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| | '''[[Dermatobia hominis|''Dermatobia hominis'']] | | '''[[Dermatobia hominis|''Dermatobia hominis'']] |
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| | + | '''[[Calliphoridae|''Calliphoridae'']] |
| | </big> | | </big> |
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| − | ==Calliphoridae==
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| − | [[Image:Calliphoridae.jpg|thumb|right|150px|Pollenia rudis (Calliphoridae) - Richard Bartz, Munich - Wikimedia Commons]]
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| − | [[Image:Lucilia cuprina.jpg|thumb|right|150px|''Lucilia cuprina'' - Wikimedia Commons]]
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| − | [[Image:Blow fly head.jpg|thumb|right|150px|Blowfly Head Close Up - Martin Pot - Wikimedia Commons]]
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| − | *The ''Calliphoridae'' family are '''facultative''' parasites
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| − |
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| − | *Cause '''blowfly strike'''
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| − |
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| − | *If the fly lays eggs on an animal, the animal is said to be '''blown'''
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| − |
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| − | *The damage the larvae cause to the animal is known as '''strike'''
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| − |
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| − | *Worldwide distribution
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| − |
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| − | *Affects sheep mostly
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| − | **Rabbits can also be affected
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| − | '''Species of veterinary importance in Europe'''
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| − | *''Lucilia sericata''; Greenbottle
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| − |
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| − | *''Phormia terra-novae''; Blackbottle
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| − | *''Calliphora erythrocephala''; Bluebottle
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| − | *''Calliphora vomitoria''; Bluebottle
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| − | '''Species of veterinary importance in the Tropics'''
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| − | *''Lucilia cuprina''; South Africa and Australia
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| − | *''Chrysomya spp.''; Africa, Asia and Australia
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| − |
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| − | *''Wohlfahrtia''; Fleshfly
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| − |
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| − | '''Recognition of Adults'''
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| − | *Medium sized flies under 10mm long
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| − |
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| − | *Metallic sheen to abdomen
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| − | **Colour depends on species
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| − | *Clear wings
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| − |
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| − |
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| − | '''Recognition of Larvae'''
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| − | *Smooth maggots
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| − |
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| − | *10-15mm long
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| − |
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| − | *Spiracles and stigmatic plates on the tail can be used for species differentiation
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| − |
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| − |
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| − | '''Life cycle'''
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| − | *Eggs laid in wounds, soiled fleece and on carrion
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| − | **Females attracted by the odour emitted
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| − | **Clusters of yellow-cream eggs laid
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| − |
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| − | *Larvae hatch 24 hours later and crawl down onto the skin
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| − | **Feed rapidly
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| − | **Grow rapidly
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| − | **Moult twice before becoming full maggots
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| − | **Process takes 1-2 weeks
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| − |
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| − | *Larvae fall to the ground to pupate
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| − |
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| − | *Adult emerges in under 1 week (during summer)
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| − |
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| − | *The female reaches sexual maturity after a protein meal
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| − | **Lays eggs in batches of 100-200
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| − |
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| − | *Adult flies survive for 1 month
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| − |
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| − | *'''Four generations can develop between May and September '''
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| − | **In warmer climates, up to 9 or 10 generations can develop per year
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| − |
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| − | *Flies can survive the winter as pupae and emerge the next spring
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| − |
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| − |
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| − | '''Epidemiology'''
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| − | <br>Blowflies are divided into categories depending on their ability to initiate strike
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| − | *Primary flies are capable of initiating a strike on living sheep. Larvae can penetrate intact skin
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| − | **''Lucilia''
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| − | **''Phormia''
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| − | **''Calliphora spp.''
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| − |
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| − | *Secondary flies cannot initiate a strike. Larvae attack an area already struck or damaged, extending it
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| − | **''Calliphora spp.''
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| − | **''Chrysomya spp.'' (in warmer climates)
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| − |
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| − | *Tertiary flies attack lesions on carcasses which have become dry
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| − | **''Musca''
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| − | **''Sarcophaga spp.''
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| − | Predisposing factors to flystrike
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| − | *Temperature
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| − | **Temperature in the spring will determine when the overwintering larvae hatch
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| − | **High temperature and humidity will create a microclimate in the fleece, attracting adult flies to lay eggs
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| − |
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| − | *Rainfall
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| − | **Persistent rainfall will make the fleece microclimate attractive to adult flies. Females lay eggs after the rain ceases
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| − | **Breeds with long, fine wool are the most susceptible
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| − |
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| − | *Host susceptibility
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| − | **This is increased when putrefactive odours develop on the fleece due to bacterial decomposition of organic matter following soiling with urine or faeces
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| − | **Merino sheep have a narrow breech area with excessive wrinkling making them more susceptible to soiling
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| − | **A narrow opening of the penile sheath in rams and wethers may result in accumulation of urine and increase blowfly strike in this area
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| − | **Cuts during shearing, fighting and barbed wire will also increase the incidence of blowfly strike
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| − |
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| − | Blowfly season
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| − | *Temperate regions in '''June to September'''
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| − | **Mostly in unshorn sheep in June
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| − | **Lambs from July to September
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| − |
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| − | *Warmer regions have a more prolonged season due to greater number of blowfly generations
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| − |
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| − |
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| − | '''Pathogenesis'''
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| − | *Severe skin damage
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| − | **Larvae lacerate skin with oral hooks and liquefy host tissue by secreting proteolytic enzymes
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| − |
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| − | *Skin lesions are extended and deepened
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| − | **Secondary blowfly attack
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| − | **Flies attracted to odour of decomposing tissue
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| − | *Secondary bacterial infection
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| − |
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| − | *Production losses
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| − | **Irritation and distress associated with skin lesions
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| − | **Poor weight gain (often the first clinical sign)
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| − |
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| − | *Risk of strike is highest in warm, moist weather
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| − |
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| − |
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| − | '''Clinical signs'''
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| − | *Anorexia
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| − | *Listlessness
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| − | *Animals standing apart from flock
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| − |
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| − | *Fleece may appear darker, be damp and have a foul smell
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| − | '''Control'''
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| − | *Prophylactic [[Ectoparasiticides|insecticide]] treatment
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| − | **Must kill larvae and remain in fleece to prevent flies from laying eggs
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| − | **Applied by spraying, dipping, spray race or jetting
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| − |
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| − | *Insect growth regulators
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| − | **Pour-on
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| − | **2-4 month protection depending upon the product used
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| − |
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| − | *Effective worm control
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| − | **To minimise diarrhoea and therefore soiled fleece
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| − |
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| − | *Crutching to prevent soiling
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| − |
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| − | *'Mule's operation'
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| − | **Surgical removal of breech skin in Merino breeds
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| − |
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| − | *Tail docking of lambs
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| − |
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| − | *Proper carcass disposal
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| − | **Eliminates fly breeding sites
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| − | *Vaccination
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| − | **Experimental use against ''Luculia cuprina'' in Australia
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| | *[http://www.strikewise.com/index.html| Blowfly strike] | | *[http://www.strikewise.com/index.html| Blowfly strike] |
| | + | [[Category:Parasites]][[Category:Flies]][[Category:Myiasis_Producing_Flies]] |
| | [[Category:Parasites]][[Category:Flies]][[Category:Myiasis_Producing_Flies]] | | [[Category:Parasites]][[Category:Flies]][[Category:Myiasis_Producing_Flies]] |