''Gasterophilus haemorrhoidalis'' (also called nose botfly or lip botfly) is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

'' Gasterophilus'' that lays eggs on the lips and around the mouth of

horse The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 mi ...

mule The mule is a domestic equine hybrid between a donkey, and a horse. It is the offspring of a male donkey (a jack) and a female horse (a mare). The horse and the donkey are different species, with different numbers of chromosomes; of the two ...

s and

donkey The donkey or ass is a domesticated equine. It derives from the African wild ass, ''Equus africanus'', and may be classified either as a subspecies thereof, ''Equus africanus asinus'', or as a separate species, ''Equus asinus''. It was domes ...

s. Their hatching is simulated by moisture from licking or feeding of hosts. First instar development: Penetrate epidermis of the lips of hosts and migrate into mouth. Second instar: move to stomach and duodenum(first section of small intestine) Third instar: larvae become detached after some time and then pass to the rectum and re-attach themselves. Appearance: Postsutural scutum with ground color uniformly brown or black legs yellowish brown, with femora distinctly darkened; abdomen ground color dark brown or black, with reddish-yellow or orangish setae posteriorl. Males possess a surstylus that abruptly tapers distally, with short surstylar setae that reach at most halfway to the sagittal plane. Regarding egg description, the pedicel is long and slender, with a width/length ratio of approximately 1/6 in lateral view, comprising 2/5 of the total egg length. Egg Description: Pedicel long and slender, with width/length ratio around 1/6 in lateral view, accounting for 2/5 of the total egg length. In

Equidae Equidae (commonly known as the horse family) is the Taxonomy (biology), taxonomic Family (biology), family of Wild horse, horses and related animals, including Asinus, asses, zebra, zebras, and many extinct species known only from fossils. The fa ...

, third-stage larvae attach to the stomach, but also to the rectum, sometimes in great numbers.Johannes Kaufmann, Parasitic Infections of Domestic Animals, Birkhäuser Verlag, Basel, Boston, Berlin, 1996, . Heavy infestation can cause anal

prolapse In medicine, prolapse is a condition in which organ (anatomy), organs fall down or slip out of place. It is used for organs protruding through the vagina, rectum, or for the misalignment of the valves of the heart. A spinal disc herniation is al ...

in foals and mules. They do not parasitise humans.

References

External links

GNWT - Environment and Natural Resources 'Nose Bot' page
Oestridae Parasitic flies Insects described in 1758 Taxa named by Carl Linnaeus {{parasitic insect-stub