Botfly | |
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Deer botfly Cephenemyia stimulator | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Diptera |
(unranked): | Eremoneura |
(unranked): | Cyclorrhapha |
Section: | Schizophora |
Subsection: | Calyptratae |
Superfamily: | Oestroidea |
Family: | Oestridae Leach, 1815 |
Subfamilies | |
Botflies, also known as warble flies, heel flies, and gadflies, are a family of flies known as the Oestridae. Their larvae are internal parasites of mammals, some species growing in the host's flesh and others within the gut. Dermatobia hominis is the only species of botfly known to parasitize humans routinely, though other species of flies cause myiasis in humans.
A botfly, [1] also written bot fly, [2] bott fly [3] or bot-fly [4] in various combinations, is any fly in the family Oestridae. Their life cycles vary greatly according to species, but the larvae of all species are internal parasites of mammals. Largely according to species, they also are known variously as warble flies, heel flies, and gadflies. The larvae of some species grow in the flesh of their hosts, while others grow within the hosts' alimentary tracts.
The word "bot" in this sense means a maggot. [4] A warble is a skin lump or callus such as might be caused by an ill-fitting harness, or by the presence of a warble fly maggot under the skin. The human botfly, Dermatobia hominis, is the only species of botfly whose larvae ordinarily parasitise humans, though flies in some other families episodically cause human myiasis and are sometimes more harmful.
The Oestridae now are generally defined as including the former families Oestridae, Cuterebridae, Gasterophilidae, and Hypodermatidae as subfamilies.
The Oestridae, in turn, are a family within the superfamily Oestroidea, together with the families Calliphoridae, Mesembrinellidae, Mystacinobiidae, Polleniidae, Rhiniidae, Rhinophoridae, Sarcophagidae, Tachinidae, and Ulurumyiidae.
Of families of flies causing myiasis, the Oestridae include the highest proportion of species whose larvae live as obligate parasites within the bodies of mammals. Roughly 150 species are known worldwide. [5] Most other species of flies implicated in myiasis are members of related families, such as blow-flies.
Botflies deposit eggs on a host, or sometimes use an intermediate vector such as the common housefly, mosquitoes, and, in the case of D. hominis, a species of tick. After mating, the female botfly captures the phoretic insect by holding onto its wings with her legs. She then makes the slip—attaching 15 to 30 eggs onto the insect or arachnid's abdomen, where they incubate. The fertilized female does this over and over again to distribute the 100 to 400 eggs she produces in her short adult stage of life of only 8–9 days. Larvae from these eggs, stimulated by the warmth and proximity of a large mammal host, drop onto its skin and burrow underneath. [6] Intermediate vectors are often used, since a number of animal hosts recognize the approach of a botfly and flee. [7]
Eggs are deposited on larger animals' skin directly, or the larvae hatch and drop from the eggs attached to the intermediate vector; the body heat of the host animal induces hatching upon contact or immediate proximity. Some forms of botfly also occur in the digestive tract after ingestion by licking.
Myiasis can be caused by larvae burrowing into the skin (or tissue lining) of the host animal. Mature larvae drop from the host and complete the pupal stage in soil. They do not kill the host animal, thus they are true parasites.
The equine botflies present seasonal difficulties to equestrian caretakers, as they lay eggs on the insides of horses' front legs on the cannon or metacarpal bone (below the knee) and knees, and sometimes on the throat or nose depending on the species. These eggs, which look like small, yellow drops of paint, must be carefully removed during the laying season (late summer and early fall) to prevent infestation in the horse. When a horse rubs its nose on its legs, the eggs are transferred to the mouth and from there to the intestines, where the larvae grow and attach themselves to the stomach lining or the small intestine. The attachment of the larvae to the tissue produces a mild irritation, which results in erosions and ulcerations at the site. [8] Removal of the eggs (which adhere to the host's hair) is difficult, since the bone and tendons are directly under the skin on the cannon bones; eggs must be removed with a sharp knife (often a razor blade) or rough sandpaper and caught before they reach the ground. The larvae remain attached and develop for 10–12 months before they are passed out in the feces. Occasionally, horse owners report seeing botfly larvae in horse manure. These larvae are cylindrical in shape and are reddish orange in color. In one to two months, adult botflies emerge from the developing larvae and the cycle repeats itself. [8] Botflies can be controlled with several types of dewormers, including dichlorvos, ivermectin, and trichlorfon.
