Lampyridae is a family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 of insects in the beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...

Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...

 Coleoptera. They are winged beetles, and commonly called fireflies or lightning bugs for their conspicuous crepuscular
Crepuscular animals are those that are active primarily during twilight, that is during dawn and dusk. The word is derived from the Latin word crepusculum, meaning "twilight." Crepuscular is, thus, in contrast with diurnal and nocturnal behavior. Crepuscular animals may also be active on a bright...

 use of bioluminescence
Bioluminescence is the production and emission of light by a living organism. Its name is a hybrid word, originating from the Greek bios for "living" and the Latin lumen "light". Bioluminescence is a naturally occurring form of chemiluminescence where energy is released by a chemical reaction in...

 to attract mates or prey. Fireflies produce a "cold light", with no infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...

 or ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...

 frequencies. This chemically-produced light from the lower abdomen may be yellow, green, or pale-red, with wavelength
In physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...

s from 510 to 670 nanometers.

About 2,000 species of firefly are found in temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...

 and tropical environments. Many are in marsh
In geography, a marsh, or morass, is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and features grasses, rushes, reeds, typhas, sedges, other herbaceous plants, and moss....

es or in wet, wooded areas where their larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...

e have abundant sources of food. These larvae emit light and are often called "glowworm
Glowworm, or glow worm, is the common name for various groups of insect larvae and adult larviform females that glow through bioluminescence. They may sometimes resemble worms, but all are insects .-Classification:Major families are:* Lampyridae , found around the world...

s", in particular, in Eurasia. In the Americas, "glow worm" also refers to the related Phengodidae
The beetle family Phengodidae is known also as glowworm beetles, whose larvae are known as glowworms. The females and larvae have bioluminescent organs. They occur throughout the New World from extreme southern Canada to Chile...

. In many species, both male and female fireflies have the ability to fly, but in some species, females are flightless.


Fireflies, also known as glow worms, tend to be brown and soft-bodied, often with the elytra more leathery than in other beetles. Though the females of some species are similar in appearance to males, larviform female
Larviform female
Larviform female is biological phenomenon occurring in some species, where the females in the adult stage of metamorphosis resemble the larvae to various degrees. Typically, the female is wingless and generally larger than the male...

s are found in many other firefly species. These females can often be distinguished from the larvae only because they have compound eyes. The most commonly known fireflies are nocturnal, though there are numerous species that are diurnal. Most diurnal species are nonluminescent, though some species that remain in shadowy areas can produce light.

A few days after mating, a female lays her fertilized eggs on or just below the surface of the ground. The eggs hatch three to four weeks later, and the larvae feed until the end of the summer. The larvae are commonly called glowworms, not to be confused with the distinct beetle family Phengodidae
The beetle family Phengodidae is known also as glowworm beetles, whose larvae are known as glowworms. The females and larvae have bioluminescent organs. They occur throughout the New World from extreme southern Canada to Chile...

 or fly genus Arachnocampa
Arachnocampa is a genus of four fungus gnat species which are, in their larval stage, glowworms. They are found mostly in New Zealand and Australia in caves and grottos, or sheltered places in forests....

. Lampyrid larvae have simple eyes. The term glowworm is also used for both adults and larvae of species such as Lampyris noctiluca
Lampyris noctiluca
Lampyris noctiluca, the common glow-worm of Europe , is a firefly species of the genus Lampyris. These are beetles, as evidenced by the hard cases which close over the wings when they are not in use....

, the common European glowworm, in which only the nonflying adult females glow brightly and the flying males glow only weakly and intermittently.

Fireflies hibernate over winter
Insect winter ecology
Insect winter ecology entails the overwinter survival strategies of insects, which are in many respects more similar to those of plants than to many other animals, such as mammals and birds. This is because unlike those animals, which can generate their own heat internally , insects must rely on...

 during the larval stage, some species for several years. Some do this by burrowing underground, while others find places on or under the bark of trees. They emerge in the spring. After several weeks of feeding, they pupa
A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...

te for 1.0 to 2.5 weeks and emerge as adults. The larvae of most species are specialized predators and feed on other larvae, terrestrial snail
Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...

s, and slugs. One such species is Alecton discoidalis
Alecton discoidalis
Alecton discoidalis is a species of firefly in the beetle family Lampyridae, commonly known as the Cuban endemic firefly. The larvae of this species are predators on both pulmonate and operculate land snails. Alecton discoidalis is the type species of the genus Alecton.-Distribution:Alecton is the...

