What a firefly looks like and why it glows: interesting facts. To record firefly ordinary Little tricks of the female half

fine summer evening, when the first twilight is just beginning to descend on the earth, among the tall blades of grass you can easily see the mysterious glow. Coming a little closer and looking closely, you will find with a smile that these are your old acquaintances - fireflies.

These bugs, known to everyone since childhood, still intrigue and beckon. However, the question of why they emit light remains open.

Fireflies are a family of terrestrial nocturnal beetles that have the ability to produce a cool yellowish-green light in the dark. They are dark brown in color and reach a length of one and a half centimeters. In the world as a whole, there are about 2000 of their varieties and almost all bugs, like their larvae, are predators. They feed on invertebrates such as slugs and snails.

These insects are most common in tropical and subtropical climate, are less common in temperate geographic zone. They glow mainly for reasons of communication, and emit sexual, search, protective and territorial signals.

Not all varieties of fireflies have the full spectrum of the above signals. Basically, they are limited to conscripts only. Why does the phenomenon of glow occur and how are the "lanterns" of fireflies arranged?

Scientific explanation of yellow-green beacons

The ability for bioluminescence, for the production of light, in these insects is primarily due to the presence of special organs of luminescence, photocytes.

At the tip of the abdomen, under the transparent part of the shell, fireflies have several segments in which, under the influence of luciferase, luciferin and oxygen are mixed. The process of oxidation or breakdown of luciferin and becomes main reason why beetles give off light.

Most members of the family are capable of dimming incandescent light or producing short, intermittent flashes. And some fireflies glow synchronously. The answer to the question why the bugs do not glow all the time will be quite common in scientific world opinion: fireflies can control the access of oxygen to the glow organ.

A bit of romance or it's time for a date

Studying fireflies, entomologists have come to the conclusion that the main reason why bugs flicker in the dark is their desire to attract a potential partner. Each species has its own distinctive signals, showing different light patterns. So, female fireflies, sitting on a leaf, send certain signals to male fireflies, which soar in the air and look for their “companion”.

Seeing a familiar light, they head straight for it. Once near, the fireflies mate, and the female immediately lays fertilized eggs in the ground, from which larvae will hatch later, flat in shape and brown in color. Some larvae glow until the very moment of transformation into beetles.

Small tricks of the female half

Attracting a potential partner is far from the only reason why fireflies use their gift for bioluminescence. Some types of twinkling beetles can produce light for completely opposite purposes.

For example, fireflies belonging to the species Photuris are able to exactly copy the signals of fireflies of another species. Thus, females deceive gullible male strangers.

When they fly up in the hope of mating, the Photuris females devour them and get enough nutrients for themselves and their own kind of larvae ready to hatch from the ground.

Non-standard use of natural lanterns

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.

AT modern world the question is why and how fireflies acquired the ability to bioluminescence, how can their gift be used in scientific purposes, excites the mind of more than one entomologist. Scientists in the course of lengthy trial and error even managed to find a gene that causes the cells of these insects to produce luciferase.

Once this gene was isolated, it was transplanted into a tobacco leaf and seeded into an entire plantation. The sprout crop glowed at the onset of darkness. Experiments with fireflies are not over yet: a lot of new and interesting discoveries await us ahead.

A firefly is an insect that belongs to the order Coleoptera (or beetles), the suborder polyphagous beetles, the family of fireflies (lampyridae) (lat. Lampyridae).

Fireflies get their name from the fact that their eggs, larvae and adults are able to glow. The oldest written reference to fireflies is in a Japanese poetry collection from the late 8th century.

Firefly - description and photo. What does a firefly look like?

Fireflies are small insects ranging in size from 4 mm to 3 cm. Most of them have a flattened elongated body covered with hairs and a structure characteristic of all beetles, in which:

• 4 wings, the upper two of which turned into elytra, with punctures and sometimes traces of ribs;

• movable head, decorated with large compound eyes, completely or partially covered by the pronotum;

• filiform, comb-shaped or serrated antennae, consisting of 11 segments;

• gnawing type mouth apparatus (more often it is observed in larvae and females; in adult males it is reduced).

