Difference between revisions of "Gasterophilus spp."
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| − | + | [[Image:Horse Bot Fly.jpg|thumb|right|150px|Horse Bot Fly - Dennis Ray - Wikimedia Commons]] | |
| − | + | *Also known as the horse bot fly | |
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| − | [[Image:Horse Bot Fly.jpg|thumb|right|150px| | ||
| − | Also known as | ||
| − | + | *Obligate parasites of equids | |
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| − | + | *Spend most of life cycle in the equine stomach | |
| + | **Of little pathogenic significance | ||
| − | + | *Three important species (in the UK) | |
| − | ''G. intestinalis'' which is the most common | + | **''G. intestinalis'' which is the most common |
| + | **''G. nasalis'' | ||
| + | **''G. haemorrhoidalis'' which is rare | ||
| − | ''G. nigricornis'' | + | *Two other important veterinary species |
| + | **''G. nigricornis'' | ||
| + | **''G. inermis'' | ||
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| − | + | '''Recognition''' | |
| − | + | *Medium to large flies at 10-20mm long | |
| − | + | *Look similar to drone bumble bees | |
| + | **Body covered with dense yellow hair | ||
| + | **Dark coloured hairs produce a banding pattern | ||
| − | + | *Clear wings with brown patches | |
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| − | + | '''Life cycle''' | |
| + | *Adults are most active in '''late summer''' | ||
| − | Eggs are laid on the body | + | *Eggs are laid on the body and 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 |
| − | ''G. intestinalis'' eggs are laid in the hair of the shoulders and | + | **''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 | ||
| − | + | *Creamy-white eggs | |
| − | + | *1-2mm in length | |
| − | + | *Larvae crawl into the mouth and penetrate the tissues of the tongue and buccal mucosa | |
| − | + | *Larvae then emerge after a couple of weeks and are swallowed | |
| − | + | *Larvae pass into the [[Forestomach - Anatomy & Physiology|stomach]] and attach to the gastric mucosa | |
| + | **Larvae are now known as '''bots''' | ||
| − | + | *Each species attaches to a specific part of the stomach | |
| + | **''G. intestinalis'' attaches to the cardiac region | ||
| + | **''G. nasalis'' attaches to the pylorus | ||
| − | + | *After 10-12 months in the stomach, the larvae detach and are passed out in the faeces | |
| − | + | **''G. haemorrhoidalis'' attaches to the rectal mucosa before being passed out | |
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| + | *Larvae pupate on the ground | ||
| − | + | *Adults hatch after 1-2 months and survive from a few days to 2 weeks | |
| + | **Adults have non-functional mouthparts so cannot feed | ||
| − | + | *There is only '''1 generation per year''' in temperate regions of the world | |
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| + | '''Pathogenesis''' | ||
| + | *Adults cause annoyance when egg laying | ||
| + | **Disturbance and panic can ensue | ||
| − | [[ | + | *Larvae cause a marked inflammatory reaction when attached to the gastric mucosa |
| − | [[Category: | + | **Ring like thickening around the base of each attached larvae |
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| + | *Large numbers of larvae may interfere with the passage of food and action of gastric sphincters | ||
| + | |||
| + | *''G. haemorrhoidalis'' can cause mild irritation to the rectal wall | ||
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| + | *Host reaction to larvae in the mouth is minimal | ||
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| + | '''Control''' | ||
| + | *Treatment of horses with [[Ectoparasiticides|insecticides]] over winter | ||
| + | **Breaks the life cycle as all the population are present as bots in the [[Forestomach - Anatomy & Physiology|stomach]] | ||
| + | |||
| + | *If eggs are present in late summer, the horse's coat can be sponged with an [[Ectoparasiticides|insecticide]] | ||
| + | **Stimulates hatching | ||
| + | **Kills larvae | ||
| + | |||
| + | [[Category:Myiasis_Producing_Flies]] | ||
Revision as of 12:29, 5 April 2010
- Also known as the horse bot fly
- Obligate parasites of equids
- Spend most of life cycle in the equine stomach
- Of little pathogenic significance
- Three important species (in the UK)
- G. intestinalis which is the most common
- G. nasalis
- G. haemorrhoidalis which is rare
- Two other important veterinary species
- G. nigricornis
- G. inermis
Recognition
- Medium to large flies at 10-20mm long
- Look similar to drone bumble bees
- Body covered with dense yellow hair
- Dark coloured hairs produce a banding pattern
- Clear wings with brown patches
Life cycle
- Adults are most active in late summer
- Eggs are laid on the body and 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
- 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
- Creamy-white eggs
- 1-2mm in length
- Larvae crawl into the mouth and penetrate the tissues of the tongue and buccal mucosa
- Larvae then emerge after a couple of weeks and are swallowed
- Larvae pass into the stomach and attach to the gastric mucosa
- Larvae are now known as bots
- Each species attaches to a specific part of the stomach
- G. intestinalis attaches to the cardiac region
- G. nasalis attaches to the pylorus
- After 10-12 months in the stomach, the larvae detach and are passed out in the faeces
- G. haemorrhoidalis attaches to the rectal mucosa before being passed out
- Larvae pupate on the ground
- Adults hatch after 1-2 months and survive from a few days to 2 weeks
- Adults have non-functional mouthparts so cannot feed
- There is only 1 generation per year in temperate regions of the world
Pathogenesis
- Adults cause annoyance when egg laying
- Disturbance and panic can ensue
- Larvae cause a marked inflammatory reaction when attached to the gastric mucosa
- Ring like thickening around the base of each attached larvae
- Large numbers of larvae may interfere with the passage of food and action of gastric sphincters
- G. haemorrhoidalis can cause mild irritation to the rectal wall
- Host reaction to larvae in the mouth is minimal
Control
- Treatment of horses with insecticides over winter
- Breaks the life cycle as all the population are present as bots in the stomach
- If eggs are present in late summer, the horse's coat can be sponged with an insecticide
- Stimulates hatching
- Kills larvae