, which is found in Cuba. Some are so specialized, they have grooved mandibles
Mandible (insect)
Insect mandibles are a pair of appendages near the insect’s mouth, and the most anterior of the three pairs of oral appendages . Their function is typically to grasp, crush, or cut the insect’s food, or to defend against predators or rivals...

 that deliver digestive fluids directly to their prey. Adult diet varies. Some are predatory, while others feed on plant pollen
Pollen is a fine to coarse powder containing the microgametophytes of seed plants, which produce the male gametes . Pollen grains have a hard coat that protects the sperm cells during the process of their movement from the stamens to the pistil of flowering plants or from the male cone to the...

 or nectar.

Most fireflies are quite distasteful and sometimes poisonous to vertebrate predators. This is due at least in part to a group of steroid pyrones known as lucibufagins (LBGs), which are similar to cardiotonic bufadienolides
Bufadienolide is a type of steroid. Its derivatives are collectively known as bufadienolides, including many in the form of bufadienolide glycosides . These are a type of cardiac glycoside, the other being the cardenolide gylcosides...

 found in some poisonous toads.

Light and chemical production

Light production in fireflies is due to a type of chemical reaction called bioluminescence
Bioluminescence is the production and emission of light by a living organism. Its name is a hybrid word, originating from the Greek bios for "living" and the Latin lumen "light". Bioluminescence is a naturally occurring form of chemiluminescence where energy is released by a chemical reaction in...

. This process occurs in specialised light-emitting organs, usually on a firefly's lower abdomen. The enzyme luciferase
Luciferase is a generic term for the class of oxidative enzymes used in bioluminescence and is distinct from a photoprotein. One famous example is the firefly luciferase from the firefly Photinus pyralis. "Firefly luciferase" as a laboratory reagent usually refers to P...

 acts on the luciferin
Firefly luciferin
Firefly luciferin is the luciferin, or light-emitting compound, found in many firefly species. It is the substrate of luciferase , which is responsible for the characteristic yellow light emission from many firefly species...

, in the presence of magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...

 ions, ATP
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...

, and oxygen to produce light. Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

s coding for these substances have been inserted into many different organisms (see Luciferase – Applications). Firefly luciferase is used in forensics
Forensic science is the application of a broad spectrum of sciences to answer questions of interest to a legal system. This may be in relation to a crime or a civil action...

, and the enzyme has medical uses — in particular, for detecting the presence of ATP or magnesium. It has been speculated that Baroque painter Caravaggio
Michelangelo Merisi da Caravaggio was an Italian artist active in Rome, Naples, Malta, and Sicily between 1593 and 1610. His paintings, which combine a realistic observation of the human state, both physical and emotional, with a dramatic use of lighting, had a formative influence on the Baroque...

 may have prepared his canvases with a powder of dried fireflies to create a photosensitive surface on which he projected the image to be painted.

All fireflies glow as larvae. Bioluminescence serves a different function in lampyrid larvae than it does in adults. It appears to be a warning signal to predators, since many firefly larvae contain chemicals that are distasteful or toxic.

Light in adult beetles was originally thought to used for similar warning purposes, but its primary purpose is now thought to be used in mate selection. Fireflies are a classic example of an organism that uses bioluminescence for sexual selection. They have evolved a variety of ways to communicate with mates in courtships: steady glows, flashing, and the use of chemical signals unrelated to photic systems.

Some species, especially lightning bugs of the genera
Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...

Photinus (beetle)
The rover fireflies are a genus of fireflies . They are the type genus of tribe Photinini in subfamily Lampyrinae. This genus contains, for example, the common eastern firefly , the state insect of Tennessee.Male Photinus beetles emit a flashing light pattern to signal for females...

, Photuris
Photuris (genus)
Photuris is a genus of fireflies wherein are the femme fatale fireflies of North America. This common name refers to the fact that the females of these predatory beetles mimic the light signals of other firefly species' males, to attract, kill, and eat them...

, and Pyractomena, are distinguished by the unique courtship flash patterns emitted by flying males in search of females. In general, females of the Photinus genus do not fly, but do give a flash response to males of their own species.

