Black fly

A black fly (sometimes called a buffalo gnat, turkey gnat, or white socks) is any member of the family Simuliidae of the Culicomorpha infraorder. They are related to the Ceratopogonidae, Chironomidae, and Thaumaleidae. Over 2,200 species of black flies have been formally named, of which 15 are extinct.[1] They are divided into two subfamilies: Parasimuliinae contains only one genus and four species; Simuliinae contains all the rest. Over 1,800 of the species belong to the genus Simulium.[1]

Most black flies gain nourishment by feeding on the blood of mammals, including humans, although the males feed mainly on nectar. They are usually small, black or gray, with short legs, and antennae. They are a common nuisance for humans, and many U.S. states have programs to suppress the black fly population. They spread several diseases, including river blindness in Africa (Simulium damnosum and S. neavei) and the Americas (S. callidum and S. metallicum in Central America, S. ochraceum in Central and South America).

Black fly
Simulium trifasciatum adult (British Entomology by John Curtis- 765)
Simulium trifasciatum
Scientific classification

Newman, 1834


Data related to Black fly at Wikispecies


Eggs are laid in running water, and the larvae attach themselves to rocks. Breeding success is highly sensitive to water pollution.[2] The larvae use tiny hooks at the ends of their abdomens to hold on to the substrate, using silk holdfasts and threads to move or hold their place. They have foldable fans surrounding their mouths. The fans expand when feeding, catching passing debris (small organic particles, algae, and bacteria). The larva scrapes the fan's catch into its mouth every few seconds. Black flies depend on lotic habitats to bring food to them. They will pupate under water and then emerge in a bubble of air as flying adults. They are often preyed upon by trout during emergence. The larva of some South African species are known to be phoretic on mayfly nymphs.

Black Fly
A female black fly

Adult males feed on nectar, while females exhibit anautogeny and feed on blood before laying eggs. Some species in Africa can range as far as 40 mi (64 km) from aquatic breeding sites in search of their blood meals, while other species have more limited ranges.

Different species prefer different host sources for their blood meals, which is sometimes reflected in the common name for the species. They feed in the daytime, preferably when wind speeds are low.

Black flies may be either univoltine or multivoltine, depending on the species. The number of generations a particular pest species has each year tends to correlate with the intensity of human efforts to control those pests.

Work conducted at Portsmouth University in 1986–1987 indicates Simulium spp. create highly acidic conditions within their midguts. This basic environment provides conditions ideally suited to bacteria that metabolise cellulose. Insects cannot metabolise cellulose independently, but the presence of these bacteria allow cellulose to be metabolised into basic sugars. This provides nutrition to the black fly larvae, as well as the bacteria. This symbiotic relationship indicates a specific adaptation, as fresh-flowing streams could not provide sufficient nutrition to the growing larva in any other way.

Regional effects of black fly populations

Black Fly Attack on theDubawnt River Nunavut
Black flies attack a canoe expedition in July 2015 in the Canadian Arctic, Dubawnt River, Nunavut.
  • In the wetter parts of the northern latitudes of North America, including parts of Canada, New England, Minnesota, and the Upper Peninsula of Michigan, black fly populations swell from late April to July, becoming a nuisance to humans engaging in common outdoor activities, such as gardening, boating, camping, and backpacking. They can also be a significant nuisance in mountainous areas.
  • Black flies are a scourge to livestock in Canada, causing weight loss in cattle and sometimes death.[3]
  • Pennsylvania operates the largest single black fly control program in North America. The program is seen as beneficial to both the quality of life for residents and to the state's tourism industry.[4]
  • The Blandford fly (Simulium posticatum) in England was once a public health problem in the area around Blandford Forum, Dorset, due to its large numbers and the painful lesions caused by its bite. It was eventually controlled by carefully targeted applications of Bacillus thuringiensis israelensis.[5] In 2010, a summer surge of insect bites blamed on the Blandford fly required many who had been bitten to be treated in a hospital.[6]
  • The New Zealand "sandflies" are actually black flies of the species Austrosimulium australense and A. ungulatum.[7]
  • In parts of Scotland, various species of black flies are a nuisance and bite humans, mainly between May and September. They are found mainly in mixed birch and juniper woodlands, and at lower levels in pine forests, moorlands, and pastures. Bites are most often found on the head, neck, and back. They also frequently land on legs and arms.

Public health

Only four genera in the family Simuliidae, Simulium, Prosimulium, Austrosimulium, and Cnephia, contain species that feed on people, though other species prefer to feed on other mammals or on birds. Simulium, the type genus, is the most widespread and is a vector for several diseases, including river blindness.

