Difference between revisions of "Calliphoridae"
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(Created page with 'thumb|right|150px|Pollenia rudis (Calliphoridae) - Richard Bartz, Munich - Wikimedia Commons [[Image:Lucilia cuprina.jpg|thumb|right|150px|''Lucilia c…') |
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− | [[Image:Calliphoridae.jpg|thumb|right|150px| | + | [[Image:Calliphoridae.jpg|thumb|right|150px|Pollenia rudis (Calliphoridae) - Richard Bartz, Munich - Wikimedia Commons]] |
− | [[Image:Lucilia cuprina.jpg|thumb|right|150px|''Lucilia cuprina'' | + | [[Image:Lucilia cuprina.jpg|thumb|right|150px|''Lucilia cuprina'' - Wikimedia Commons]] |
− | [[Image:Blow fly head.jpg|thumb|right|150px| | + | [[Image:Blow fly head.jpg|thumb|right|150px|Blowfly Head Close Up - Martin Pot - Wikimedia Commons]] |
*The ''Calliphoridae'' family are '''facultative''' parasites | *The ''Calliphoridae'' family are '''facultative''' parasites | ||
− | *Cause | + | *Cause '''blowfly strike''' |
*If the fly lays eggs on an animal, the animal is said to be '''blown''' | *If the fly lays eggs on an animal, the animal is said to be '''blown''' | ||
Line 29: | Line 29: | ||
*''Lucilia cuprina''; South Africa and Australia | *''Lucilia cuprina''; South Africa and Australia | ||
− | * | + | *''Chrysomya spp.''; Africa, Asia and Australia |
− | * | + | *''Wohlfahrtia''; Fleshfly |
Line 76: | Line 76: | ||
*Flies can survive the winter as pupae and emerge the next spring | *Flies can survive the winter as pupae and emerge the next spring | ||
− | |||
− | + | '''Epidemiology''' | |
+ | <br>Blowflies are divided into categories depending on their ability to initiate strike | ||
+ | *Primary flies are capable of initiating a strike on living sheep. Larvae can penetrate intact skin | ||
+ | **''Lucilia'' | ||
+ | **''Phormia'' | ||
+ | **''Calliphora spp.'' | ||
+ | *Secondary flies cannot initiate a strike. Larvae attack an area already struck or damaged, extending it | ||
+ | **''Calliphora spp.'' | ||
+ | **''Chrysomya spp.'' (in warmer climates) | ||
− | [[Category: | + | *Tertiary flies attack lesions on carcasses which have become dry |
− | [[Category: | + | **''Musca'' |
+ | **''Sarcophaga spp.'' | ||
+ | |||
+ | |||
+ | Predisposing factors to flystrike | ||
+ | *Temperature | ||
+ | **Temperature in the spring will determine when the overwintering larvae hatch | ||
+ | **High temperature and humidity will create a microclimate in the fleece, attracting adult flies to lay eggs | ||
+ | |||
+ | *Rainfall | ||
+ | **Persistent rainfall will make the fleece microclimate attractive to adult flies. Females lay eggs after the rain ceases | ||
+ | **Breeds with long, fine wool are the most susceptible | ||
+ | |||
+ | *Host susceptibility | ||
+ | **This is increased when putrefactive odours develop on the fleece due to bacterial decomposition of organic matter following soiling with urine or faeces | ||
+ | **Merino sheep have a narrow breech area with excessive wrinkling making them more susceptible to soiling | ||
+ | **A narrow opening of the penile sheath in rams and wethers may result in accumulation of urine and increase blowfly strike in this area | ||
+ | **Cuts during shearing, fighting and barbed wire will also increase the incidence of blowfly strike | ||
+ | |||
+ | |||
+ | Blowfly season | ||
+ | *Temperate regions in '''June to September''' | ||
+ | **Mostly in unshorn sheep in June | ||
+ | **Lambs from July to September | ||
+ | |||
+ | *Warmer regions have a more prolonged season due to greater number of blowfly generations | ||
+ | |||
+ | |||
+ | '''Pathogenesis''' | ||
+ | *Severe skin damage | ||
+ | **Larvae lacerate skin with oral hooks and liquefy host tissue by secreting proteolytic enzymes | ||
+ | |||
+ | *Skin lesions are extended and deepened | ||
+ | **Secondary blowfly attack | ||
+ | **Flies attracted to odour of decomposing tissue | ||
+ | |||
+ | *Secondary bacterial infection | ||
+ | |||
+ | *Production losses | ||
+ | **Irritation and distress associated with skin lesions | ||
+ | **Poor weight gain (often the first clinical sign) | ||
+ | |||
+ | *Risk of strike is highest in warm, moist weather | ||
+ | |||
+ | |||
+ | '''Clinical signs''' | ||
+ | *Anorexia | ||
+ | *Listlessness | ||
+ | *Animals standing apart from flock | ||
+ | |||
+ | *Fleece may appear darker, be damp and have a foul smell | ||
+ | |||
+ | |||
+ | '''Control''' | ||
+ | *Prophylactic [[Ectoparasiticides|insecticide]] treatment | ||
+ | **Must kill larvae and remain in fleece to prevent flies from laying eggs | ||
+ | **Applied by spraying, dipping, spray race or jetting | ||
+ | |||
+ | *Insect growth regulators | ||
+ | **Pour-on | ||
+ | **2-4 month protection depending upon the product used | ||
+ | |||
+ | *Effective worm control | ||
+ | **To minimise diarrhoea and therefore soiled fleece | ||
+ | |||
