this beetle converts up to 98% of the energy spent into light radiation. Some types of fireflies can regulate 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 reports its location. The frequency of the beetles' flickering varies, so females can easily recognize their partner. During the mating season, males of some tropical and North American species flash on and off in unison, to which flocks of females respond with a similar light display.
Why do the beetles blink at the same time?
About 2 thousand species of fireflies are known to science, but 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 synchronously. Usually a series of flashes alternates with a fairly long pause, after which the sequence is repeated. During a break, the female gives a response signal. It is worth noting that only 1% of the entire variety of firefly species have such synchronization.
The entomologists' experiment involved females of Photinus carolinus. Males have been replaced LED lamps, which reproduced the rhythm familiar to this type of firefly.
During the first experiment, all diodes blinked at the same frequency; during the second, the synchrony was slightly disrupted; during the next, the flashes appeared and died out at random. As a result, scientists found that in the first two situations, females responded to signals 80% of the time. During the third experiment, only 10% responded.
The researchers also found that a female surrounded by glowing males cannot identify her partner, whereas when communicating one-on-one with an individual of the opposite sex, this is not difficult for her. The coordinated rhythm of flashes reduces noise and helps insects find each other.
Fireflies are what make summer nights special. They usually hide in the grass and shine a mystical green light from there, hoping to attract the attention of the opposite sex. And they do it beautifully. Have you ever seen trees blinking, as if shrouded in electric garland? As always, behind the romance lies a complex chemical reaction.
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 pocket flashlight: the bottom layer is mirror-like and should reflect the light produced as a result of complex chemical reaction middle layer. The tissues of the middle layer consist of photocytes - cells capable of converting oxygen into light. The upper functional layer is represented by a transparent light-transmitting cuticle.Oxygen, which is necessary 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 processes necessary for existence take place in cells, including respiration. A nervous system regulates the operating modes of the flashlight.
There are plenty of organisms in nature that “carry light” - reefs, deep-sea fish, mollusks, jellyfish, etc. In both them and fireflies, the pigment luciferin is responsible for the glow, which is activated in luciferase with the help of the adenosine triphosphate molecule - ATP (a universal unit of cellular energy) and, when oxidized, creates a magical glow. This occurs during the separation of carbon dioxide molecules, when the luciferin molecules come 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, maybe the soul. Photons contain neither infrared nor ultraviolet rays. But “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 a method of communication between the sexes - a very romantic and beautiful one. Males of North American and tropical species, for example, organize 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 females of the Photuris species, 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 the act of cannibalism occurs without good reason.
Female representatives give a special signal indicating that they are ready for fertilization. This is how 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 - this is something scientists cannot explain. But it can be assumed that in this way they convey a signal to predators that they are inedible.
In Eurasia, the most common species is called the “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 Could Teach Us
In addition to cultivating a sense of beauty in people, fireflies can boast of 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 its efficiency by 55%!Firefly symbolism
According to some peoples, fireflies are the souls of the dead who cannot find their way. Well, how else can you explain this magic? In Feng Shui philosophy, the firefly is positioned as a symbol of the rebirth of souls. The extraordinary radiance of the insect gives it an almost sacred character.But the Japanese have the greatest number of traditions and the deepest symbolism of fireflies. As befits a warm, humid climate, they glow with much more enthusiasm than their pale cousins from mid-latitudes. Therefore, the period of their mating is a grandiose light show. Japan even celebrates the Firefly festival - the Hotaru Festival.
People have used fireflies for the most different needs- as a decoration in the hair, as a tool for creating a romantic atmosphere, as a lighting device, as an assistant 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 monitoring the quality of food products.
The firefly population 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
The flying, flickering lights of fireflies are a real mystical attraction in summer time. But how much do we know about what fireflies are? Here are some facts about them.