Mature adults can disperse tens or hundreds of kilometers from their breeding grounds in fresh flowing water, under their own power and assisted by prevailing winds, complicating control efforts. Swarming behavior can make outdoor activities unpleasant or intolerable, and can affect livestock production. During the 18th century, the "Golubatz fly" (Simulium colombaschense) was a notorious pest in central Europe.[8] Even non-biting clouds of black flies, whether composed of males or of species that do not feed on humans or do not require a blood meal before egg laying, can form a nuisance by swarming into orifices.

Bites are shallow and accomplished by first stretching the skin using teeth on the labrum and then abrading it with the maxillae and mandibles, cutting the skin and rupturing its fine capillaries. Feeding is facilitated by a powerful anticoagulant in the flies' saliva, which also partially numbs the site of the bite, reducing the host's awareness of being bitten and thereby extending the flies' feeding time. Biting flies feed during daylight hours only and tend to zero in on areas of thinner skin, such as the nape of the neck or ears and ankles.

Itching and localized swelling and inflammation sometimes result from a bite. Swelling can be quite pronounced depending on the species and the individual's immune response, and irritation may persist for weeks. Intense feeding can cause "black fly fever", with headache, nausea, fever, swollen lymph nodes, and aching joints; these symptoms are probably a reaction to a compound from the flies' salivary glands. Less common severe allergic reactions may require hospitalization.[9][10]

Repellents provide some protection against biting flies. Products containing the active ingredient ethyl butylacetylaminopropionate (IR3535), DEET (N,N-diethyl-meta-toluamide), or picaridin are most effective. However, given the limited effectiveness of repellents, protecting oneself against biting flies requires taking additional measures, such as avoiding areas inhabited by the flies, avoiding peak biting times, and wearing heavy-duty, light-colored clothing, including long-sleeve shirts, long pants and hats. When black flies, for example, are numerous and unavoidable, netting that covers the head, like the “bee bonnets” used by beekeepers, can provide protection.[11]

River blindness

Black flies are central to the transmission of the parasitic nematode Onchocerca volvulus which causes onchocerciasis, or "river blindness". It serves as the larval host for the nematode and acts as the vector by which the disease is spread. The parasite lives on human skin and is transmitted to the black fly during feeding.[10]

See also


  1. ^ a b Adler, Peter H.; Crosskey, Roger W. (2017). World blackflies (Diptera: Simuliidae): a comprehensive revision of the taxonomic and geographical inventory [2017] (PDF). p. 11.
  2. ^ Daley, Beth (2008-06-23). "Black flies surge in Maine's clean rivers". Boston Globe. Retrieved 2008-06-23.
  3. ^ The Canadian Encyclopedia: Black Fly Archived September 30, 2007, at the Wayback Machine
  4. ^ "Black Fly". Retrieved 2018-05-21.
  5. ^ "Blandford's Most pernicious beast". Dorset Life. Retrieved 6 September 2016.
  6. ^ Hough, Andrew (2010-07-29). "Blandford fly: surge in 'infected' insect bites blamed on new superfly". The Daily Telegraph. London.
  7. ^ "1. Sandflies: New Zealand's blackflies - Sandflies and mosquitoes - Te Ara Encyclopedia of New Zealand". 2009-03-01. Retrieved 2012-02-15.
  8. ^ Thompson, F. Christian (March 2001). "The Name of the Type Species of Simulium (Diptera: Simuliidae): an historical footnote". Entomological News. 112 (2): 125. Retrieved 2011-04-08.
  9. ^ Mullen, Gary; Durden, Lance (2009). Medical and Veterinary Entomology. Academic Press. ISBN 978-0-12-372500-4.
  10. ^ a b Service, MW (2008). Medical Entomology for Students. Cambridge University Press. pp. 81–92. ISBN 978-0-521-70928-6.
  11. ^ "Biting Flies".



  • Kurtak, D. C. 1973. Observations on filter feeding by the larvae of black flies. PhD thesis. Cornell Univ., Ithaca. 157 pp.
  • Kurtak, D. C. 1978. Efficiency of filter feeding of black fly larvae. Can. J. ZooL 56:1608-23 110.