+ | *Crutching to prevent soiling | ||
+ | |||
+ | *'Mule's operation' | ||
+ | **Surgical removal of breech skin in Merino breeds | ||
+ | |||
+ | *Tail docking of lambs | ||
+ | |||
+ | *Proper carcass disposal | ||
+ | **Eliminates fly breeding sites | ||
+ | |||
+ | *Vaccination | ||
+ | **Experimental use against ''Luculia cuprina'' in Australia[[Category:Parasites]][[Category:Flies]][[Category:Myiasis_Producing_Flies]] |
Revision as of 19:53, 30 March 2010
- The Calliphoridae family are facultative parasites
- Cause blowfly strike
- If the fly lays eggs on an animal, the animal is said to be blown
- The damage the larvae cause to the animal is known as strike
- Worldwide distribution
- Affects sheep mostly
- Rabbits can also be affected
Species of veterinary importance in Europe
- Lucilia sericata; Greenbottle
- Phormia terra-novae; Blackbottle
- Calliphora erythrocephala; Bluebottle
- Calliphora vomitoria; Bluebottle
Species of veterinary importance in the Tropics
- Lucilia cuprina; South Africa and Australia
- Chrysomya spp.; Africa, Asia and Australia
- Wohlfahrtia; Fleshfly
Recognition of Adults
- Medium sized flies under 10mm long
- Metallic sheen to abdomen
- Colour depends on species
- Clear wings
Recognition of Larvae
- Smooth maggots
- 10-15mm long
- Spiracles and stigmatic plates on the tail can be used for species differentiation
Life cycle
- Eggs laid in wounds, soiled fleece and on carrion
- Females attracted by the odour emitted
- Clusters of yellow-cream eggs laid
- Larvae hatch 24 hours later and crawl down onto the skin
- Feed rapidly
- Grow rapidly
- Moult twice before becoming full maggots
- Process takes 1-2 weeks
- Larvae fall to the ground to pupate
- Adult emerges in under 1 week (during summer)
- The female reaches sexual maturity after a protein meal
- Lays eggs in batches of 100-200
- Adult flies survive for 1 month
- Four generations can develop between May and September
- In warmer climates, up to 9 or 10 generations can develop per year
- Flies can survive the winter as pupae and emerge the next spring
Epidemiology
Blowflies are divided into categories depending on their ability to initiate strike
- Primary flies are capable of initiating a strike on living sheep. Larvae can penetrate intact skin
- Lucilia
- Phormia
- Calliphora spp.
- Secondary flies cannot initiate a strike. Larvae attack an area already struck or damaged, extending it
- Calliphora spp.
- Chrysomya spp. (in warmer climates)
- Tertiary flies attack lesions on carcasses which have become dry
- Musca
- Sarcophaga spp.
Predisposing factors to flystrike
- Temperature
- Temperature in the spring will determine when the overwintering larvae hatch
- High temperature and humidity will create a microclimate in the fleece, attracting adult flies to lay eggs
- Rainfall
- Persistent rainfall will make the fleece microclimate attractive to adult flies. Females lay eggs after the rain ceases
- Breeds with long, fine wool are the most susceptible
- Host susceptibility
- This is increased when putrefactive odours develop on the fleece due to bacterial decomposition of organic matter following soiling with urine or faeces
- Merino sheep have a narrow breech area with excessive wrinkling making them more susceptible to soiling
- A narrow opening of the penile sheath in rams and wethers may result in accumulation of urine and increase blowfly strike in this area
- Cuts during shearing, fighting and barbed wire will also increase the incidence of blowfly strike
Blowfly season
- Temperate regions in June to September
- Mostly in unshorn sheep in June
- Lambs from July to September
- Warmer regions have a more prolonged season due to greater number of blowfly generations
Pathogenesis
- Severe skin damage
- Larvae lacerate skin with oral hooks and liquefy host tissue by secreting proteolytic enzymes
- Skin lesions are extended and deepened
- Secondary blowfly attack
- Flies attracted to odour of decomposing tissue
- Secondary bacterial infection
- Production losses
- Irritation and distress associated with skin lesions
- Poor weight gain (often the first clinical sign)
- Risk of strike is highest in warm, moist weather
Clinical signs
- Anorexia
- Listlessness
- Animals standing apart from flock
- Fleece may appear darker, be damp and have a foul smell
Control
- Prophylactic insecticide treatment
- Must kill larvae and remain in fleece to prevent flies from laying eggs
- Applied by spraying, dipping, spray race or jetting
- Insect growth regulators
- Pour-on
- 2-4 month protection depending upon the product used
- Effective worm control
- To minimise diarrhoea and therefore soiled fleece
- Crutching to prevent soiling
- 'Mule's operation'
- Surgical removal of breech skin in Merino breeds
- Tail docking of lambs
- Proper carcass disposal
- Eliminates fly breeding sites
- Vaccination
- Experimental use against Luculia cuprina in Australia