Living radiance
“... at first only two or three green dots were blinking there, gliding smoothly among the trees.
But gradually there were more of them, and now the whole grove is illuminated by a fantastic green glow.
Never before have we seen such a huge cluster of fireflies.
They ran like a cloud among the trees, crawled over the grass, bushes and trunks ...
Then sparkling streams of fireflies floated over the bay ... "
J. Darrell. "My family and other animals"
Probably everyone has heard about fireflies. Many have seen them. But what do we know about the biology of these amazing insects?
Fireflies, or fireflies, are members of a separate family Lampyridae in the detachment of beetles. In total, there are about 2000 species, and they are distributed almost all over the world. The sizes of different types of fireflies range from 4 to 20 mm. The males of these beetles have a cigar-shaped body and a rather large head with large hemispherical eyes and short antennae, as well as very reliable and strong wings. But female fireflies are usually wingless, soft-bodied and resemble larvae in their appearance. True, in Australia there are species in which wings are developed in both males and females.
All types of fireflies have the amazing ability to emit soft phosphorescent light in the dark. Their organ of luminescence is photophore- most often located at the end of the abdomen and consists of three layers. The lower layer acts as a reflector - the cytoplasm of its cells is filled with microscopic crystals of uric acid that reflect light. The top layer is represented by a transparent, light-transmitting cuticle - in a word, everything is like in an ordinary lantern. The photogenic cells themselves, which produce light, are located in the middle layer of the photophore. They are densely entwined with trachea, through which air is supplied with the oxygen necessary for the reaction, and contain a huge number of mitochondria. Mitochondria produce the energy necessary for the oxidation of a special substance, luciferin, with the participation of a corresponding enzyme, luciferase. The visible result of this reaction is bioluminescence - luminescence.
The efficiency of firefly flashlights is unusually high. If in an ordinary light bulb only 5% of the energy is converted into visible light (and the rest is dissipated in the form of heat), then from 87 to 98% of the energy of fireflies goes into light rays!
The light emitted by these insects belongs to a rather narrow yellow-green region of the spectrum and has a wavelength of 500-650 nm. There are no ultraviolet and infrared rays in the bioluminescent light of fireflies.
The glowing process is under nervous control. Many species are capable of increasing and decreasing the intensity of light at will, as well as emitting intermittent light.
Both males and females of fireflies have a luminous organ. Moreover, the larvae, pupae, and even the eggs laid by these beetles glow, although much weaker.
The light emitted by many tropical firefly species is very bright. The first Europeans to settle in Brazil, in the absence of candles, lit their homes with fireflies. They also filled the icon lamps in front of the icons. Indians, traveling through the jungle at night, still tie large fireflies to their toes. Their light not only helps to see the road, but possibly scares away snakes.
Entomologist Evelyn Chisman wrote in 1932 that some eccentric ladies in South America and the West Indies, where especially large fireflies are found, adorned their hair and dresses with these insects before the evening holidays, and their living ornaments sparkled like diamonds.
You and I cannot admire the glow of bright tropical species, but fireflies also live in our country.
Our most common big firefly(Lampyris noctiluca) is also known as “ ivanov worm ". This name was given to the female of this species, which has an elongated wingless body. It is her rather bright flashlight that we usually notice in the evenings. Males of Ivan's worm are small (about 1 cm) brown beetles with well-developed wings. They also have glowing organs, but you can usually notice them only by picking up the insect.
In the book by Gerald Durrell, the lines from which are taken as an epigraph to our article, it is most likely mentioned flying firefly -Luciola Mingrelik beetleLuciola mingrelica, found not only in Greece, but also on the Black Sea coast (including in the Novorossiysk region), and often arranges similar fantastic performances there.
And in Primorye you can find a rare and little-studied firefly pyrocelium(Pyrocaelia rufa). Both males and females of this species glow actively on dark August nights.
In Japan live Luciola parva and Luciola vitticollis.