Males of many species, similar to ordinary beetles, are very different from females, which are more reminiscent of larvae or small worms with legs. Such representatives have a dark brown body on 3 pairs of short limbs, simple large eyes and no wings or elytra at all. As a result, they cannot fly. Their antennae are small, consisting of three segments, and the indistinguishable head is hidden behind the neck shield. The less developed the female, the more she glows.

Fireflies are not brightly colored: representatives of brown are more common, but their covers can also contain black and brown tones. These insects have relatively soft and flexible, moderately sclerotized body integuments. Unlike other beetles, the elytra of fireflies are very light, so insects were previously classified as soft beetles (lat. Cantharidae), but then they were separated into a separate family.

Why do fireflies glow?

Most representatives of the firefly family are known for their ability to emit a phosphorescent glow, which is especially noticeable in the dark. In some species, only males can glow, in others only females, in others, both (for example, Italian fireflies). Males emit bright light in flight. Females are inactive and usually glow brightly on the soil surface. There are also fireflies that do not have this ability at all, while in many species the light comes even from the larvae and eggs.

By the way, few land animals generally have the phenomenon of bioluminescence (chemical glow). Fungal mosquito larvae, springtails (springtails), fire flies, jumping spiders and representatives of beetles, such as fire-bearing click beetles (pyrophorus) from the West Indies, are known to be capable of this. But if we count marine life, then there are at least 800 species of luminous animals on Earth.

The organs that allow fireflies to emit rays are photogenic cells (lanterns), abundantly entwined with nerves and tracheae (air tubes). Outwardly, lanterns look like yellowish spots on the underside of the abdomen, covered with a transparent film (cuticle). They can be located on the last segments of the abdomen or evenly distributed over the body of the insect. Beneath these cells lie others filled with uric acid crystals and capable of reflecting light. Together, these cells work only if there is a nerve impulse from the insect's brain. Oxygen enters the photogenic cell through the trachea and, with the help of the luciferase enzyme, which accelerates the reaction, oxidizes the compound of luciferin (light-emitting biological pigment) and ATP (adenosine triphosphoric acid). Thanks to this, the firefly glows, emitting light of blue, yellow, red or green. Males and females of the same species most often emit rays of a similar color, but there are exceptions. The color of the glow depends on temperature and acidity (pH) environment, as well as on the structure of luciferase.

Beetles themselves regulate the glow, they can strengthen or weaken it, make it intermittent or continuous. Each species has its own unique system phosphoric radiation. Depending on the purpose, the glow of fireflies can be pulsating, flashing, stable, fading, bright or dim. The female of each species reacts only to the signals of the male with a certain frequency and intensity of light, that is, his regime. With a special rhythm of light emission, beetles not only attract partners, but also scare away predators and guard the borders of their territories. Distinguish:

• search and calling signals in males;
• signals of consent, refusal and post-copulatory signals in females;
• signals of aggression, protest and even light mimicry.

Interestingly, fireflies spend about 98% of their energy emitting light, while an ordinary electric light bulb (incandescent lamp) converts only 4% of energy into light, the rest of the energy is dissipated as heat.

Fireflies that are diurnal often do not need the ability to emit light, because they do not have it. But those diurnal representatives who live in caves or in the dark corners of the forest also turn on their "flashlights". The eggs of all types of fireflies also emit light at first, but it soon fades. During the day, the light of a firefly can be seen if you cover the insect with two palms or move it to a dark place.

By the way, fireflies also give signals using the direction of flight. For example, representatives of one species fly in a straight line, representatives of another species fly in a broken line.

Types of light signals of fireflies.

V. F. Bak divided all light signals of fireflies into 4 types:

• continuous glow

This is how adult beetles belonging to the genus Phengodes glow, and the eggs of all fireflies, without exception. Neither external temperature nor lighting affect the brightness of the rays of this uncontrolled type of glow.

• intermittent glow

Depending on the factors external environment and internal state insect, it can be weak or strong light. It may fade away for a while. This is how most larvae shine.

• Ripple

This type of luminescence, in which periods of radiation and absence of light are repeated at certain intervals, is characteristic of the tropical genera Luciola and Pteroptix.

• Flashes

There is no time dependence between the intervals of flashes and their absence in this type of glow. This type of signal is typical for most fireflies, especially in temperate latitudes. In conditions given climate The ability of insects to emit light is highly dependent on environmental factors.

