Horse-fly
Encyclopedia
Insects in the order Diptera
, family Tabanidae, are commonly called horse flies. Often considered pests for the bites that many inflict, they are among the world's largest true flies
. They are known to be extremely noisy during flight. They are also important pollinators of flowers, especially in South Africa
. Tabanids occur worldwide, being absent only at extreme northern and southern latitudes. Flies of this type are among those known sometimes as gadflies, breeze flies, zimb
s or clegs. In Australia, they are known as "March Flies". In some areas of Canada, they are also known as Bull Dog Flies. Elsewhere the term "horse fly" refers to the unrelated dipteran family Bibionidae
.
There are approximately 4,500 species of horse flies known worldwide, over 1000 of which are in the genus Tabanus
. Three subfamilies are widely recognised:
Two well-known types are the common horse flies, genus
Tabanus Linnaeus
, 1758 and the deer flies, genus Chrysops Meigen
, 1802 are also known as banded horse flies because of their coloring. Both these genera give their names to subfamilies. The "Blue Tail Fly
" in the eponymous song was probably a tabanid common to the southeastern United States.
) for blood feeding. Most female horse flies feed on mammal blood, but some species are known to feed on birds, amphibians or reptiles. Immature or larva
l horse flies are fossorial
predators of other invertebrates in moist environments.
) species of horse flies use their knife-like mandibles to rip and/or slice flesh apart. Flies with longer proboscides bite more like a mosquito, their stylet-like mouthparts piercing the host's skin like needles.
The horsefly's modus operandi
is less secretive than that of its mosquito
counterparts, although it still aims to escape before their victim becomes conscious
of the pain signals. Moreover, the pain of a horsefly bite may mean that the victim is more concerned with assessing the wound, and not swatting the interloper. In any case defense is difficult, considering the agile nature of the fly. The bites may become itchy, sometimes causing a large swelling afterward if not treated quickly.
that preferentially attacks horse flies.
e fall into water or moist earth, feeding voraciously on invertebrates, such as snails, earthworms and other insects.
s of animals and humans. Tabanids are very good vectors of the equine infectious anaemia virus
, as well as some Trypanosome
species. Species in the genus Chrysops are biological vectors of Loa loa
, transmitting this parasitic filarial worm
between humans. They have also been known to transmit anthrax
among cattle and sheep and tularemia
between rabbits and humans.
Blood loss is a common problem in some animals, when large flies are abundant. Some animals have been known to lose up to 300 ml of blood in a single day from tabanid bites, which can severely weaken or even kill them.
Diptera
Diptera , or true flies, is the order of insects possessing only a single pair of wings on the mesothorax; the metathorax bears a pair of drumstick like structures called the halteres, the remnants of the hind wings. It is a large order, containing an estimated 240,000 species, although under half...
, family Tabanidae, are commonly called horse flies. Often considered pests for the bites that many inflict, they are among the world's largest true flies
Fly
True flies are insects of the order Diptera . They possess a pair of wings on the mesothorax and a pair of halteres, derived from the hind wings, on the metathorax...
. They are known to be extremely noisy during flight. They are also important pollinators of flowers, especially in South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
. Tabanids occur worldwide, being absent only at extreme northern and southern latitudes. Flies of this type are among those known sometimes as gadflies, breeze flies, zimb
Zimb
The zimb, also known as or , is any horse-fly of the genus Pangonia found in Ethiopia. The genus is more widespread and contains many species, but only those from this region are given the name "zimb". They are similar in feeding habits to the tsetse fly but completely unrelated...
s or clegs. In Australia, they are known as "March Flies". In some areas of Canada, they are also known as Bull Dog Flies. Elsewhere the term "horse fly" refers to the unrelated dipteran family Bibionidae
Bibionidae
Bibionidae is a family of flies . Approximately 650-700 species are known worldwide.-Biology:...
.
