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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*The ''Calliphoridae'' family are '''facultative''' parasites
 
*The ''Calliphoridae'' family are '''facultative''' parasites
  
*Cause '''blowfly strike'''
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*Cause <big>[[Blowfly Strike|'''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'''
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'''Epidemiology'''
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[[Category:Parasites]][[Category:Flies]][[Category:Myiasis_Producing_Flies]]
<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)
 
 
 
*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 [[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 19:55, 30 March 2010

Pollenia rudis (Calliphoridae) - Richard Bartz, Munich - Wikimedia Commons
Lucilia cuprina - Wikimedia Commons
Blowfly Head Close Up - Martin Pot - Wikimedia Commons
  • The Calliphoridae family are facultative parasites
  • 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