HA. Lloyd also identified a fifth type of glow:

• flicker

This type of light signal is a series of short flashes (frequency from 5 to 30 Hz) that appear immediately after each other. It is found in all subfamilies, and its presence does not depend on the place and habitat.

Firefly communication systems.

There are 2 types of communication systems in lampyrids.

1. In the first system, an individual of one sex (more often a female) emits specific calling signals and attracts a representative of the opposite sex, for whom the presence of its own light organs is not mandatory. This type of communication is typical for fireflies of the genera Phengodes, Lampyris, Arachnocampa, Diplocadon, Dioptoma (Cantheroidae).
2. In the system of the second type, individuals of the same sex (more often flying males) emit calling signals, to which non-flying females give sex- and species-specific responses. This way of communication is characteristic of many species from the subfamilies Lampyrinae (genus Photinus) and Photurinae living in North and South America.

This division is not absolute, since there are species with an intermediate type of communication and with a more perfect dialogue system of luminescence (in European species Luciola italica and Luciola mingrelica).

Synchronous flashing of fireflies.

In the tropics, many species of bugs from the Lampyridae family seem to shine together. They simultaneously light their "lanterns" and extinguish them at the same time. Scientists called this phenomenon the synchronous flashing of fireflies. The process of synchronous flashing of fireflies is not yet fully understood, and there are several versions of how insects manage to shine at the same time. According to one of them, there is a leader within a group of beetles of the same species, and he serves as the conductor of this “choir”. And since all representatives know the frequency (break time and glow time), they manage to do it very amicably. Synchronously flashing, mainly male lampiridae. Moreover, all researchers are inclined to the version that the synchronization of firefly signals is associated with the sexual behavior of insects. By increasing the density of the population, they have an increased opportunity to find a partner for mating. Scientists also noticed that the synchronicity of the light of insects can be broken if you hang a lamp next to them. But with the termination of its work, the process is restored.

The first mention of this phenomenon dates back to 1680 - this is a description that E. Kaempfer made after traveling to Bangkok. Subsequently, many claims were made about the observation of this phenomenon in Texas (USA), Japan, Thailand, Malaysia and the highlands of New Guinea. Especially many of these types of fireflies live in Malaysia: there this phenomenon locals called "kelip-kelip". In the USA in national park Elcomont (Great Smoky Mountains) visitors watch the synchronous glow of representatives of the species Photinus carolinus.

Where do fireflies live?

Fireflies are fairly common, heat-loving insects that live in all parts of the world:

• in North and South America;
• in Africa;
• in Australia and New Zealand;
• in Europe (including the UK);
• in Asia (Malaysia, China, India, Japan, Indonesia and the Philippines).

Most fireflies are found in the Northern Hemisphere. Many of them live in warm countries, that is, in the tropical and subtropical regions of our planet. Some varieties are found in temperate latitudes. 20 species of fireflies live in Russia, which can be found throughout the territory, except for the north: Far East, in the European part and in Siberia. They can be found in deciduous forests, in swamps, near rivers and lakes, in glades.

Fireflies do not like to live in groups, they are loners, but they often form temporary clusters. Most of fireflies are nocturnal animals, but there are also those that are active during daylight hours. During the day, insects rest on the grass, hiding under bark, stones or in silt, and at night, those that are able to fly do it smoothly and quickly. AT cold weather they can often be seen on the surface of the earth.

What do fireflies eat?

Both larvae and adults are more likely to be predators, although there are fireflies that feed on nectar and pollen from flowers, as well as rotting plants. Carnivorous bugs prey on other insects, scoop caterpillars, molluscs, centipedes, earthworms, and even their fellows. Some females living in the tropics (for example, from the genus Photuris), after mating, imitate the rhythm of the glow of males of another species in order to eat them and get nutrients for the development of their offspring.

Adult females feed more often than males. Many males do not eat at all and die after a few matings, although there is other evidence that all adults eat food.

The firefly larva has a retractable brush on the last segment of the abdomen. She is needed in order to clean off the mucus remaining on her small head after eating snails and slugs. All firefly larvae are active predators. Basically, they eat mollusks and often settle in their hard shells.

Firefly breeding.

Like all beetles, fireflies develop with complete metamorphosis. The life cycle of these insects consists of 4 stages:

1. Egg (3-4 weeks),
2. Larva, or nymph (from 3 months to 1.5 years),
3. Pupa (1-2 weeks),
4. Imago, or adult (3-4 months).