In cattle, the lesions caused by these flies can become infected by Mannheimia granulomatis , a bacterium that causes lechiguana, characterized by rapid-growing, hard lumps beneath the skin of the animal. Without antibiotics, an affected animal will die within 3–11 months. [9] [10]
Philornis botflies often infest nestlings of wild parrots, like scarlet macaws [11] and hyacinth macaws. [12] A method using a reverse syringe design snake bite extractor proved to be suitable for removing larvae from the skin. [11]
Cuterebra fontinella , the mouse botfly, parasitizes small mammals all around North America. [13]
Dermatobia hominis , the human botfly, occasionally uses humans to host its larvae. [14]
In cold climates supporting reindeer or caribou-reliant populations, large quantities of Hypoderma tarandi (caribou warble fly) maggots are available to human populations during the butchery of animals. [15]
The sixth episode of season one of the television series Beyond Survival , titled "The Inuit – Survivors of the Future", features survival expert Les Stroud and two Inuit guides hunting caribou on the northern coast of Baffin Island near Pond Inlet, Nunavut, Canada. Upon skinning and butchering of one of the animals, numerous larvae (presumably H. tarandi, although not explicitly stated) are apparent on the inside of the caribou pelt. Stroud and his two Inuit guides eat (albeit somewhat reluctantly) one larva each, with Stroud commenting that the larva "tastes like milk" and was historically commonly consumed by the Inuit. [16]
Copious art dating back to the Pleistocene in Europe confirms their consumption in premodern times, as well. [17]
The Babylonian Talmud Hullin 67b discusses whether the warble fly is kosher. [18]
Gasterophilus, commonly known as botfly, is a genus of parasitic fly from the family Oestridae that affects different types of animals, especially horses, but it can also act on cows, sheep, and goats. A case has also been recorded in a human baby.
The apple maggot, also known as the railroad worm, is a species of fruit fly, and a pest of several types of fruits, especially apples. This species evolved about 150 years ago through a sympatric shift from the native host hawthorn to the domesticated apple species Malus domestica in the northeastern United States. This fly is believed to have been accidentally spread to the western United States from the endemic eastern United States region through contaminated apples at multiple points throughout the 20th century. The apple maggot uses Batesian mimicry as a method of defense, with coloration resembling that of the forelegs and pedipalps of a jumping spider.
Myiasis, also known as flystrike or fly strike, is the parasitic infestation of the body of a live animal by fly larvae (maggots) that grow inside the host while feeding on its tissue. Although flies are most commonly attracted to open wounds and urine- or feces-soaked fur, some species can create an infestation even on unbroken skin and have been known to use moist soil and non-myiatic flies as vector agents for their parasitic larvae.
Warble fly is a name given to the genus Hypoderma: large flies which are parasitic on cattle and deer. Other names include "heel flies", "bomb flies" and "gadflies", while their larvae are often called "cattle grubs" or "wolves." Common species of warble fly include Hypoderma bovis and Hypoderma lineatum and Hypoderma tarandi. Larvae of Hypoderma species also have been reported in horses, sheep, goats and humans. They have also been found on smaller mammals such as dogs, cats, squirrels, voles and rabbits.
The name deer botfly refers to any species in the genus Cephenemyia, within the family Oestridae. They are large, gray-brown flies, often very accurate mimics of bumblebees. They attack chiefly the nostrils and pharyngeal cavity of members of the deer family. The larva of Cephenemyia auribarbis, infesting the stag, is called a stagworm. The genus name comes from the Greek kēphēn, meaning 'drone bee', and myia, meaning 'fly'.
Cochliomyia hominivorax, the New World screwworm fly, or simply screwworm or screw-worm, is a species of parasitic fly that is well known for the way in which its larvae (maggots) eat the living tissue of warm-blooded animals. It is present in the New World tropics. There are five species of Cochliomyia but only one species of screwworm fly in the genus is parasitic; there is also a single Old World species in a different genus. Infestation of a live vertebrate animal by a maggot is technically called myiasis. While the maggots of many fly species eat dead flesh, and may occasionally infest an old and putrid wound, screwworm maggots are unusual because they attack healthy tissue.
The Cuterebrinae, the robust bot flies, are a subfamily of Oestridae which includes large, parasitic flies; this group has historically been treated as a family, but all recent classifications place them firmly within the Oestridae. Both genera spend their larval stages in the skin of mammals. The genus Cuterebra, or rodent bots, attack rodents and similar animals. The other genus, Dermatobia, attacks primates, including humans.