It is believed that the bioluminescence of fireflies is a means of inter-sex communication: partners let each other know about their location with light signals. And if our fireflies glow with a constant light, then many tropical and North American forms flash their lanterns, and in a certain rhythm. Some species perform real serenades for their partners, moreover choral ones, flashing and fading in unison with the whole flock gathered on one tree.
And the beetles located on the neighboring tree also flare up in concert, but not in time with the fireflies sitting on the first tree. Also, in their own rhythm, bugs glow on other trees. Eyewitnesses say that this spectacle is so bright and beautiful that it overshadows the illumination of large cities.
Hour after hour, weeks and even months, the bugs blink on their trees in the same rhythm. Neither wind nor heavy rain can change the intensity and frequency of the flashes. Only the bright light of the moon can dim these unique natural lanterns for a while.
If you shine a bright lamp on the tree, you can make the flashes out of sync. But when the outside light goes out, the fireflies start blinking again, as if on command. First, those in the center of the tree adapt to one rhythm, then neighboring beetles connect to them and gradually waves of lights flashing in unison spread throughout all the branches of the tree.
Males of different types of fireflies fly in search of flashes of a certain intensity and frequency - signals emitted by a female of their own kind. As soon as huge eyes catch the required light password, the male descends next to it, and the beetles, shining with lights for each other, perform the sacrament of marriage. However, this idyllic picture can sometimes be disturbed in the most nightmarish way due to the fault of females of some species belonging to the genus Photuris... These females emit signals that attract males of other species. And then they just eat them. A similar phenomenon is called aggressive mimicry.
Not all people have seen these amazing insects - fireflies, because they live only in some regions of central Russia. For example, in Japan, catching fireflies in July is considered one of the traditional royal fun that came from the distant Middle Ages. Due to their unusual properties, many legends and beliefs are associated with fireflies. Seeing for the first time the silvery-white lights in the velvet darkness of a summer night, you will truly believe in the magical belonging of these little creatures.
Appearance. Lifestyle
Unlike other insects, fireflies are especially active at night and in the evening in warm weather. In total, there are more than 2000 species of fireflies at the present time. In size, these creatures are small from 4 mm to 2 cm in length, and in the daytime you would not believe that these nondescript insects are so amazing at night. The firefly has a small head, large eyes. During the day, these unique insects are at rest, hiding in the grass and moss. At night they go hunting. Fireflies feed on the larvae of other insects, small spiders, sluggish snails, and ants.
Causes of the glow of fireflies
The question of why fireflies glow is still not fully understood. There is more than one point of view on this matter. Not all fireflies glow, in some species only their females glow. But the female, unlike the male, cannot fly. Many scientists believe that the "cold light" of firefly beetles is based on the biochemical process of bioluminescence.
In the body of an insect, two chemical processes take place, as a result of which two substances are produced - luciferin and luciferase. Luciferin, combining with oxygen, gives this coldish silvery light, and the second serves as a catalyst for this reaction. This light is so strong that you can read with it. In some manuscripts, it is mentioned that by collecting fireflies in vessels, they illuminated the living rooms.
Do you remember the Russian proverb: it shines, but it does not warm. She is the best suited for this situation. If it were different, then the firefly, simply, would have died. These amazing insects have a special organ that controls the possibility of glow.
Like all insects, fireflies have no respiratory organs, but only a whole complex system of tubes - tracheoles, through which oxygen is supplied. This system also plays a huge role in the ability to shine when necessary. The question of why the female firefly emits this mysterious enchanting light also remains open.
Some believe that with the help of light, the firefly defends itself from predators and nocturnal birds that can hunt them. Some insects have jaws or a pungent smell, while fireflies are protected by light. Others believe that this light serves as an identification mark for a female ready for fertilization.
There is a point of view that both females and males of fireflies glow, and the choice of partners for fertilization occurs precisely according to the intensity of the male's flickering. The fact is that it is the female firefly who serves as the initiator for mating, and it is precisely the flickering feature and the strength of the luminous flux that allow the male to enchant his partner. In the meantime, this issue is not fully understood, we can simply admire the flickering of small lights in the silence of the July night.