Females and males mate on the ground or on low plants for 1-3 hours, after which the female lays up to 100 eggs in soil depressions, in debris, on the underside of leaves or in moss. The eggs of common fireflies look like mother-of-pearl-yellow pebbles washed with water. Their shells are thin, and the “head” side of the eggs contains the embryo, which is visible through a transparent film.

After 3-4 weeks, the eggs hatch into terrestrial or aquatic larvae, which are voracious predators. The body of the larvae is dark, slightly flattened, with long running legs. At aquatic species lateral abdominal gills developed. Small elongated or square head of nymphs with three-segmented antennae strongly retracted into prothorax. On the sides of the head is located on 1 light eye. The heavily sclerotized mandibles (mandibles) of the larvae are sickle-shaped, inside of which there is a sucking canal. Unlike adult insects, nymphs do not have an upper lip.

The larvae settle on the surface of the soil - under stones, in the forest litter, in shells of mollusks. Nymphs of some species of fireflies pupate in the same autumn, but mostly they survive the winter and turn into pupae only in spring. The larvae pupate in the soil or hang themselves on the bark of a tree, as caterpillars do. After 1-2 weeks, beetles crawl out of the pupae.

General life cycle fireflies last 1-2 years.

Types of fireflies, photos and names.

In total, entomologists count about 2,000 species of fireflies. Let's talk about the most famous of them.

• common firefly ( he is large firefly) (lat. Lampyris noctiluca) has the popular names Ivanov worm or Ivanovo worm. The appearance of the insect was associated with the holiday of Ivan Kupala, because it is with the advent of summer that fireflies begin to mating season. Hence the popular nickname appeared, which was given to the female, very similar to a worm. A large firefly is a beetle with a characteristic firefly appearance. The size of males reaches 11-15 mm, females - 11-18 mm. The insect has a flat, villous body and all other signs of the family and order. The male and female of this species are very different from each other. The female is similar to a larva and leads a sedentary ground lifestyle. Both sexes have the ability to bioluminescence. But in the female, this is much more pronounced; at dusk, she emits a rather bright glow. The male flies well, but glows very weakly, almost imperceptibly for observers. Obviously, it is the female who gives the signal to the partner.

• Water firefly (lat. Luciola cruciata)- a common inhabitant of the rice fields of Japan. Lives only in wet silt or directly in water. Hunts at night for molluscs, including intermediate hosts sucker worms. When hunting, it shines very brightly, emitting blue light.

• Common eastern firefly (fire photinus) (lat. Photinus pyralis) lives in North America. Males from the genus Photinus glow only on takeoff and fly in a zigzag path, while females use mimic illumination to eat males of other species. From representatives of this genus, American scientists isolate the enzyme luciferase in order to use it in biological practice. The common eastern firefly is the most common North America. This is a nocturnal beetle with a dark brown body 11-14 mm long. Due to the bright light, it is clearly visible on the soil surface. The females of this species are similar to worms. Fire photinus larvae live from 1 to 2 years and hide in damp places - next to streams, under bark and on the ground. They spend the winter buried in the ground. Both adult insects and their larvae are predators, eating worms and snails.

• Pennsylvania firefly (lat. Photuris pennsylvanica) lives only in Canada and the USA. An adult beetle reaches a size of 2 cm. It has a flat black body, red eyes and yellow underwings. Photogenic cells are located on the last segments of its abdomen. The larva of this insect was nicknamed the "glowing worm" for its ability to bioluminescence. Worm-like females of this species also have the ability to light mimicry, they mimic the signals of the firefly species Photinus in order to grab and eat their males.

• Cyphonocerus ruficollis- the most primitive and little-studied type of fireflies. It lives in North America and Eurasia. In Russia, the insect is found in Primorye, where females and males actively glow in August. The beetle is included in the Red Book of Russia.

• Red firefly (pyrocelium firefly) (lat. Pyrocaelia rufa)- a rare and little-studied species that lives in the Far East of Russia. Its length can reach 15 mm. It is called the red firefly because its shield and rounded pronotum have orange tint. The elytra of the beetle are dark brown, the antennae are saw-shaped and small. The larval stage of this insect lasts 2 years. You can find the larva in the grass, under stones or in the forest floor. Adult males fly and glow.
• Fir firefly (lat. Pterotus obscuripennis)- small black beetle orange head and sawtooth antennae (shackles). Females of this species fly and glow, while males lose their ability to emit light after turning into an adult insect. Fir firefly beetles live in the forests of North America.