There are approximately 4,500 species of horse flies known worldwide, over 1000 of which are in the genus Tabanus
Tabanus
Tabanus is a genus of biting horseflies of the family Tabanidae. Females have scissor-like mouthparts that aim to cut the skin. The horsefly can then lap up the blood. Horseflies of this genus are known to be potential vectors of anthrax, worms and trypanosomes. Some species, such as Tabanus...
. Three subfamilies are widely recognised:
- Chrysopsinae
- Pangoniinae
- Tabaninae
- the genus Zophina is of uncertain placement, though it has been classified among the Pangoniinae.
Two well-known types are the common horse flies, genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Tabanus Linnaeus
Carolus Linnaeus
Carl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
, 1758 and the deer flies, genus Chrysops Meigen
Johann Wilhelm Meigen
Johann Wilhelm Meigen was a German entomologist famous for his pioneering work on Diptera.-Early years:Meigen was born in Solingen, the fifth of eight children of Johann Clemens Meigen and Sibylla Margaretha Bick. His parents, though not poor, were not wealthy either. The ran a small shop in...
, 1802 are also known as banded horse flies because of their coloring. Both these genera give their names to subfamilies. The "Blue Tail Fly
Blue Tail Fly
"Blue Tail Fly", "De Blue Tail Fly", or "Jimmy Crack Corn" is thought to be a blackface minstrel song, first performed in the United States in the 1840s that remains a popular children's song today....
" in the eponymous song was probably a tabanid common to the southeastern United States.
Diet
Adult horse flies feed on nectar and sometimes pollen. Females usually require a blood meal for reproduction. Males lack the necessary mouth parts (mandiblesMandible (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...
) for blood feeding. Most female horse flies feed on mammal blood, but some species are known to feed on birds, amphibians or reptiles. Immature or larva
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...
l horse flies are fossorial
Fossorial
A fossorial organism is one that is adapted to digging and life underground such as the badger, the naked mole rat, and the mole salamanders Ambystomatidae...
predators of other invertebrates in moist environments.
Biting behaviour
The bite from a large specimen is painful. Most short tongued (short proboscidProboscis
A proboscis is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In simpler terms, a proboscis is the straw-like mouth found in several varieties of species.-Etymology:...
) species of horse flies use their knife-like mandibles to rip and/or slice flesh apart. Flies with longer proboscides bite more like a mosquito, their stylet-like mouthparts piercing the host's skin like needles.
The horsefly's modus operandi
Modus operandi
Modus operandi is a Latin phrase, approximately translated as "mode of operation". The term is used to describe someone's habits or manner of working, their method of operating or functioning...
is less secretive than that of its mosquito
Mosquito
Mosquitoes are members of a family of nematocerid flies: the Culicidae . The word Mosquito is from the Spanish and Portuguese for little fly...
counterparts, although it still aims to escape before their victim becomes conscious
Consciousness
Consciousness is a term that refers to the relationship between the mind and the world with which it interacts. It has been defined as: subjectivity, awareness, the ability to experience or to feel, wakefulness, having a sense of selfhood, and the executive control system of the mind...
of the pain signals. Moreover, the pain of a horsefly bite may mean that the victim is more concerned with assessing the wound, and not swatting the interloper. In any case defense is difficult, considering the agile nature of the fly. The bites may become itchy, sometimes causing a large swelling afterward if not treated quickly.
Predators
Aside from generalized predators such as birds, there are also specialist predators such as the Horse guard wasp, a type of Sand waspSand wasp
The Bembicini, or Sand wasps, are a large tribe of crabronid wasps, comprising 20 genera. Bembicines are predators on various groups of insects. The type of prey captured tends to be rather consistent within each genus, with flies being the most common type of prey taken...
that preferentially attacks horse flies.
Reproduction
Eggs are laid on stones or vegetation usually close to water. On hatching, the larvaLarva
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 fall into water or moist earth, feeding voraciously on invertebrates, such as snails, earthworms and other insects.
