Firefly

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For other uses, see Firefly (disambiguation).

Fireflies
Lampyris noctiluca
Scientific classification
Kingdom: Animalia Phylum: Arthropoda Class: Insecta Order: Coleoptera Suborder: Polyphaga Infraorder: Elateriformia Superfamily: Elateroidea Family: Lampyridae Latreille, 1817
Genera
Curtos Cyphonocerus Drilaster Ellychnia Hotaria Lampyris Lucidina Lucidota Luciola - Japanese fireflies Phausis Photinus - common eastern firefly Photuris Pristolycus Pyractomena Pyrocoelia Stenocladius many others

Fireflies (family Lampyridae), also called lightning bugs, are luminous beetles. The names are used interchangably, in the northern United States, firefly is more common, while in the southern states, lightning bug is more common. The common names come from the fact that the adults of some species emit flashes of light to attract mates.

There are more than 2000 species of firefly, found in temperate and tropical environments around the world. Many species can be found in marshes or in wet, wooded areas where their larvae have an abundant source of food.

[edit] Biology

Scanning electron micrograph of a firefly

Fireflies tend to be soft-bodied, often with the elytra more leathery than in other beetles. They are small to medium sized, and some are colourful. Though the females of some species are similar in appearance to males, larviform females are found in many other firefly species. These females can often only be distinguished from the larvae because they have compound eyes.

The most commonly known fireflies are nocturnal, though there are numerous species that are diurnal. Most diurnal species are non-luminescent, though some species that remain in shadowy areas can produce light.

A few days after mating, which occurs in the spring, a female lays her fertilized eggs on or just below the surface of the ground. The eggs hatch 3-4 weeks later and the larva feed until the end of the summer. The larvae are commonly called glowworms, not to be confused with the distinct beetle family Phengodidae. Lampyrid larvae have simple eyes.

Fireflies overwinter (some species for several years) during the larval stage. 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 pupate for 1 to 2.5 weeks and emerge as adults.

The larvae of most species are specialized predators and feed on other larvae, terrestrial snails, and slugs. Some are so specialized that they have grooved mandibles, which deliver digestive fluids directly to their prey. The diet of adults is variable. It has been reported that some are predatory and some feed on plant pollen or nectar.

[edit] Light production

running lights on a meadow

Light production in fireflies is due to a chemical reaction that occurs in specialized light-emitting organs, usually on the lower abdomen. The enzyme luciferase acts on luciferin in this organ to stimulate light emission. This reaction is of scientific interest. Genes coding for these substances have been inserted into many different organisms (see “Applications” in Luciferase). Luciferase is also used in forensics, and the enzyme has medical uses.

The process of light production in fireflies is called lighting. Its function in the adult beetles is primarily to locate other individuals of the same species for reproduction. Many species, especially in the genus Photinus (genus), are distinguished by the unique courtship flash patterns emitted by flying males in search of females. Photinus females generally do not fly, but give a flash response to males of their own species.

Tropical fireflies, particularly in Southeast Asia (Thailand and Malaysia) routinely synchronize their flashes among large groups, a startling example of spontaneous biological order. This phenomenon occurs through the night along river banks in the Malaysian jungles every day of the year. It is significantly more rare in the Western hemisphere. Current hypotheses about the causes range from diet, social interaction and altitude. In the United States, one of the most famous sightings of fireflies blinking in unison occurs near Elkmont, Tennessee in the Great Smoky Mountains during the second week of June[1]. Congaree National Park in South Carolina is host to the phenomenon at points at or above 2,000 feet in elevation[2][3].

firefly larva

Female Photuris fireflies are known for mimicking the mating flashes of other fireflies 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 Photuris females are sometimes referred to as "femme fatale".

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 primarily inhabit shadowy places, such as beneath tall plants or trees, are luminescent. One such genus is Lucidota

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.

[edit] Fireflies and humans

The ancient Chinese sometimes captured fireflies in transparent or semi-transparent containers and used them as (short-term) lanterns.

The firefly is the state insect of Pennsylvania. At one point, Indiana seriously considered making the Say's Firefly the state insect, but the legislature never put the measure to a vote.

[edit] References

• Lampyridae (TSN 113835). Integrated Taxonomic Information System. Accessed on 30 April 2006.
• http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi
• http://www.iisc.ernet.in/academy/resonance/Sept2002/pdf/Sept2002p49-55.pdf
• Branham, M. A., and J. W. Wenzel. 2003. The origin of photic behavior and the evolution of sexual communication in fireflies (Coleoptera: Lampyridae). Cladistics 19: 1-22.
• Stous, Hollend. 1997. A review of predation in Photuris, and its effects on the evolution of flash signalling in other New World fireflies. http://www.colostate.edu/Depts/Entomology/courses/en507/papers_1997/stous.html

[edit] External links

• Firefly sighting reports
• Bioluminescence in insects
• Afterglow - Is it lights out for fireflies? (Failure magazine, June 2003)
• Firefly FAQs at http://www.byteland.org/naturalist/firefly_faq.html is a great resource based upon the original firefly studies of naturalist, Terry Lynch.
• Project Firefly Forum at http://projectfirefly.proboards98.com/ is an interactive forum for both students and professionals hosted by naturalist, Terry Lynch, to help promote education and exchange of information by nature lovers around the world who are interested in fireflies and bioluminescence in general.
• Save the Firefly at http://www.byteland.org/firefly/index.html focuses upon the need to help preserve and protect fireflies which have disappeared in many areas. Naturalist Terry Lynch presents an insight into the various factors which relate to the disappearance of fireflies and has established a promotional effort to contribute toward saving the firefly through providing education and information.
• Interactive Firefly-Simulation