External links

Abitibi River

The Abitibi River is a river in northeastern Ontario, Canada, which flows northwest from Lake Abitibi to join the Moose River which empties into James Bay. This river is 540 kilometres (340 mi) long, and descends 265 metres (869 ft).The river was an important fur trading route for the Hudson's Bay Company. Now, pulp and paper, centered on the town of Iroquois Falls, Ontario, is an important industry in the heavily forested region through which it flows. The region also supports tourism and gold mining.The Abitibi Canyon Generating Station is located on the river at Abitibi Canyon. The experience of surveying the river for the purposes of building this plant was the inspiration for folk singer Wade Hemsworth's "The Black Fly Song".

The name is from the Algonquin words abitah, meaning middle and nipi meaning water.


Blackfly, black-fly, or black fly may refer to:

Black fly, a fly of the family Simuliidae

Blackfly (TV series), a 2001 Canadian comedy series

Blackfly (film), a 1991 animated short based on the Wade Hemsworth song

Black bean aphid (Aphis fabae)

Opener BlackFly, an electric ultralight aircraft design

David Rees (rugby union)

David Rees (born 15 October 1974) is a former Bristol Rugby player, currently playing for Clifton, who gained 11 caps for England between 1997 and 1999, scoring three tries.

Sale where he was first selected to play for England. Fourth cap on 6 December 1997 at Twickenham when facing legendary Jonah Lomu. With about 5 minutes gone, New Zealand won a penalty in their own 22. The All black fly-half Andrew Mehrtens kicked cross-field and found Rees on his right wing. Rees counter-attacked, chipped over the head of Lomu. He collected the ball, sidestepped round Zinzan Brooke's cover tackle and scored in the corner. The try sparked England on to a 23-9 half-time lead, though the All Blacks fought back in the second half with the match ending in a 26-26 draw.

He also scored two tries against Wales in a 1998 Five Nations Championship game.In 1999 he moved to Bristol, and moved to Leeds Tykes in 2003 after Bristol were relegated. Later, in 2006, he moved to Newbury R.F.C. In the 2008-2009 season he joined Clifton where he is still playing.

Degree day

A degree day is a measure of heating or cooling. Total degree days from an appropriate starting date are used to plan the planting of crops and management of pests and pest control timing. Weekly or monthly degree-day figures may also be used within an energy monitoring and targeting scheme to monitor the heating and cooling costs of climate controlled buildings, while annual figures can be used for estimating future costs.

A degree day is computed as the integral of a function of time that generally varies with temperature. The function is truncated to upper and lower limits that vary by organism, or to limits that are appropriate for climate control. The function can be estimated or measured by one of the following methods, in each case by reference to a chosen base temperature:

Frequent measurements and continuously integrating the temperature deficit or excess;

Treating each day's temperature profile as a sine wave with amplitude equal to the day's temperature variation, measured from max and min, and totalling the daily results;

As above, but calculating the daily difference between mean temperature and base temperature;

As previous, but with modified formulae on days when the max and min straddle the base temperature.A zero degree-day in energy monitoring and targeting is when either heating or cooling consumption is at a minimum, which is useful with power utility companies in predicting seasonal low points in energy demand.

Heating degree days are typical indicators of household energy consumption for space heating. The air temperature in a building is on average 2–3 °C (4–5 °F) higher than that of the air outside. A temperature of 18 °C (64 °F) indoors corresponds to an outside temperature of about 15.5 °C (60 °F). If the air temperature outside is below 15.5 °C, then heating is required to maintain a temperature of about 18 °C. If the outside temperature is 1 °C (1.8 °F) below the average temperature it is accounted as 1 degree-day. The sum of the degree days over periods such as a month or an entire heating season is used in calculating the amount of heating required for a building. Degree Days are also used to estimate air conditioning usage during the warm season.

Density dependence

In population ecology, density-dependent processes occur when population growth rates are regulated by the density of a population. This article will focus on density-dependence in the context of macroparasite life cycles.


A gnat is any of many species of tiny flying insects in the dipterid suborder Nematocera, especially those in the families Mycetophilidae, Anisopodidae and Sciaridae. They can be both biting and non-biting. Most often they fly in large numbers, called clouds. "Gnat" is a loose descriptive category rather than a phylogenetic or other technical term, so there is no scientific consensus on what constitutes a gnat.

Some entomologists consider only non-biting flies to be gnats. Certain universities also distinguish eye gnats: the Smithsonian Institution describes them as "non-biting flies, no bigger than a few grains of salt, ... attracted to fluids secreted by your eyes".

Lazlo Bane

Lazlo Bane is an alternative rock band from Santa Monica, California, United States. They are well known for collaborating with former Men at Work member Colin Hay, and providing the song "Superman" as the theme for the television show Scrubs.