Reproduction
The female lays eggs on the leaves or on the ground. Soon, black larvae with yellow specks appear from them. They eat a lot and grow quickly, and by the way, they also glow. At the beginning of autumn, while it is still warm, they crawl under the bark of trees, where they spend the whole winter. In the spring they get out of the shelter, feed on them for several days, and then pupate. After two weeks, young fireflies appear.
From the eggs that the female laid after fertilization, large voracious black larvae with yellow spots appear. By the way, they also glow like adults. By autumn, they hide in the bark of trees, where they remain for the whole winter. And the next spring, waking up, they feed for several weeks, then pupate and after 1 - 2.5 weeks new adult fireflies develop from them, capable of surprising us with their mysterious night shine. - Read more on FB.ru.
Many are much more sympathetic to these glowing bugs than to most of their "relatives". They even call these insects affectionately - fireflies. Probably because in their habitats they create a special mysterious and romantic atmosphere at night.
What does a firefly look like and what does it glow from? This question is of interest to many, and in this article we will try to give an exhaustive answer to it.
Spreading
Fireflies are widespread in North America, Asia and Europe. They can be found in deciduous and tropical forests, meadows, meadows and swamps. This is a member of a large family of the order of beetles, which has an amazing ability to emit rather bright light.
Firefly is an insect belonging to the Firefly family (Lampyridae), the order of beetles. The family has over two thousand species. It is especially widely represented in the subtropics and tropics, rather limited in the temperate zone. In the countries of the former Soviet Union, there are seven genera and almost 20 species. And in our country, many people know what a firefly looks like. 15 species are registered in Russia.
For example, the nocturnal insects of Ivanovo worms, which spend the day in fallen leaves and dense grass, and go hunting at dusk. These fireflies live in the forest, where they hunt small spiders, small insects and snails. The female cannot fly. It is completely brownish-brown, with only three white segments on the underside of the abdomen. Here they emit a bright light.
Fireflies living in the Caucasus glow in flight. Sparks dance in the dense darkness and give the southern night a special charm.
What does a firefly look like?
I must say that in daylight these bugs look rather modest, even, one might say, nondescript. The body is narrow and elongated, the head is small with short antennae. And the size of the firefly cannot boast - on average, from one to two centimeters. The body of different species is colored dark gray, black or brown. Many species have pronounced sex differences: males are larger than females. In addition, males look very much like cockroaches. They can fly, but they do not glow.
What does a female firefly look like? It looks like a worm or a larva. She has no wings, so she is inactive. But it is the female that glows in most species, attracting males to herself. These beetles have no lungs, and oxygen is transmitted through special tubes - tracheoli. The supply of oxygen is "stored" in the mitochondria.
Lifestyle
Fireflies do not belong to collective insects, but despite this they often form rather large clusters. Many of our readers have no idea what fireflies look like, since they are difficult to see during the day: they rest, sitting on the stalks of plants or the ground, and lead an active life at night.
By the nature of the diet, different types of fireflies also differ. Harmless herbivorous beetles feed on nectar and pollen. Predatory individuals attack spiders, ants, snails and millipedes. There are species whose adults do not feed at all, they do not even have a mouth.
Why do fireflies glow?
Probably, many people in childhood, resting with their grandmother or in a camp on the Black Sea coast, saw fireflies flashing by in the evening, when it gets dark. Children love to collect unique insects in jars and admire how the fireflies glow. The organ of luminescence of these insects is the photophore. It is located in the lower part of the abdomen and consists of three layers. The lowest one is mirrored. It can reflect light. The upper one is a transparent cuticle. The middle layer contains photogenic cells that produce light. As you may have guessed, in its structure, this organ resembles a flashlight.
Scientists call this type of glow bioluminescence, which occurs as a result of the combination of oxygen cells with calcium, the pigment luciferin, the ATP molecule and the enzyme louciferase.
What kind of light do fireflies emit?
Unlike electric lamps, where most of the energy flows into useless heat, while the efficiency is no more than 10%, fireflies convert up to 98% of the energy into light. That is, it is cold. The glow of these bugs is attributed to the visible yellow-green part of the spectrum, corresponding to wavelengths up to 600 nm.