The human botfly, Dermatobia hominis, is a species of botfly whose larvae parasitise humans. It is also known as the torsalo or American warble fly, though the warble fly is in the genus Hypoderma and not Dermatobia, and is a parasite on cattle and deer instead of humans.
Cordylobia anthropophaga, the mango fly, tumbu fly, tumba fly, putzi fly, or skin maggot fly, is a species of blow-fly common in East and Central Africa. It is a parasite of large mammals during its larval stage. C. anthropophaga is found in the tropics of Africa and is a common cause of myiasis in humans in the region.
Entomological evidence is legal evidence in the form of insects or related artifacts and is a field of study in forensic entomology. Such evidence is used particularly in medicolegal and medicocriminal applications due to the consistency of insects and arthropods in detecting decomposition quickly. Insect evidence is customarily used to determine post-mortem interval (PMI) but can also be used as evidence of neglect or abuse. It can indicate how long a person was abused/neglected as well as provide important insights into the amount of bodily care given to the neglected or abused person.
Cephenemyia ulrichii or the moose botfly, also called the elk botfly, moose nose botfly or moose throat botfly, is a large botfly that resembles a bumblebee. In the wild, they attack chiefly the nostrils and pharyngeal cavity of moose, but have been found in other deer species. There have also been several cases of C. ulrichii squirting their larvae into the eyes of human beings, a somewhat painful event that requires medical attention to forestall any possibility of serious damage.
Hypoderma tarandi, also known as the reindeer warble fly and reindeer botfly, is a species of warble fly that is parasitic on reindeer.
Cephenemyia trompe, also known as the reindeer nose botfly, is a species of botfly first described by Adolph Modéer in 1786. It belongs to the deer botfly genus Cephenemyia. This fly is parasitic on reindeer. It is one of two Cephenemyia species found only in Scandinavia.
Many species of flies of the two-winged type, Order Diptera, such as mosquitoes, horse-flies, blow-flies and warble-flies, cause direct parasitic disease to domestic animals, and transmit organisms that cause diseases. These infestations and infections cause distress to companion animals, and in livestock industry the financial costs of these diseases are high. These problems occur wherever domestic animals are reared. This article provides an overview of parasitic flies from a veterinary perspective, with emphasis on the disease-causing relationships between these flies and their host animals. The article is organized following the taxonomic hierarchy of these flies in the phylum Arthropoda, order Insecta. Families and genera of dipteran flies are emphasized rather than many individual species. Disease caused by the feeding activity of the flies is described here under parasitic disease. Disease caused by small pathogenic organisms that pass from the flies to domestic animals is described here under transmitted organisms; prominent examples are provided from the many species.
Cuterebra fontinella, the mouse bot fly, is a species of New World skin bot fly in the family Oestridae. C. fontinella is typically around 1 cm (0.39 in) in length with a black and yellow color pattern. C. fontinella develops by parasitizing nutrients from its host, typically the white-footed mouse. C. fontinella has even been known to parasitize humans in rare cases. Individuals parasitized by C. fontinella will develop a large bump on the skin that is indicative of parasitization.
Cuterebra emasculator, the squirrel bot fly, is a species of new world skin bot fly in the family Oestridae. The species was first described by Asa Fitch in 1856. It is an internal parasite of chipmunks and tree squirrels in the eastern United States. The species' name comes from the belief that larvae ate the testicles of chipmunks. This belief is false, as parasitism by the larvae of these flies does not result in lower fertility - chipmunks mate in the spring, while botfly infections occur in the summer, and the larva do not impede sperm production as they reside below the skin.
Gasterophilus intestinalis, also known as horse bot fly, is a species of insect of the family Oestridae, and is found worldwide. The adults, which have a bumblebee-like appearance, are prominently active in the summer. G. intestinalis is primarily a parasite of horses, mules and donkeys.
Cuterebra cuniculi is a species of new world skin bot fly in the family Oestridae. Its range is restricted to the states of Georgia and Florida. Its larvae are parasites of the eastern cottontail and marsh rabbit.
Portschinskia is a genus of flies. They are also known as bumblebee bot flies due to their striking resemblance to bumblebees both in habit and colour patterns. Like all bot flies they are obligate parasites whose larvae develop in mammals.