Diseases
Tabanids are known vectors for some blood-borne diseaseBlood-borne disease
A blood-borne disease is one that can be spread through contamination by blood.The most common examples are HIV, hepatitis B, hepatitis C and viral hemorrhagic fevers....
s of animals and humans. Tabanids are very good vectors of the equine infectious anaemia virus
Equine infectious anemia
Equine infectious anemia or equine infectious anaemia , also known by horsemen as swamp fever, is a horse disease caused by a retrovirus and transmitted by bloodsucking insects. The virus is endemic in the Americas, parts of Europe, the Middle and Far East, Russia, and South Africa. The virus is a...
, as well as some Trypanosome
Trypanosoma
Trypanosoma is a genus of kinetoplastids , a monophyletic group of unicellular parasitic flagellate protozoa. The name is derived from the Greek trypano and soma because of their corkscrew-like motion. All trypanosomes are heteroxenous and are transmitted via a vector...
species. Species in the genus Chrysops are biological vectors of Loa loa
Loa loa
Loa loa is the filarial nematode species that causes Loa loa filariasis. It is commonly known as the "eye worm". Its geographic distribution includes Africa and India....
, transmitting this parasitic filarial worm
Filariasis
Filariasis is a parasitic disease and is considered an infectious tropical disease, that is caused by thread-like nematodes belonging to the superfamily Filarioidea, also known as "filariae"....
between humans. They have also been known to transmit anthrax
Anthrax
Anthrax is an acute disease caused by the bacterium Bacillus anthracis. Most forms of the disease are lethal, and it affects both humans and other animals...
among cattle and sheep and tularemia
Tularemia
Tularemia is a serious infectious disease caused by the bacterium Francisella tularensis. A Gram-negative, nonmotile coccobacillus, the bacterium has several subspecies with varying degrees of virulence. The most important of those is F...
between rabbits and humans.
Blood loss is a common problem in some animals, when large flies are abundant. Some animals have been known to lose up to 300 ml of blood in a single day from tabanid bites, which can severely weaken or even kill them.
See also
- Deer flyDeer flyDeer flies are flies in the genus Chrysops of the family Tabanidae that can be pests to cattle, horses, and humans. A distinguishing characteristic of a deer fly is patterned gold or green eyes....
- List of soldierflies and allies of Great Britain
- Use of DNA in forensic entomologyUse of DNA in forensic entomologyForensic entomology contains three aspects: medicocriminal entomology, urban entomology, and stored product entomology. This article focuses more on the medicocriminal aspect and how DNA is analyzed with various blood feeding insects.- Blood meal extraction :...
External links
- Horsefly Tabanus sp. diagnostic photographs
- Virtual Field Guide Tabanidae Images
- Family description and images
- Chrysops, Diachlorus, and Tabanus spp. on the UFUniversity of FloridaThe University of Florida is an American public land-grant, sea-grant, and space-grant research university located on a campus in Gainesville, Florida. The university traces its historical origins to 1853, and has operated continuously on its present Gainesville campus since September 1906...
/ IFASInstitute of Food and Agricultural SciencesThe University of Florida’s Institute of Food and Agricultural Sciences is a federal-state-county partnership dedicated to developing knowledge in agriculture, human and natural resources, and the life sciences, and enhancing and sustaining the quality of human life by making that information...
Featured Creatures Web site - Diachlorus ferrugatus, yellow fly on the UFUniversity of FloridaThe University of Florida is an American public land-grant, sea-grant, and space-grant research university located on a campus in Gainesville, Florida. The university traces its historical origins to 1853, and has operated continuously on its present Gainesville campus since September 1906...
/ IFASInstitute of Food and Agricultural SciencesThe University of Florida’s Institute of Food and Agricultural Sciences is a federal-state-county partnership dedicated to developing knowledge in agriculture, human and natural resources, and the life sciences, and enhancing and sustaining the quality of human life by making that information...
Featured Creatures Web site