Leucocytozoon (or Leukocytozoon) is a genus of parasitic alveolates belonging to the phylum Apicomplexa.

The species of this genus use blackflies (Simulium species) as their definitive host and birds as their intermediate host. There are over 100 species in this genus. Over 100 species of birds have been recorded as hosts to these parasites.

Little Red Boots

Little Red Boots is a studio album by Lindi Ortega, released in 2011. Music videos were shot for "Little Lie" (June 2011) and "Black Fly" (October 2011).

Lufttransport Staffel 6

The Lufttransport Staffel 6 (LT St6 or LT 6) is a transport squadron of the Swiss Air Force. The pilots associated with it are part of the Berufsfliegerkorps. A third of the pilots are militia pilots employed by civilian employers. The Lufttransport Staffel 6 together with the Lufttransport Staffel 8 is part of the Lufttransport Geschwader 2, which belongs to the Flugplatzkommando 2 (airfield command 2) at Alpnach Air Base. The unit's home base is Alpnach Air Base.

Lufttransport Staffel 6 carries as coat of arms an oval badge with the front view of a black fly on a white ground, above and below a red area. The abbreviation "LT" stands at the top in the red area, the number 6 is at the bottom. The camouflage version of the coat of arms shows the same image, but in dark green shades instead of white and red.

Metal Black (video game)

Metal Black is a shoot 'em up arcade video game developed and originally released by Taito in Japan on September 1991. The game was produced under the working title "Project Gun Frontier 2"; it was developed by the team behind Gun Frontier, including the game designer Takatsuna Senba, although its actual connection to Gun Frontier is very loose.

Players control the Black Fly on their mission to defeat the forces of Nemesis in hopes of saving the human race. Players collect many small power-ups to build their weapon's power; they can then unleash a large beam attack that drains said power level back to zero. Bosses can also collect these power-ups and use similar beam attacks. When a player's beam collides with a that of a boss, it culminates in a spectacular reaction, the more powerful attack pushing the weaker one aside.


Midge is a term used to refer to many species of small flies. The term "midge" does not define any particular taxonomic group, but includes species in several families of non-mosquito Nematoceran Diptera. They are found (seasonally or otherwise) on practically every land area outside permanently arid deserts and the frigid zones. Some midges, such as many Phlebotominae (sand fly) and Simuliidae (black fly), are vectors of various diseases. Many others play useful roles as prey items for insectivores, such as various frogs and swallows. Others are important as detritivores, participating in various nutrient cycles. The habits of midges vary greatly from species to species, though within any particular family, midges commonly have similar ecological roles.

Examples of families that include species of midges include:

Blephariceridae, net-winged midges

Cecidomyiidae, gall midges

Ceratopogonidae, biting midges (also known as no-see-ums or punkies in North America, and sandflies in Australia)

Chaoboridae, phantom midges

Chironomidae, non-biting midges (also known as muckleheads or muffleheads in the Great Lakes region of North America)

Deuterophlebiidae, mountain midges

Dixidae, meniscus midges

Scatopsidae, dung midges

Theumaleidae, solitary midges


Onchocerciasis, also known as river blindness, is a disease caused by infection with the parasitic worm Onchocerca volvulus. Symptoms include severe itching, bumps under the skin, and blindness. It is the second-most common cause of blindness due to infection, after trachoma.The parasite worm is spread by the bites of a black fly of the Simulium type. Usually, many bites are required before infection occurs. These flies live near rivers, hence the common name of the disease. Once inside a person, the worms create larvae that make their way out to the skin, where they can infect the next black fly that bites the person. There are a number of ways to make the diagnosis, including: placing a biopsy of the skin in normal saline and watching for the larva to come out, looking in the eye for larvae, and looking within the bumps under the skin for adult worms.A vaccine against the disease does not exist. Prevention is by avoiding being bitten by flies. This may include the use of insect repellent and proper clothing. Other efforts include those to decrease the fly population by spraying insecticides. Efforts to eradicate the disease by treating entire groups of people twice a year are ongoing in a number of areas of the world. Treatment of those infected is with the medication ivermectin every six to twelve months. This treatment kills the larvae but not the adult worms. The antibiotic doxycycline weakens the worms by killing an associated bacterium called Wolbachia, and is recommended by some as well. The lumps under the skin may also be removed by surgery.About 15.5 million people are infected with river blindness. Approximately 0.8 million have some amount of loss of vision from the infection. Most infections occur in sub-Saharan Africa, although cases have also been reported in Yemen and isolated areas of Central and South America. In 1915, the physician Rodolfo Robles first linked the worm to eye disease. It is listed by the World Health Organization (WHO) as a neglected tropical disease.