Tropical fireflies, in particular, in Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...

, routinely synchronise their flashes among large groups. This phenomenon is explained as phase synchronization
Phase synchronization
Phase synchronization is the process by which two or more cyclic signals tend to oscillate with a repeating sequence of relative phase angles.Phase synchronisation is usually applied to two waveforms of the same frequency with identical phase angles with each cycle...

 and spontaneous order. At night along river banks in the Malaysian jungles (the most notable ones found near Kuala Selangor), fireflies (kelip-kelip in the Malay language or Bahasa Malaysia) synchronise their light emissions precisely. Current hypotheses about the causes of this behavior involve diet, social interaction, and altitude. In the Philippines, thousands of fireflies can be seen all year-round in the town of Donsol (called aninipot or totonbalagon in Bicol
Bikol language
Central Bicolano , is one of the individual languages of the Bikol languages. It belongs to Coastal Bikol. It is spoken in Bicol Region of the Philippines .-Bikol-Naga:...

). In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, one of the most famous sightings of fireflies blinking in unison
In music, the word unison can be applied in more than one way. In general terms, it may refer to two notes sounding the same pitch, often but not always at the same time; or to the same musical voice being sounded by several voices or instruments together, either at the same pitch or at a distance...

 occurs annually near Elkmont, Tennessee
Elkmont, Tennessee
Elkmont is a region situated in the upper Little River Valley of the Great Smoky Mountains of Sevier County, in the U.S. state of Tennessee. Throughout its history, the valley has been home to a pioneer Appalachian community, a logging town, and a resort community...

 in the Great Smoky Mountains
Great Smoky Mountains
The Great Smoky Mountains are a mountain range rising along the Tennessee–North Carolina border in the southeastern United States. They are a subrange of the Appalachian Mountains, and form part of the Blue Ridge Physiographic Province. The range is sometimes called the Smoky Mountains or the...

 during the first weeks of June. Congaree National Park
Congaree National Park
Congaree National Park preserves the largest tract of old growth bottomland hardwood forest left in the United States. Located in South Carolina, the 26,546-acre national park received that designation in 2003 as the culmination of a grassroots campaign which had started in 1969...

 in South Carolina
South Carolina
South Carolina is a state in the Deep South of the United States that borders Georgia to the south, North Carolina to the north, and the Atlantic Ocean to the east. Originally part of the Province of Carolina, the Province of South Carolina was one of the 13 colonies that declared independence...

 is another host to this phenomenon.

Female Photuris fireflies are known for mimicking the mating flashes of other "lightning bugs" for the sole purpose of predation. Target males are attracted to what appears to be a suitable mate, and are then eaten. For this reason the Photuris species are sometimes referred to as "femme fatale
Femme fatale
A femme fatale is a mysterious and seductive woman whose charms ensnare her lovers in bonds of irresistible desire, often leading them into compromising, dangerous, and deadly situations. She is an archetype of literature and art...


Many fireflies do not produce light. Usually these species are diurnal, or day-flying, such as those in the genus Ellychnia. A few diurnal fireflies that inhabit primarily shadowy places, such as beneath tall plants or trees, are luminescent. One such genus is Lucidota.
These fireflies use pheromones to signal mates. This is supported by the fact that some basal groups do not show bioluminescence and, rather, use chemical signaling. Phosphaenus hemipterus has photic organs, yet is a diurnal firefly and displays large antennae and small eyes. These traits strongly suggests pheromones are used for sexual selection, while photic organs are used for warning signals. In controlled experiments, males coming from downwind arrived at females first, thus male arrival was correlated with wind direction, indicating males' chemotaxis into a pheromone plume. Males were also found to be able to find females without the use of visual cues, when the sides of test Petri dish
Petri dish
A Petri dish is a shallow glass or plastic cylindrical lidded dish that biologists use to culture cells or small moss plants. It was named after German bacteriologist Julius Richard Petri, who invented it when working as an assistant to Robert Koch...

es were covered with black tape. This and the facts that females do not light up at night and males are diurnal point to the conclusion that sexual communication in P. hemipterus is entirely based on pheromones.


