Botfly

Botflies, also known as warble flies, heel flies, and gadflies, are a family of technically known as the Oestridae. Their e are internal parasites of mammals, some species growing in the host's flesh and others within the gut.  is the only species of botfly known to parasitize humans routinely, though other species of flies cause in humans.

General
A botfly, also written bot fly, bott fly or bot-fly in various combinations, is any in the  Oestridae. Their lifecycles vary greatly according to species, but the e of all species are internal parasites of mammals. Largely according to species, they also are known variously as, heel flies, and gadflies. The larvae of some species grow in the flesh of their hosts, while others grow within the hosts'.

The word "bot" in this sense means a maggot. 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 and are sometimes more harmful.

, the mouse botfly, parasitizes small mammals all around North America.

The bot fly will hijack a mosquito to inject the host with the eggs.

Family Oestridae
The Oestridae now are generally defined as including the former families, , , and  as.

The Oestridae, in turn, are a family within the superfamily, together with the families , , , and.

Of families of flies causing, the Oestridae include the highest proportion of species whose larvae live as obligate s within the bodies of s. Roughly 150 species are known worldwide. Most other species of flies implicated in myiasis are members of related families, such as blow-flies.

Infestation
Botflies deposit eggs on a host, or sometimes use an intermediate vector such as the common, mosquitoes, and, in the case of D. hominis, a species of tick. After mating, the female human 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'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 lifespan 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. Intermediate vectors are often used, since a number of animal hosts recognize the approach of a botfly and flee.

Eggs are deposited on animal 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 after ingestion by licking.

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 l stage in soil. They do not kill the host animal, thus they are true.

The equine botflies present seasonal difficulties to caretakers, as they lay eggs on the insides of horses' front legs, on the  and  and sometimes on the  or, 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, 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. Removal of the eggs (which adhere to the host's hair) is difficult, since the bone and 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. Botflies can be controlled with several types of dewormers, including, , and.

In cattle, the lesions caused by these flies can become infected by , a that causes, characterized by rapid-growing, hard lumps beneath the skin of the animal. Without antibiotics, an affected animal will die within 3-11 months.

, the human botfly, occasionally uses humans to host its larvae. The larva, because of its spines, can pose an extremely painful subepidermal condition. The fastest way to remove a botfly is by putting a generous amount of iodine in the hole. The botfly will react instantly by poking out of the hole. Another removal method is to use the tree sap of the mata, found in Costa Rica, which is reputed to kill the larva, yet leave its body in the skin. Additionally, one can attempt to seal the breathing hole of the larva with or ; after a day, with a clinical professional, the breathing hole is enlarged and the larva is removed with forceps. Squeezing the larvae out is not recommended, as it can cause the larvae to rupture; its bodily fluids have been known to cause severe. Use of can work, but carries additional risk of infection because portions of the larva's  can be broken off by the tape and make the remainder of the body difficult to remove.

As human food
In cold climates supporting or -reliant populations, large quantities of  (caribou warble fly) maggots are available to human populations during the butchery of animals.

The sixth episode of season one of the television series Beyond Survival, titled "The – Survivors of the Future", features survival expert  and two Inuit guides hunting caribou on the northern coast of  near, , 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 people.

Copious art dating back to the in Europe confirms their consumption in premodern times, as well.