1. What are fireflies?
Fireflies are nocturnal insects - they lead an active lifestyle at night. They are members of the winged beetle family Lampyridae (which means "to shine" in Greek). The name "firefly" is a little misleading because of the more than 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 most popular species due to their ability to glow. Most bioluminescent creatures live in the ocean—people have little contact with them. Their light is created through a chemical reaction in which oxygen combines with calcium, adenosine triphosphate (ATP) and luciferin using the enzyme luciferase. Fireflies use their bioluminescence probably to ward off predators.
3. Not all fireflies have "fire"
fireflies, most of their types simply do not 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 obtain the chemical luciferase is to extract it from fireflies. Eventually, scientists figured out how to create synthetic luciferases. But some people still collect enzyme from "flying lanterns." Luciferase is used in scientific research for safety testing food products and certain forensic procedures.
5. Fireflies are energy efficient
Firefly lights are the most efficient energy sources in the world. One hundred percent of the energy they create is emitted through light. By comparison, an incandescent light bulb emits only 10 percent of its energy as light, while fluorescent lamps emit 90 percent of their energy as light.
6. Their light show is mating acts.
Most flying male fireflies are looking for a mate. Each species has a specific light pattern that they use to communicate with each other. After the female sees the male and responds to his affection, she responds to him with the same light pattern. Usually females sit on plants, waiting for a 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 become more visible. If a group of fireflies blink in a single pattern, they are likely doing so to attract the attention of females. The only firefly species in America that blinks synchronously is Photinus carolinus. They live in the Great Smoky National Park, where the park service hosts an evening light show for visitors.
8. Not all fireflies shine the same way.
Each species has its own specific color of light. Some produce a blue or Green colour, while others glow orange or yellow.
9. They taste disgusting
Unlike cicadas, fireflies cannot be cooked into grilled bugs. If you try to eat 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 - they move away from meat. Scientists believe that adult fireflies live off nectar and pollen, or do not eat at all. But others, fireflies such as Photuris, may enjoy eating their own species. Photuris females often eat males of other genera. They attract unsuspecting beetles by mimicking their light patterns.
11. Their numbers are decreasing
There are several reasons why firefly populations are declining, including climate change and habitat destruction. When a firefly's habitat is disturbed due to road 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 have no clear 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 that has the amazing ability to emit light.
Despite the fact that 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 to a fairy tale of fireflies.
Habitat
Firefly beetle lives in the territory North America, Europe and Asia. It can be found in tropical and deciduous forests, meadows, clearings and swamps.
Appearance
Externally, the firefly insect looks very modest, even inconspicuous. The body is elongated and narrow, the head is very small, and the antennae are short. The size of the firefly insect is small - on average from 1 to 2 centimeters. The body color is brown, dark gray or black.
Many species of beetles have distinct differences between male and female. Male insect fireflies resemble cockroaches in appearance and can fly, but do not glow.
The female looks very similar to a larva or worm; she has no 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 svelorgan of the firefly insect is located in the rear part of the abdomen. It is a collection of light cells - photocytes, through which multiple tracheas 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. This may be a continuous glow, blinking, pulsating or flashing. Thus, the glow-in-the-dark bugs resemble a New Year's garland.
Lifestyle
Fireflies are not collective insects, however, they often form large clusters. During the day, fireflies rest, sitting on the ground or on plant stems, and at night they begin an active life.
Different types of fireflies differ in their feeding patterns. Harmless herbivorous insects, 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 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 if disturbed.
Beetle larvae overwinter in the bark of trees. In the spring they come out of hiding, feed heavily, and then pupate. After 2 - 3 weeks, adult fireflies emerge from the cocoon.
- The brightest firefly beetle lives in the American tropics.
- It reaches 4–5 centimeters in length, and not only its abdomen glows, but also its chest.
- In terms of the brightness of the light emitted, this bug is 150 times greater than its European relative, the common firefly.
- Fireflies were used by residents of tropical villages as lamps. They were placed in small cages and used such primitive lanterns to illuminate their homes.
