Changes

[[Image:Horse Bot Fly.jpg|thumb|right|150px|Horse Bot Fly - Dennis Ray - Wikimedia Commons]]

[[Image:Horse Bot Fly.jpg|thumb|right|150px|''Horse Bot Fly'' <br> Dennis Ray 2005, Wikimedia Commons]]

===Introduction===

==Introduction==

The species ''Gasterophilus'', is more commonly referred to as the 'Bot fly.'  It is an obligate parasite found on horses, donkeys, mules, zebras and elephants.   

The species ''Gasterophilus'' is of the family [[Oestridae]], and is more commonly referred to as the 'Bot fly.'  It is an obligate parasite found on horses, donkeys, mules, zebras and elephants.   

Infection is particularly common in horses, with around 30-60% infected during the winter months.

Infection is particularly common in horses, with around 30-60% infected during the winter months.

''G. nigricornis'' and ''G. inermis'' are also of veterinary significance, but not currently within the UK.

''G. nigricornis'' and ''G. inermis'' are also of veterinary significance, but not currently within the UK.

'''Scientific Classification'''

[[Image:Gasterophilus larvae.jpg|150px|thumb|right|''Gasterophilus larvae'' <br> Lamiot 2007, Wikimedia Commons]]

==Identification==

 

 

===Identification===

Gasterophilus are medium to large flies at 10-20mm long, and are thought to look similar to drone bumble bees.

Gasterophilus are medium to large flies at 10-20mm long, and are thought to look similar to drone bumble bees.

Both ''G. haemorrhoidalis'' and ''G. nasalis'' have spikes on the ventral surface of the larval segments arranged in two rows. ''G. intestinalis'' have mouth parts that are not uniformly curved dorsally and the body spikes present have blunt ended tips.

Both ''G. haemorrhoidalis'' and ''G. nasalis'' have spikes on the ventral surface of the larval segments arranged in two rows. ''G. intestinalis'' have mouth parts that are not uniformly curved dorsally and the body spikes present have blunt ended tips.

===Life Cycle===

==Life Cycle==

 

L1 are extremely small and motile, and begin development in the mouth, tongue and gums of the host.  The development of L1 into L2 occurs on the pharynx.  L2 then attaches to the base of the tongue and slowly migrates to the stomach.

L1 are extremely small and motile, and begin development in the mouth, tongue and gums of the host.  The development of L1 into L2 occurs on the pharynx.  L2 then attaches to the base of the tongue and slowly migrates to the stomach.

L3 attaches to the squamous gastric mucosa along the margo pliacatus, in the case of ''G. intestinalis''. ''G. nasalis'' attaches to the dorsoproximal part of the duodenum, and ''G. haemorrhoidalis'' attaches to the gastric epithelium within the stomach.

L3 attaches to the squamous gastric mucosa along the margo plicatus, in the case of ''G. intestinalis''. ''G. nasalis'' attaches to the dorsoproximal part of the duodenum, and ''G. haemorrhoidalis'' attaches to the gastric epithelium within the stomach.

The larvae then remain and develop within the stomach for around 10-12 months.  They mature in the following spring or early summer (generally between May and September), detach from their surface and are passed out in the host faeces. ''G. haemorrhoidalis'' also attaches to the rectal mucosa before being passed out.

The larvae then remain and develop within the stomach for around 10-12 months.  They mature in the following spring or early summer (generally between May and September), detach from their surface and are passed out in the host faeces. ''G. haemorrhoidalis'' also attaches to the rectal mucosa before being passed out.

[[Image:Gasterophilus.jpg|200px|thumb|right|'''Gasterophilus (Copyright Notafly, Wikimedia Commons) ''']]

[[Image:Gasterophilus.jpg|200px|thumb|right|''Gasterophilus'' <br> Notafly 2008, Wikimedia Commons]]

The larvae then penetrate the soil, where they transform into pupae and the flies hatch 30 to 40 days later.

The larvae then penetrate the soil, where they transform into pupae and the flies hatch 30 to 40 days later.

Eggs are laid on the body of the host and either hatch spontaneously or are stimulated to hatch through an increase in warmth and moisture from the animal self-grooming. They are laid in different areas according to species;

They are only found on pasture, as they do not survive well on stable bedding.  The pupae are known to be sensitive to frost, moisture and flooding, so the environmental conditions present play a significant role in the success of the parasite.

''G. intestinalis'' eggs are laid in the hair of the shoulders and fore legs. ''G. nasalis'' eggs are laid in the intermandibular area. ''G. haemorrhoidalis'' eggs are laid around the lips

[[Image:Gasterophilus.jpg|200px|thumb|right|'''Gasterophilus (Copyright Notafly, Wikimedia Commons) ''']]

|flashcards = [[Myiasis_Producing_Flies_Flashcards|Myiasis Producing Flies Flashcards]]

|literature search =[http://www.cabdirect.org/search.html?q=title%3A%28%22Gasterophilus%22%29+ ''Gasterophilus'' spp. publications]

|Vetstream = [https://www.vetstream.com/canis/Content/Disease/dis60301.asp Myiasis]

[[Category:Oestridae]]

[[Category:Expert_Review]]

[[Category:To_Do_-_Max]]

[[Category:Horse Parasites]]