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96 Cards in this Set
- Front
- Back
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Kingdom:
Phylum: Class: Order: |
Animalia
Arthropoda Arachnida Acarina |
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Four sub-orders of Acarina
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1. Ixodoidea
2. Mesostigamta 3. Prostigmata 4. Astimagata |
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Which sub-order of Acarina refers to ticks?
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Ixodoidea
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Body divisions
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Divided into two parts:
Head: Gnathosoma (i.e. capitulum) Body: Idiosoma |
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Number of legs
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4 pairs in adult
3 pairs in larvae |
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Wings & Antennae
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Absent
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What kind of parasites are ticks?
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Obligate parasites
Females and males both need blood meals, but females are heavier feeders |
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Where is most of the life cycle of ticks spent?
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Off host in environment
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Host specificity
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Variable
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Tick mouthparts
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A = Chelicerae
B = Hypostome C = Palps D = Capituli |
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Function of palps
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Feelers
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Function of chelicerae
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Cut the wound
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Function of hypostome
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Jams into the wound and sucks blood
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What helps to anchor the tick to its host
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Backward facing spines on the hypostome
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If eyes are present where are they found?
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Between the 1st and 2nd pairs of legs
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Life cycle of ticks
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Egg
Larva (6 legs) Nymph (8 legs) Adult (8 legs) No pupal stage |
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How can ticks be classified according to its life cycle?
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One-host tick
Two-host tick Three-host tick |
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One-host tick
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Remains on host from larva to adult
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Two-host tick |
Larvae and nymph feed on one host. Nymph drops off and moults into an adult. Adult finds new host to feed on. |
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Three-host tick
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Drops off for each moult and finds new host each time
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What is feeding timed with
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Moults
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Pathogenic effects of ticks |
Blood loss Irritation, hypersensitivity Damaged hide Reduced growth rate Produce toxins (paralysis) Transmit protozoans |
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Two families of ticks
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Argasidae and Ixodidae
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Which family of ticks is this?
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Argasidae
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Argasidae family
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Soft ticks
No scutum Mouthparts underneathRapid feeders (hours) |
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Which family of ticks is this?
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Ixodidae
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Ixodidae family
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Hard ticks
Scutum present Mouth parts anteriorSlow feeders (days) |
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What is a scutum?
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Plate that the head is attached to
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Three types of ticks in the family Argasidae
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1. Fowl tick
2. "Tampan" ticks 3. Spinose ear tick |
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Fowl tick
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Argas persicus
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Argas persicus
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Argas persicus
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Features of Argas persicus
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Reddish tick
Mouthparts concealed Distinct patterned margin to body |
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Argas persicus life cycle
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Egg
Larvae 2 Nymphal stages Adult |
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Where are eggs of Argas persicus laid?
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In crevices
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How long do eggs of Argas persicus take to hatch?
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3 Weeks
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How long do Argas persicus larva feed for?
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5-10 days
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Where does Argas persicus moult?
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In crevices
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How long does each nymphal stage of Argas persicus last?
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2 weeks
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When do adults and nymphs feed?
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At night (nocturnal)
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How long can Argas persicus larvae survive without food?
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3 months
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How long can Argas persicus adults survive without food?
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3-5 years
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Pathogenesis of Argas persicus
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Anaemia
Irritation Reduced egg production Paralysis caused by larvae (respiratory collapse) Transit Borrelia anserina (tick fever) and protozoan Aegyptianella pullorum |
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Diagnosis of Argas persicus
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Find larvae on birds or find adults/nymphs in sheds
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Treatment of Argas persicus
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Organophosphate spray or kerosene emulsion
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Tampan ticks
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Ornithodoros moubata, Ornithodoros gurneyi
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Features of Ornithodoros ticks
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Similar to Argas ticks but edge of body is rounded, no sutural line
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Where are the two Ornithodoros ticks found?
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O. moubata - Africa O. gurneyi - Australia |
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Ornithodoros gurneyi
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Kangaroo tick
Widespread in inland Australia Found under trees where kangaroos camp Feed on kangaroos, dog and man Cause painful swellings and bites Can transmit Q fever |
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Spinose ear tick
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Otobius megnini
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Where is the Otobius megnini found?
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North America, Africa, recently found in WA
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Otobius megnini
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Adults free living
Larva and nymph live in ears of hosts Hosts: horses, cattle dogs Treatment: ear tags with arthrocidal compounds |
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Classification of the familly Ixodidae
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Prostriata: anal groove in front of anus
Metastriata: anal groove behind anus |
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Prostriata genera
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Ixodes
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Features of Ixodes
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Inornate
No eyes or festoons 22 species in Australia |
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4 Important species of Ixodes
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I. holocyclus and I. cornuatus cause paralysis
I. rubicundus causes paralysis in Africa I. dammini vector of Lyme disease (Borrelia) |
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Life cycle of Ixodes holocyclus
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3 host tick
Larvae and adults in spring Nymphs mainly in autumn Males rarely found on host |
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How long is the life cycle?