Interestingly, some types of fireflies are able to increase or decrease the intensity of light. And even emit an intermittent glow. When the insect's nervous system gives a signal to "turn on" the light, oxygen actively enters the photophore, and when it stops supplying the light "turns off".
And yet why do the fireflies glow? After all, not in order to please the gaze of a person? In fact, bioluminescence for fireflies is a means of communication between males and females. It is not easy for insects to signal their presence, but they also distinguish their partner by the frequency of flickering. North American and tropical species often perform choral serenades for their mates, flashing and dying simultaneously with the entire flock. A group of the opposite sex responds with the same signal.
Reproduction
When the mating period begins, the male firefly is in continuous search for a sign from his other half, ready to continue the genus. As soon as he finds him, he goes down to the chosen one. Different types of fireflies emit light at different frequencies, which in turn ensures that only members of the same species mate with each other.
Partner selection
The fireflies are matriarchy - the female chooses a partner. It determines it by the intensity of the glow. The brighter the light, the higher the frequency of its flickering, the more chances the male has to charm the female. In tropical forests, during collective serenades, trees wrapped in such necklaces shine brighter than shop windows in metropolitan areas.
Cases of mating games with a fatal outcome have been recorded. The female, using a light sign, attracts males of a different species. When unsuspecting fertilizers arrive, the insidious temptress eats them up.
After fertilization, larvae appear from the eggs laid by the female. What do firefly larvae look like? Quite large, voracious, black-colored worms with clearly visible yellow spots. Interestingly, they glow like adults. Closer to autumn, they hide in the bark of trees, where they hibernate.
The larvae develop slowly: in species living in the middle lane, the larvae hibernate, and in most subtropical species they grow for several weeks. The pupal stage lasts up to 2.5 weeks. The next spring, the larvae pupate and develop into new adults.
- The firefly, which emits the brightest light, lives in the tropics of America. It reaches a length of five centimeters. And his chest, besides the abdomen, also glows. Its light is 150 times brighter than that of its European relative.
- Scientists were able to isolate a gene that affects the glow. It was successfully introduced into plants, resulting in plantations that glow at night.
- Inhabitants of tropical settlements used these bugs as a kind of lamps. The bugs were placed in small containers and such primitive lanterns illuminated the dwellings.
- Every year in early summer, Japan hosts a firefly festival. Spectators come to the garden near the temple at dusk and enthusiastically watch the unusually beautiful flight of a huge number of glowing bugs.
- On the territory of Europe, the most common species is the common firefly, which is called the ivan worm. The bug got this unusual name due to the belief that it glows on the night of Ivan Kupala.
We hope that you have received answers to your questions about what a firefly looks like, where it lives and what kind of lifestyle it leads. These interesting insects have always aroused great interest in humans and, as you can see, for good reason.
Fireflies can appear and disappear in a certain area.
Their habitat is prairie, steppe and pampa.
Various species of fireflies are found in North and South America, Europe (UK), Russia, Asia (China, Malaysia and India), New Zealand, Australia.
Fireflies prey on small snails and slugs and should be looked for in such places as this prey. It is easier to observe insects from May to July, when they are. Fireflies are visible in the evening, for about two hours after dark. Fireflies are much less common in the forest than on open grassy grounds or near hedges. However, insects are not found near agricultural fertilized lands.
Firefly colony in Malaysia
A large colony of fireflies can be found near Kampung Kuatan, a small settlement near Kuala Selangor in Malaysia, on the coast of the Strait of Malacca. These fireflies belong to the Lampyridae family. The insect colony aroused the interest of entomologists back in the 70s of the 20th century.
The natural park, now open to the public at this site, is a combination of tropical and swamp forests. Fireflies live only in the mangrove forests of this reserve with an area of 296 hectares. During the day, they go into the grasses growing next to the mangrove trees. With the onset of night, they move to the mangroves standing along the banks of the river. In the trees, they feed on the sap of their leaves. Females and males of the insect glow in the dark with a greenish flickering light, attracting each other for mating.
