Data related to
Black fly at Wikispecies
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. They are divided into two
Parasimuliinae contains only one genus and four species;
Simuliinae contains all the rest. Over 1,800 of the species belong to
the genus Simulium.
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).
2 Regional effects of black fly populations
3 Public health
3.1 River blindness
4 See also
8 External links
Eggs are laid in running water, and the larvae attach themselves to
rocks. Breeding success is highly sensitive to water pollution. 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.
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
Work conducted at
Portsmouth University in 1986–1987[citation
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 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.
Pennsylvania, in the United States, 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.
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. 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.
The New Zealand "sandflies" are actually black flies of the species
Austrosimulium australense and A. ungulatum.
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.
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. 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
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
Repellents provide some protection against biting flies. Products
containing the active ingredient
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
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.
Fly Song", a song by
Wade Hemsworth inspired by his
experiences with them and "Black Flies" by Bill Staines
Use of DNA in forensic entomology
^ a b Adler, Peter H.; Crosskey, Roger W. (2017). World blackflies
(Diptera: Simuliidae): a comprehensive revision of the taxonomic and
geographical inventory  (PDF). p. 11.
^ Daley, Beth (2008-06-23). "Black flies surge in Maine's clean
rivers". Boston Globe. Retrieved 2008-06-23.
^ The Canadian Encyclopedia: Black
Fly Archived September 30, 2007, at
the Wayback Machine.
^ "Black Fly". Depweb.state.pa.us. Retrieved 2012-02-15.
^ "Blandford's Most pernicious beast". Dorset Life. Retrieved 6
^ Hough, Andrew (2010-07-29). "Blandford fly: surge in 'infected'
insect bites blamed on new superfly". The Daily Telegraph.
^ "1. Sandflies: New Zealand's blackflies - Sandflies and mosquitoes -
Te Ara Encyclopedia of New Zealand". Teara.govt.nz. 2009-03-01.
^ Thompson, F. Christian (March 2001). "The Name of the Type Species
Simulium (Diptera: Simuliidae): an historical footnote".
Entomological News. 112 (2): 125. Retrieved 2011-04-08.
^ Mullen, Gary; Durden, Lance (2009). Medical and Veterinary
Entomology. Academic Press. ISBN 978-0-12-372500-4.
^ a b Service, MW (2008). Medical Entomology for Students. Cambridge
University Press. pp. 81–92. ISBN 978-0-521-70928-6.
Black Flies Fact Sheet from Ohio State University
Extensive Simuliidae (black fly) Web pages at blackfly.org.uk
Black fly species inventory
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.
Taxonomy and systematics of Simuliidae
Diptera.info Gallery Images
Extant Diptera families
Dixidae (meniscus midges)
Corethrellidae (frog-biting midges)
Chaoboridae (phantom midges)
Thaumaleidae (solitary midges)
Simuliidae (black flies)
Ceratopogonidae (biting midges)
Chironomidae (non-biting midges)
Blephariceridae (net-winged midges)
Deuterophlebiidae (mountain midges)
Bibionidae (march flies, lovebugs)
Anisopodidae (wood gnats)
Sciaridae (dark-winged fungus gnats)
Cecidomyiidae (gall midges)
Scatopsidae (minute black scavenger flies, or dung midges)
Psychodidae (moth flies)
Ptychopteridae (phantom crane flies)
Tanyderidae (primitive crane flies)
Trichoceridae (winter crane flies)
Pediciidae (hairy-eyed craneflies)
Tipulidae (crane flies)
Apioceridae (flower-loving flies)
Asilidae (robber flies)
Bombyliidae (bee flies)
Hilarimorphidae (hilarimorphid flies)
Mydidae (mydas flies)
Scenopinidae (window flies)
Therevidae (stiletto flies)
Hybotidae (dance flies)
Dolichopodidae (long-legged flies)
Empididae (dagger flies, balloon flies)
Acroceridae (small-headed flies)
Nemestrinidae (tangle-veined flies)
Phoridae (scuttle flies, coffin flies, humpbacked flies)
Opetiidae (flat-footed flies)
Ironomyiidae (ironic flies)
Lonchopteridae (spear-winged flies)
Platypezidae (flat-footed flies)
Pipunculidae (big-headed flies)
Conopidae (thick-headed flies)
Pallopteridae (flutter flies)
Piophilidae (cheese flies)
Platystomatidae (signal flies)
Tephritidae (peacock flies)
Ulidiidae (picture-winged flies)
Micropezidae (stilt-legged flies)
Neriidae (cactus flies, banana stalk flies)
Diopsidae (stalk-eyed flies)
Psilidae (rust flies)
Coelopidae (kelp flies)
Sepsidae (black scavenger flies)
Sciomyzidae (marsh flies)
Sphaeroceridae (small dung flies)
Celyphidae (beetle-backed flies)
Chamaemyiidae (aphid flies)
Agromyzidae (leaf miner flies)
Aulacigastridae (sap flies)
Clusiidae (lekking, or druid flies)
Neurochaetidae (upside-down flies)
Curtonotidae (quasimodo flies)
Diastatidae (bog flies)
Ephydridae (shore flies)
Drosophilidae (vinegar and fruit flies)
Braulidae (bee lice)
Canacidae (beach flies)
Chloropidae (frit flies)
Milichiidae (freeloader flies)
Lonchaeidae (lance flies)
Anthomyiidae (cabbage flies)
Fanniidae (little house flies)
Muscidae (house flies, stable flies)
Scathophagidae (dung flies)
Calliphoridae (blow-flies: bluebottles, greenbottles)
Mystacinobiidae (New Zealand batfly)
Sarcophagidae (flesh flies)
Tachinidae (tachina flies)
Glossinidae (tsetse flies)
Hippoboscidae (louse flies)
Mormotomyiidae (frightful hairy fly)
Nycteribiidae (bat flies)
Streblidae (bat flies)
Pantophthalmidae (timber flies)
Stratiomyidae (soldier flies)
Xylomyidae (wood soldier flies)
Rhagionidae (snipe flies)
Athericidae (water snipe flies)
Tabanidae (horse and deer flies)
Xylophagidae (awl flies)
List of families of Diptera
Fauna Europaea: 11646