- Every year at the beginning of summer, the Firefly Festival is held in Japan. At 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 firefly. It received this 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 the grass and shine a flashlight at the place where the light is burning, you can see an inconspicuous worm-like segmented insect, the end of its abdomen glows green. This is what a female looks like firefly (Lampyris noctiluca). People call him Ivanov the worm, Ivanovo worm because of the belief that it appears for the first time of the year on the night of Ivan Kupala. Only females waiting for males on the ground or vegetation are capable of emitting bright light; males practically do not emit light. The male firefly looks like an ordinary normal beetle with hard wing covers, while the female in adulthood remains similar to a larva and has no wings at all. Light is used to attract a male. A special organ that emits light is located on the last segments of the abdomen and has a very interesting structure: there is a lower layer of cells. containing a large number of urea crystals, and acts as a mirror reflecting light. The luminiferous layer itself is penetrated by tracheas (for oxygen access) and nerves. Light is produced by the oxidation of a special substance, luciferin, with the participation of ATP. For fireflies, this is a very efficient process, occurring with almost 100% efficiency, all the energy goes into light, with virtually no heat generated. And now a little more detail about all this.
Common 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 theirs appearance They 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 photocytic cells intertwined with tracheas and nerves. Each such cell is filled with “fuel”, which is the substance luciferin. When a firefly breathes, air enters the luminous organ through the trachea, where luciferin is oxidized under the influence of oxygen. 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 are also not far behind in this regard. 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 even care about saving money, because the productivity of their luminous organs would be the envy of any technician. Coefficient useful action in fireflies it reaches a fantastic 98%! This means that only 2% of energy is wasted, and in human creations (cars, electrical appliances) between 60 and 96% of energy is wasted.
Several chemical compounds are involved in the glow reaction. One of them, resistant to heat and present in small quantities, is luciferin. Another substance is the enzyme luciferase. Also, for the glow reaction, adenosine triphosphoric acid (ATP) is also required. Luciferase is a protein rich in sulfhydryl groups.
Light is produced by the oxidation of luciferin. Without luciferase, the rate of reaction between luciferin and oxygen is extremely low; catalyzing luciferase significantly increases its rate. ATP is required as a cofactor.
Light arises when oxyluciferin transitions from an excited state to a ground state. In this case, oxyluciferin is associated with an enzyme molecule and, depending on the hydrophobicity of the microenvironment of the excited oxyluciferin, the emitted light varies various types fireflies from yellow-green (with a more hydrophobic microenvironment) to red (with a less hydrophobic). The fact is that in a more polar microenvironment, some of the energy is dissipated. Luciferases from various fireflies generate bioluminescence with maxima from 548 to 620 nm. In general, the energy efficiency of the reaction is very high: almost all of the reaction energy is transformed into light without emitting heat.
All beetles contain the same luciferin. Luciferase, on the contrary, has different types are different. It follows that the change in the color of the glow depends on the structure of the enzyme. As studies have shown, temperature and pH of the environment 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 glow is emitted by photogenic granules located in the cytoplasm. When examining fresh sections of photogenic cells under ultraviolet rays, these granules can be detected by their other property - fluorescence - depending on the presence of luciferin.
The quantum yield of the reaction, compared to classical examples of luminescence, is unusually high, approaching unity. In other words, for each luciferin molecule participating in the reaction, one quantum of light is emitted.
Fireflies are predators, feeding on insects and shellfish. Firefly larvae lead a wandering life, like ground beetle larvae. The larvae feed on small invertebrates, mainly terrestrial mollusks, in whose shells they often hide themselves.
Adult beetles do not feed and die soon after mating and laying eggs. The female lays eggs on leaves or on the ground. Soon, black larvae with yellow speckles emerge from them. They eat a lot and grow quickly and, by the way, also glow. At the beginning of autumn, while it is still warm, they climb under the bark of trees, where they spend the entire winter. In the spring they come out of hiding, fatten for several days, and then pupate. After two weeks, young fireflies appear.
Looking at the bright flickering of fireflies, since ancient times people have wondered why not use them for useful purposes. The Indians attached them to moccasins to illuminate paths and scare away snakes. The first settlers to South America used these bugs as lighting for their huts. In some settlements this tradition has been preserved to this day.