Each tree can be inhabited by a separate subspecies of fireflies, and this is noticeable by their flickering, which differs from the glow of fireflies of another subspecies in the frequency of flickering.
Since 2000, the number of fireflies in the reserve has dropped significantly. Local residents believe that this is the construction of a dam in the upper reaches of the river.
Fireflies of Great Britain
In the British Isles, there are fireflies of the Lampyris noctiluca family. Although it is believed that members of this family prefer limestone soils, they have been observed in various parts of the UK.
Fireflies are found in gardens, hedges, and railroad embankments. Most often they can be found on abandoned railways. Insects are also observed on sheer cliffs, in woodlands, in the wastelands, in the hollows of Scotland and Wales.
Fireflies are also found on the island of Jersey, under the protection of the United Kingdom.
In general, fireflies are much more common in the southern British Isles.
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 on the place where the light is burning, you can see a nondescript worm-like segmented insect, in which the end of the abdomen glows green. This is what the female looks like common firefly (Lampyris noctiluca). People call him ivanov worm, ivanovsky worm due to the belief that the first time of the year 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 in the firefly looks like an ordinary normal beetle with hard elytra, while the female in the adult state remains similar to a larva and has no wings at all. The light is used to attract the male. A special organ that emits luminescence 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 acting as a mirror to reflect light. The luminiferous layer itself is penetrated by tracheas (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 that occurs with almost 100% efficiency, all the energy goes into light, with little or no heat. And now a little more detail on all this.
Common firefly (Lampyris noctiluca) is a member of the firefly family ( Lampyridae) of the 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. Females, on the other hand, resemble larvae in their appearance, have a worm-like body up to 18 mm long, and are wingless. Fireflies can be seen on forest edges, damp glades, on the shores of forest lakes and streams.
Luminous organs are the main ones in all senses of the word. In most fireflies, they are located at 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 by trachea and nerves. Each such cell is filled with "fuel", which is the substance luciferin. When the firefly breathes, air enters the luminous organ through the trachea, 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 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 (reflector mirror) and allow not to waste valuable energy in vain. However, these insects might not care about saving, because the performance of their luminous organs can be the envy of any technician. The efficiency of fireflies reaches a fantastic 98%! This means that only 2% of the energy is wasted, and in the creations of human hands (cars, electrical appliances), 60 to 96% of the energy is wasted.
Several chemical compounds are involved in the glow reaction. One of them is resistant to heat and is present in small quantities - luciferin. Another substance is the enzyme luciferase. Also, for the glow reaction, adenosine triphosphoric acid (ATP) is also needed. 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; catalization by luciferase significantly increases its rate. ATP is required as a cofactor.
Light arises during the transition of oxyluciferin from the excited state to the ground state. In this case, oxyluciferin is bound to an enzyme molecule and, depending on the hydrophobicity of the microenvironment of excited oxyluciferin, the emitted light varies in different species of fireflies from yellow-green (with a more hydrophobic microenvironment) to red (with a less hydrophobic one). 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 the energy of the reaction is transformed into light without emitting heat.
All beetles contain the same luciferin. Luciferases, on the other hand, are different in different species. It follows that the change in the color of the glow 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 glow is emitted by photogenic granules located in the cytoplasm. When examined in ultraviolet rays of fresh sections of photogenic cells, 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 in comparison with classical examples of luminescence, approaching unity. In other words, for each luciferin molecule involved in the reaction, one quantum of light is emitted.
Fireflies are predators, feeding on insects and molluscs. Firefly larvae lead a wandering life, like the larvae of ground beetles. The larvae feed on small invertebrates, mainly terrestrial molluscs, in the shells of which 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 specks appear from them. They eat a lot and grow quickly, and by the way, they also glow. At the beginning of autumn, while it is still warm, they crawl under the bark of trees, where they spend the whole winter. In the spring they get out of the shelter, feed on them for several days, and then pupate. After two weeks, young fireflies appear.
Looking at the bright flicker of fireflies, since ancient times, people have wondered why not use them for useful purposes. The Indians attached them to moccasins to highlight trails 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.