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18 months (6 months b/n each feed)
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Natural host of Ixodes holocyclus
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Bandicoot and other native animals
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Pathogenesis of Ixodes holocyclus
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All stages cause irritation and paralysis
Paralysis usually seen 5-6 days after attachment of a female Ascending motor paralysis Intense vasoconstriction Die from paralysis of resp. muscles Young children may become ill with odd death reported |
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How does I. holocyclus cause disease? |
Neurotoxin inhibiting transmission of ACh Cardiovascular fraction in toxin causing intense vaso-constriction |
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Which animals are most susceptible to I. holocyclus?
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Sheep, dogs and cats
Calves and foals are also affected |
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Treatment of I. holocyclus
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Remove tick
Acaricidal wash Hyperimmune serum to neutralise toxin If tick is removed condition may continue to deteriorate for 1-2days |
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Control of I. holocyclus
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Wash with acaricidal agent weekly
Examine dogs regularly Pay attention to ears, under collar and between toes |
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Distribution of I. holocyclus
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Along the east cost of Australia
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Ixodes Holocyclus A = AdultB = Nymph C = Larva |
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Metastriata is divided into two groups what are they?
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Brevirostrata (short mouth parts)
Longirostrata (long mouth parts) |
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Brevirostrata genera
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Boophilus
Dermacentor Haemaphysalis Rhipicephalus |
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Boophilus microplus features
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Inornate
Very short palps and hypostome Palps have ridges Pale legs Eyes present but small Festoons absent Anus hard to see Engorged female has waist |
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What species is this?
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Boophilus microplus
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What is the common name for Boophilus microplus?
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The cattle tick
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Where is Boophilus microplus found?
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Occurs in central & south America, South-east Asia
Introduced into northern Australi |
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Hosts
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Host specific to cattle but occurs occasionally on horses, sheep, dogs & pigs
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Lifecycle of Boophilus microplus
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1 host tick
Eggs hatch Larva climb up grass attach to passing cattle Larva & nymph remain on host Don't spend much time in environment |
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Length of life cycle of Boophilus microplus
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22 days
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Pathogenesis of Boophilus microplus
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Irritation
Damage to hides Anaemia Anorexia Reduced growth rate and milk production Transmit protozoans: Babesia, Anaplasma, Theileria |
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What are Boophilus microplus numbers controlled by?
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Low temperature and humidity
Prefer wet tropic weather |
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Dispersal of Boophilus microplus
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Larvae can migrate in short pasture
Occasionaly be blown up to 30m |
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Host resistance to Boophilus microplus
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Zebu cattle develop much greater resistance to infection than British breeds
Acquired immunity develops in both breeds Hypersensitivity to saliva develops Mast cells & basophils collect around hypostome Histamine released disrupts feeding, increases reflex grooming Larvae detaches or is removed by grooming |
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Control of Boophilus microplus
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Use Zebu cattle instead of British breeds Regular dippingPour-ons Pasture spelling Vaccine (Tick-gard) Chemicals: - macrocyclic lactones (expensive) - growth regulators (flurazuron) - amitraz - pyrethroids |
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Features of Haemaphysalis longicornis
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Lateral projections on palps
Inornate Short palps and hypostome No eyes Well defined festoons 3-host tick |
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Common name for Haemaphysalis longicornis
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Bush tick
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Where does Haemaphysalis longicornis occur?
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Common in SE Asia, introduced into Australia
Occurs in eastern Australia Common in eastern Victoria |
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Hosts of Haemaphysalis longicornis
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Cattle and other hosts (eg. horses, dogs)
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Pathogenesis of Haemaphysalis longicornis
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Anaemia
Hide damage Vector of Babesia gibsoni of dogs |
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Features of Rhipicephalus sanguineus
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Basis capituli projects (hexagonal capitulum)
Forked first coxa |
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Rhipicephalus sanguineus
Arrow points to forked first coxa Circle shows basis capituli projection |
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Common name of Rhipicephalus sanguineus
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Brown dog tick
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Where is Rhipicephalus sanguineus found?
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Common in tropical countries
Introduced to Australia Common in northern Australia Uncommon but present in Melbourne |
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Pathogenesis of Rhipicephalus sanguineus
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Anaemia and irritation
Vector of Babesia canis of dogs |
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Longirostrata genera
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Amblyomma
Aponomma Hyalomma |
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Aponomma & Amblyomma
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Aponomma & Ambylomma
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Often brightly coloured
Important on cattle in Africa and USA Most Australian species occur on reptiles Also one on wombat, echidna and kangaroo |
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Amblyomma triguttatum
(around cloaca of kangaroo) |
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Aponomma auruginans
(wombat) |
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Aponomma hydrosauri
(on a snake: note abscesses) |
