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14 Cards in this Set
- Front
- Back
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What are Calliphoridae?
Why important? Characteristics? Major diseases? |
Class Insecta
Order Diptera This is a family commonly known as Blow flies, flesh flies and screw-worm flies LOOOOVE decaying flesh. important environmentally breed in decaying organic matter adults feed on decaying organic material or nectar facultative parasites (usually) Major diseases : blow fly strike of sheep (cutaneous myiasis) screw worm fly (exotic) |
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Role of blowfly strike, succession of species:
What are the most important flies in initiating a blowfly strike? Identify succession based on color: |
1º Green species
1º Lucilia cuprina introduced- 90% of strikes 1º Lucilia sericata introduced-urban areas 2º BROWN Species 3º Black, Blue and Flesh flies. |
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Describe Lucila cuprina..
What is it responsible for? Where and when are eggs laid? Describe instar requirements? Entire lifecycle duration? |
Class INSECTA
order Diptera family Calliphoridae responsible for > 90% of strikes almost obligate parasite can breed in carcases but outcompeted eggs laid in batches in fleece laid in afternoon, hatch at night first instar needs protein meal cannot penetrate skin second instar penetrates skin, feeds on tissues third instar matures by 2-19 days drops to ground at night burrows into soil pupates (3-7 days) overwinters as pupa entire life cycle 17 days (in summer) emerging females need protein meal to produce eggs only mate once Secondary flies can invade and extend the wound Most strikes are 'covert' and heal |
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Describe the clinical signs of Lucila cuprina...
Mortality? |
Class INSECTA
order Diptera family Calliphoridae days 1-2 sheep irritated day 3 temperature rise day 4 maggots drop, smell (!) day 6 temperature falls healing slow but complete in bad year, mortalities can be up to 30% |
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What is the pathogenesis of blowfly strike?
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normal sheep are not struck by flies
need olfactory stimulus to attract flies need proteinaceous exudate on skin for first larval instars |
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What are the types of blowfly strike?
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breech strike
body strike poll strike (rams) pizzle strike (rams & wethers) |
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What is breech strike? What leads to a higher incidence of it?
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commonest form of strike
soiling of fleece by urine or faeces scouring due to nematodes (can reduce prevalence 10 fold) wrinkles predispose to strike |
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What is body strike? How/why does this occur?
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preceded by “fleece rot” or dermatitis
prolonged wetting of skin --- keratin lifts --- protein exudes Pseudomonas spp. proliferate and provide olfactory stimulus also stain wool body conformation (“sway back”) and wrinkles predispose to strike fleece characters (wax content) important |
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Describe the seasonal prevalence of blowfly strike...
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fly numbers determined by temperature and rainfall
flies overwinter as pupae, emerge in spring usually 3 generations in spring summer too dry for eggs and first instars autumn moister & cooler - 2 generations pattern of infection generally bimodal if summer is wet, flies active all summer |
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How is blowfly strike controlled by rendering the sheep less susceptible?
What is the most effective? |
crutching
correct tail docking removal of conformational faults breed for sheep with suitable fleece characteristics **single most successful method : the Mules operation |
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How is blowfly strike controlled by reducing fly numbers?
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treat all strikes seen early in season (?covert strikes)
burn or deeply bury carrion fly traps - drums with meat laced with insecticide genetic manipulation - sterile male methods vaccines - currently under investigation chemicals - organophosphates (resistance widespread) growth regulators (cyromazine; Vetrazin) |
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What is Chrysomya rufifacies?
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Class INSECTA
order Diptera family Calliphoridae common name : the hairy maggot blowfly larva feeds on other maggots |
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What is Chrysomya bezziana?
How is the pupae identified, and where are they found? Dangers of adult stage? |
Class INSECTA
order Diptera family Calliphoridae The old world screw fly not present in Australia identified by bands of spines on each segment Pupae found in the soil Freakin' nasty buggers!!! This is the one where a wound can be rapidly expanded in hours... |
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What is Callitroga hominivorax?
How was it eradicated in the states? |
Class INSECTA
order Diptera family Calliphoridae New World screw worm fly similar to C. bezziana eradicated in USA using sterile male technique recent outbreak in Libya at Melbourne airport in 1991 |