Firefly systematics, as with many insects, are in a constant state of flux, as new species continue to be discovered. The five subfamilies listed above are the most commonly accepted ones, though others, such as the Amydetinae and Psilocladinae, have been proposed. This was mainly done in an attempt to revise the Lampyrinae
The Lampyrinae are a large subfamily of fireflies . The exact delimitation, and the internal systematics, are a matter of debate; for long this group was used as a "wastebin taxon" to hold any fireflies with insufficiently resolved relationships...

, which bit by bit had become something of a "wastebin taxon
Wastebin taxon
Wastebasket taxon is a term used in some taxonomic circles to refer to a taxon that has the sole purpose of classifying organisms that do not fit anywhere else. They are typically defined by their lack of one or more distinct character states or by their not belonging to one or more other taxa...

" to hold incertae sedis
Incertae sedis
, is a term used to define a taxonomic group where its broader relationships are unknown or undefined. Uncertainty at specific taxonomic levels is attributed by , , and similar terms.-Examples:*The fossil plant Paradinandra suecica could not be assigned to any...

species and genera of fireflies. Other changes have been proposed, such as merging the Ototetrinae
The Ototetrinae are a small and somewhat disputed subfamily in the firefly family . They are close to the Luciolinae in some respects, but do not glow or flash like the more advanced fireflies. Rather, they attract their partners with pheromones like many relatives of the firefly family...

 into the Luciolinae
The Luciolinae are among the largest subfamilies of fireflies . They seem to be all "flashing" fireflies...

, but the arrangement used here appears to be the most frequently seen and stable layout for the time being. Though most groups appear to be monophyletic, some (e.g., the tribe
Tribe (biology)
In biology, a tribe is a taxonomic rank between family and genus. It is sometimes subdivided into subtribes.Some examples include the tribes: Canini, Acalypheae, Hominini, Bombini, and Antidesmeae.-See also:* Biological classification* Rank...

The Photinini are a large tribe of fireflies in the subfamily Lampyrinae. Photinus pyralis is famous in biotechnology for its luciferase gene. This is sometimes employed as a marker gene; genetically modified organisms which contain it start to glow like the firefly when brought in contact with...

) are perhaps better divided.

There seem to be two groups of subfamilies: one containing many American
The Americas, or America , are lands in the Western hemisphere, also known as the New World. In English, the plural form the Americas is often used to refer to the landmasses of North America and South America with their associated islands and regions, while the singular form America is primarily...

 and some Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...

n species in the Lampyrinae and Photurinae, and one, predominantly Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

n, made up from the other subfamilies. While the subfamilies as understood here are, in general, monophyletic, there are still a few genera that need to be moved about for the subfamilies to accurately represent the evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...

ary relationships among the fireflies.

The Rhagophthalmidae
Rhagophthalmidae is a family of beetles within the larger Elateroidea group that include click-beetles. Members of this beetle family have bioluminescent organs on the larvae and are closely related to the Phengodidae and Lampyridae , and were often included in one of these families as a...

 are a glow worm
The beetle family Phengodidae is known also as glowworm beetles, whose larvae are known as glowworms. The females and larvae have bioluminescent organs. They occur throughout the New World from extreme southern Canada to Chile...

-like lineage of Elateroidea
Elateroidea is a large superfamily of beetles. It contains the familiar click beetles, fireflies, and soldier beetles, and their relatives.Certain clusters of families within the superfamily are more strongly related to one another; for example, the Elateridae has close ties to Anischiidae,...

. They have in the recent past usually been considered a distinct family, but it is still disputed as to whether this is correct. Indeed, they might be the only close relative of the puzzling firefly genus Pterotus, which sometimes is placed in a monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...


The genus Phausis
Phausis is a genus of firefly beetles . These beetles are for the most part unimpressive in their appearance and behaviour, and thus have not drawn much study, and little is known about many of the species. Species in this genus are at least known from Europe and North America...

, usually placed in the tribe
Tribe (biology)
In biology, a tribe is a taxonomic rank between family and genus. It is sometimes subdivided into subtribes.Some examples include the tribes: Canini, Acalypheae, Hominini, Bombini, and Antidesmeae.-See also:* Biological classification* Rank...

The Photinini are a large tribe of fireflies in the subfamily Lampyrinae. Photinus pyralis is famous in biotechnology for its luciferase gene. This is sometimes employed as a marker gene; genetically modified organisms which contain it start to glow like the firefly when brought in contact with...

of the Lampyrinae, might represent another rather distinct lineage instead.

External links

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