Opener BlackFly

The Opener BlackFly is an American electric-powered VTOL ultralight aircraft designed by Canadian Marcus Leng and under development by his company, Opener, Inc of Palo Alto, California. It was publicly introduced on 12 July 2018, after nine years of development. The aircraft is intended to be supplied complete and ready-to-fly.The manufacturer claims that the design is the world's first ultralight fixed-wing, all-electric, vertical take-off and landing aircraft. Investors in the company include Google co-founder Larry Page.


Sandfly (or sand fly) is a colloquial name for any species or genus of flying, biting, blood-sucking dipteran (fly) encountered in sandy areas. In the United States, sandfly may refer to certain horse flies that are also known as "greenheads" (family Tabanidae), or to members of the family Ceratopogonidae, also known in Florida and elsewhere as a sand gnat, sandflea, granny nipper, chitra, punkie, or punky. Outside the United States, sandfly may refer to members of the subfamily Phlebotominae within the Psychodidae. Biting midges (Ceratopogonidae) are sometimes called sand flies or no-see-ums (no-see-em, noseeum). New Zealand sandflies are in the genus Austrosimulium, a type of black fly.In the various sorts of sandfly only the female is responsible for biting and sucking the blood of mammals, reptiles and birds; the protein in the blood is necessary for the production of eggs, making the sandfly an anautogenous reproducer.

Some sandfly genera of the subfamily Phlebotominae are the primary vectors of leishmaniasis and pappataci fever; both diseases are confusingly referred to as sandfly fever. In the New World, leishmaniasis is spread by sand flies of the genus Lutzomyia; in the Old World, the disease is spread by sandflies of the genus Phlebotomus. Belize and Honduras are notorious in the Caribbean for their sandfly populations and travel pages frequently warn tourists to bring bug spray containing high concentrations of DEET.


Simulium is a genus of black flies, which may transmit diseases such as onchocerciasis (river blindness). It is a large genus with several hundred species, and 41 subgenera.The flies are pool feeders. Their saliva, which contains anticoagulants, a number of enzymes and histamine, is mixed with the blood, preventing clotting until it is ingested by the fly. These bites cause localized tissue damage, and if the number of feeding flies is sufficient, their feeding may produce a blood-loss anaemia.

The host's reaction to fly attacks may include systemic illness, allergic reactions or even death, presumably mediated by histamine. In humans, this systemic reaction is known as "black fly fever" and is characterized by headaches, fever, nausea, adenitis, generalized dermatitis, and allergic asthma.


Temefos or temephos (trade name Abate) is an organophosphate larvicide used to treat water infested with disease-carrying insects including mosquitoes, midges, and black fly larvae.

As with other organophosphates, temephos affects the central nervous system through inhibition of cholinesterase. In larvae, this results in death before reaching the adult stage.

In the developing world where the vector-borne disease dengue fever is endemic, temephos is widely used and applied by both private and public pest control in areas of standing water where the Aedes aegypti mosquito breeds in order to reduce the population of this disease-carrying insect. Temephos is also used in the Guinea worm eradication program to kill water fleas that carry guinea worm larvae.

Resistance to temephos by A. aegypti has been seen in Brazil. The Brazilian Aedes aegypti resistance monitoring program detected temephos resistance in A. aegypti populations from several localities in the country in 1999 (Funasa 2000, Lima et al. 2003). In 1999, mosquitoes from the city of Rio de Janeiro were already resistant to temephos.

The Black Fly Song

"The Black Fly Song" is a song by Wade Hemsworth, written in 1949, about being tormented by black flies while working in the wilds of Northern Ontario. It is an enduring classic of Canadian folk music, covered by a variety of other artists. A new version of the song (with accompanying vocals by Kate & Anna McGarrigle) which had a completely different tempo than the original, was made into an animated short film entitled Blackfly by Christopher Hinton and the National Film Board in 1991, and was nominated for Best Animated Short Film at the 64th Academy Awards in 1992.

Wade Hemsworth

Albert Wade Hemsworth (23 October 1916 – 19 January 2002) was a Canadian folk singer and songwriter. Although he was not a prolific composer, having written only about 20 songs during his entire career, several of his songs — most notably "The Wild Goose", "The Black Fly Song" and "The Log Driver's Waltz" — are among the most enduring classics in the history of Canadian folk music.

Extant Diptera families


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