Difference between revisions of "Psoroptes ovis"

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*Adult females are large mites at 750μm in length
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{{Taxobox
 
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|name              = Psoroptes
 
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|kingdom            = Animalia
 
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|phylum            = [[:Category:Arthropods|Arthropoda]]
 
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|class              = [[:Category:Arachnida|Arachnida]]
 
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|sub-class          = Acari
 
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|order              = Sarcoptiformes
 
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|super-family      =
 
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|family            = Psoroptidae
 
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|sub-family        =
 
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|genus              = Psoroptes
 
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|species            =''Psoroptes ovis
 
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}}
 
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Also known as: '''''Scab mite
 
  
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==Introduction==
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*Males identified by copulatory suckers and paired posterior lobes
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''Psoroptes ovis'' are astigmatic, non-burrowing mites of the class ''Arachnida''. They are around 750μm (0.75mm) in length, and oval shaped. They are extremely pruritic, and cause a contagious skin disease, [[Psoroptic Mange]], as well as a loss in body condition. They also cause the host to rub and bite the infected areas, resulting in further trauma.
 
  
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Predilection site: '''Skin'''; particularly on legs, feet, and the base of the tail.
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*Males attach to deutonymphs (second moult after larval stage) in a process called '''copula'''
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**Males remain in copula until females moult for the last time
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**Copulation occurs
  
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This mite is found worldwide, but has been '''eradicated from Australia and New Zealand'''.
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*Life cycle last '''14 days'''
  
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==Hosts==
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*Transmitted by direct contact between sheep
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Sheep, cattle, goats, horses, rabbits, and camelids.
 
  
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==Identification==
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*Indirect transmission can also occur
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The adult ''Psoroptes'' are around 0.75mm in length and oval in shape. 
 
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They have three-jointed pedicles, each with suckers on the ends; also known as '''pulvilli'''.
 
  
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The legs of adult females are all approximately the same length.  However, in the males the fourth pair of legs is significantly shorter than the rest. The males also tend to be smaller then the females.
 
  
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The males may also be identified via copulatory suckers and paired posterior lobes.
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'''Pathogenesis'''
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The males attach to female tritonymphs, sometimes protonymphs, in a process called '''copula'''. The males then remain in copula until the females moult for the final time. Copulation then occurs.
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*Economically important ectoparasite of sheep
  
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==Life Cycle==
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*Causes '''sheep scab'''
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The life cycle is confined to the skin surface. The eggs are relatively large, and within around 2 days transform into a '''hexapod larva'''.  The larvae then moult into a '''protonymph''', which then subsequently moults into a '''tritonymph'''. Finally the tritonymph moults to become a mature adult.
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**Wool loss, restlessness, biting, scratching of infested area and decreased productivity through decreased weight gain
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**Usually seen in '''late autumn''' and '''early winter''' (although may also occur in late summer)
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**Population numbers decline after shearing due to a change in the micro-climate, then build up again as the fleece grows
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**'''Notifiable in UK'''
  
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Each stage takes around 2 days to complete.  The total duration from egg to adult, takes around 10 days, but this figure can be longer. Adult female life expectancy is around one month and she lays 2-3 eggs per day, hence a mite population on an animal can expand rapidly.
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*Mites found under scabs and in skin folds
  
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Transmission is generally from direct contact with infected animals, such as at markets or in livestock transporters, but as the mite can survive off the host indirect transmission may also occur.
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*Lesions most common on flanks, neck, back and shoulders
  
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{{Learning
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*Causes pruritic condition of cattle
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|literature search = [http://www.cabdirect.org/search.html?q=title%3A%28%22Psoroptes+ovis%22%29 ''Psoroptes ovis'' publications]
 
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|Vetstream = [https://www.vetstream.com/canis/search?s=mite Mites]
 
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}}
 
  
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*Active in keratin layer
  
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{{review}}
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*Mouthparts abrade the skin
  
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*Antigenic material in mite faeces can lead to hypersensitivity reactions
  
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[[Category:Non-Burrowing Mites]]
 
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[[Category:Sheep Parasites]][[Category:Cattle Parasites]][[Category:Horse Parasites]]
 
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[[Category:Goat Parasites]]
 
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[[Category:Camelid Parasites]]
 
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[[Category:Rabbit Parasites]]
 
  
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[[Category:Expert_Review - Parasites]]
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[[Category:Sheep]][[Category:Cattle]]
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[[Category:To_Do_-_Max]]

Revision as of 10:49, 9 July 2010

  • Adult females are large mites at 750μm in length
  • Males identified by copulatory suckers and paired posterior lobes
  • Males attach to deutonymphs (second moult after larval stage) in a process called copula
    • Males remain in copula until females moult for the last time
    • Copulation occurs
  • Life cycle last 14 days
  • Transmitted by direct contact between sheep
  • Indirect transmission can also occur


Pathogenesis

  • Economically important ectoparasite of sheep
  • Causes sheep scab
    • Wool loss, restlessness, biting, scratching of infested area and decreased productivity through decreased weight gain
    • Usually seen in late autumn and early winter (although may also occur in late summer)
    • Population numbers decline after shearing due to a change in the micro-climate, then build up again as the fleece grows
    • Notifiable in UK
  • Mites found under scabs and in skin folds
  • Lesions most common on flanks, neck, back and shoulders
  • Causes pruritic condition of cattle
  • Active in keratin layer
  • Mouthparts abrade the skin
  • Antigenic material in mite faeces can lead to hypersensitivity reactions
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