• Central European worm (luminous worm) (lat. Lamprohiza splendidula)- inhabitant of the center of Europe. The pronotum of the male beetle has distinct transparent spots, and the rest of its body is colored light brown. The body length of the insect varies from 10 to 15 mm. Males shine especially brightly in flight. The females are worm-like and also capable of emitting bright light. The organs of light production are located in Central European worms not only at the end of the abdomen, but also in the second segment of the chest. The larvae of this species can also glow. They have a black hairy body with yellow-pink dots on the sides.

Lampyris noctiluca (Linnaeus, 1758)
Order Coleoptera, or Beetles - Coleoptera
Firefly family - Lampyridae

Spreading. In the Moscow region fairly widespread. On the territory of Moscow, the habitat of the species was established in 1969 in the south. parts Elk Island(one). In 2005-2007 repeatedly noted in the valley of the river Skhodnya in Kurkino in the tract " Birch Grove» (2).

Number. Only 1 population is currently known in Moscow. In the tract "Birch Grove" in Kurkino in 2005, 4-5 ind. per 1 km of the route (2).

habitation features. Leads a nocturnal lifestyle, has luminous organs. Predator, larvae and adults eat small mollusks and insects (3). In Moscow lives on the outskirts of the city in a bright mixed forest(2). In Losiny Ostrov, fireflies were observed along the edges of glades, which were mowed almost every year, but once (1).

negative factors. Trampling of the ground cover and grassy vegetation. Continuous and frequent mowing of grass, burning dry last year's grass. Root transformation natural communities in the park improvement of forests and glades. Planned construction of a district park in the tract "Birch Grove" in the PP "Valley of the River Skhodnya in Kurkino".

Security measures taken. The species was included in Appendix 1 to the Red Book of Moscow in 2001. The place of its modern habitat is located in a specially protected natural area - in the Skhodni River Valley in Kurkino.

Change the state of a view. AT recent decades no fireflies were observed in the urban part of Losiny Ostrov. The condition of the species on the territory of the Skhodnya River Valley in Kurkino is satisfactory, however, this is the only known population in Moscow, the location of which is under the threat of radical transformation. The species is listed in the Red Book of Moscow with KR 1.

Necessary measures for the conservation of the species. Allocation of a known habitat of a species in the memory with a regime that provides only for natural restoration and environmental protection measures, first of all - the maintenance of the biotope in natural state. Refusal to build a district park in the Birch Grove tract, limiting its recreational use to walking. Strengthening control over compliance with the ban on spring fires.

Sources of information. 1. B.L. Samoilov, b.s. 2. Author's data. 3. Medvedev, 1965. Author: O.O. Tolstenkov

common firefly, or Ivanov worm, Ivanovo worm(lat. Lampyris noctiluca) is a species of firefly beetle, common in Europe and Asia, also found in North America.

It got its common name because of the belief that for the first time in a year it appears on the night of Ivan Kupala.

• 1 Description
• 2 Gallery
• 3 notes
• 4 Links

Description

The beetle is 1.2-1.8 cm long. They have reduced wings. Males have a cigar-shaped body and a rather large head with large hemispherical eyes. Like the rest of the family, the common firefly has the ability to emit a bioluminescent glow that serves as a means of attracting and detecting a sexual partner. Organ, emitting light, is located under the transparent cuticle at the end of the abdomen on the underside and is developed in both males and females. Only females waiting for males on the ground or vegetation can emit bright light; males practically do not emit light. Light is emitted when luciferin is oxidized.

Gallery

• Lampyridae - Lampyris noctiluc

Notes

1. 1 2 Striganova B.R., Zakharov A.A. Five-language Dictionary of Animal Names: Insects (Latin-Russian-English-German-French) / Ed. Dr. Biol. sciences, prof. B. R. Striganova. - M.: RUSSO, 2000. - S. 122. - 1060 copies. - ISBN 5-88721-162-8.
2. 1 2 Sakharov Ivan Petrovich June month.

One of the most amazing natural phenomena is the ability of animals to emit light. This phenomenon has the scientific name of bioluminescence. Most of luminous organisms found in the world's oceans. On the continent, you can also see such a miracle of nature - this is a firefly insect. This beetle is not of particular value to humans, but it is of interest due to its unique abilities.

Fireflies are small insects. Their body length does not exceed 25 mm. The color of the covers is varied, but black, gray and brown shades predominate. The chitinous cover is not very dense, most often soft. The head of the insect is small. It has large compound eyes and short antennae that come in a variety of shapes.

Fireflies are sexually dimorphic. Males have a typical beetle structure and are somewhat similar in appearance to cockroaches. Females, on the other hand, are devoid of wings and elytra, therefore they are more similar to insect larvae. The firefly larva has a dark color and light spots on the sides.

Behavioral features

Fireflies are heat-loving insects, so most species live in tropical and subtropical zones. AT temperate zone 20 species are found, 15 of which are found on the territory of Russia. All adult fireflies are nocturnal terrestrial. The larvae can live both in water bodies and on land.

These insects can be found in meadows, near swamps, as well as in the wilds of deciduous forests. Fireflies, although not social insects, often form large aggregations. In the daytime, the beetles are inactive, they sit on the grass all the time, waiting for the sunset. At night, insects wake up and begin to fly quickly.

Food various kinds fireflies are very different. Depending on the diet, insects are divided into main groups:

1. Vegetarians eat nectar and pollen.
2. Predators (including cannibals) - eat various invertebrates.
3. Species in which adult insects have an atrophied mouth, therefore, do not feed, but consume the nutrients accumulated in the fat body.

Reproduction and life cycle

At the beginning of summer, the mating season begins for fireflies, after which the fertilized females lay their eggs in the ground. Soon, hungry larvae emerge from these eggs. Regardless of the species, the larvae are always predators feeding on mollusks. After a meal, the larvae usually hide in the shells of their victims.

The development of fireflies is quite slow - from six months to several years. Pupation occurs under the bark of trees or under blocks of stones. In the pupal stage, the insect stays for 1–2.5 weeks. In the spring, an adult beetle crawls out, and the cycle begins again.

glow

Each luminous insect has special organs - lanterns that generate light. Depending on the species, the number, shape and placement of these organs may vary. Laterns are a collection of nerve endings, tracheas and photogenic cells. Below them are reflective cells filled with uric acid crystals.

Chemical reactions at the heart of the glow

To generate light in photogenic cells, four substances must be present:

• luciferin;
• the enzyme luciferase;
• oxygen;
• ATP as an energy source.

Light is released during the oxidation of the substance luciferin by oxygen. Luciferase only speeds up this process. The reaction goes through the following steps

1. Luciferin, when interacting with an ATP molecule, turns into luciferyl adenylate.
2. Luciferyladenylate interacts with oxygen, turns into oxyluciferin with the release of AMP and light.

The color of the glow depends on the composition of the luciferase, which differs in many species.

Glow as a method of communication

Glow is used by beetles as a way to convey information. Entomologists have learned to distinguish between the signals that are used by insects during the mating season: the calls of males, the consent and refusal of females, as well as post-copulatory signals. In addition, fireflies with the help of luminescence can express anger, mark territory, and even defend themselves.

Interesting fact. Female predators of the genus Photuris are capable of emitting light signals inherent in the genus Photinus. Attracted males flock to the call and become the prey of bloodthirsty liars.

Glow types

Scientists have noticed that different types fireflies emit typical light signals:

• Continuous glow. The generation of light in this case occurs constantly, is not controlled by the insect and does not depend on environmental conditions. This type of luminescence is characteristic of eggs and larvae of all species of beetles, as well as adults of fireflies of the genus Phengodes.
• Intermittent glow. insects generate light long time, but its brightness can gradually change depending on daily rhythms, the external environment and changes in the body of the beetle itself.
• Pulsation. This type of glow is a regular flash of light that is regulated by circadian rhythms.
• Flashes. The most common type of glow. It differs from pulsation by the ability to regulate the duration of each cycle, the brightness of light and other indicators by internal and external factors.

Interesting fact. Some types of tropical fireflies are able to regulate the frequency of glow so precisely that insects, collected together, “light up” and “go out” at the same time.

Why fireflies glow: Video