Arachnida - Ixodida Flashcards
How many pairs of legs in adult?
4
What are the 2 body parts called?
gnathosoma = capitulum idiossoma = the rest
Type of parasite
obligate (needs blood meal)
Soft ticks
Argasidae
Hard ticks
Ixodidae
legs in larvae
6
legs in nymph
8
One host tick lifecycle
Two host tick lifecycle
3 host tick lifecycle
Soft tick lifecycle
Up to 7 nymphal stages
Pathogenic effects
Blood loss (up to 5ml)
irritation and hypersensitivity
damage hide
reduce growth rate
produce toxins
transmit protozoans
Features of argasidae
Soft
no scutum
mouthparts underneath
rapid feeders (hours)
Features of ixodidae
hard tick
scutum present
mouthparts anterior
slow feeders (days)
The fowl tick
argas persicus
What is this tick and what are its features?
Argas persicus
red fowl tick
mouthparts concealed
distinct patterned margin to body (no festunes)
Lifecycle of Argus persicus
eggs laid in cracks
hatch in 3 weeks
larvae feed for 5-10 days
moult in crevices
nymphs feed in 2hrs (4 nymphal stages)
nymph and adult are nocturnal
larvae survivev 3 months without food
Adults survive 3-5 years without food
Argus Persicus effect on host
death due to paralysis from the larvae (larvae feeding for longer -> longer for toxins to be produced)
anaemia
irritation
reduced egg production
transmit: Boreelia anserina (tick fever) and Aegyptianella
Diagnosis is argus persicus
find larvae on birds
find adults in sheds
Treatment of arus persicus
Organophosphate spray
kerosene emulsion
Tampan ticks
Ornithodoros
What is this?
Ornithodoros gurneyi
Features of tampan ticks
live in sand
feed on any host
painful bite (feed quickly)
transmit q fever
Spinous ear tick features
Otobius megnini
in North America and Africa
free living adult
larvae and nymph live in ear
horse, cattle and dogs
recently found in WA
Features of Ixodes
Long palps
anal groove in front of anus - frown face
22 species in Aus
Transmit lyme disease in North America
What species of ixodes cause paralysis?
Ixodes holocyclus
Ixodes cornuates
What is this?
Ixodes - frown in front of anal groove
Features of Ixodes holocyclus
3 host tick
on native animals
18 month lifecycle
larvae and adults in spring
nymph in autumn
Ixodes holocyclus effect on host
all stages cause irritation and paralysis
sheep dog and cat most susceptible (1 female will kill a dog in hours)
Calves and foals also susceptible
Females engorge for 21 days
Pathogenesis of Ixodes holocyclus
ascending motor paralysis
signs after 5-6 days
intense vasoconstriction
die from paralysis of respiratory muscles
animals can develop immunity
Treatment of ixodes holocyclus
find and remove tick
acaricidal wash
hyperimmune serum
Other paralysis ticks in North America
Dermacentor variabilis and dermicentor adersoni
Distribution of ixodes holocyclus and cornuates
Features of rhipicephalus
anal groove behind anus (smile)
basis capituli projects
forked first coxa
Brown dog tick
what is is a vector of?
Ripicephalus sanguineus
Babesia canis
Identify this tick
Ripicephalus australis
Features of Ripicephalus australis
short palps with ridges
pale legs
female has ‘waist’
Lifecycle of ripicephalus australis
1 host tick
22 days
egg hatches
seed ticks climb grass and attch to passing cattle
larvae and nyphs on host
female drop off after 18-37 days (most 22 days) in the morning
Ripicephalus australis effect on host
irritation
damage hide (lose 25% of value)
anaemia
anorexia (reduced apetite)
Reduced growth rate and milk production
Transmit protozoans
Babesia, Anaplasma and Theileria
Weather conditions on Rhipicephalus australis
in
- southern limits
- dry tropics
- wet tropics
- cool winter (suppress development)
takes 3-4 generations to build up again over summer
- temp not limiting
dry winters
ticks increase in wet season
- temp never limiting
rain all months
ticks all year around
Dispersal and spread of rhipicephalus australia
larvae migrate 1m
can be blown 30m
can spell paddocks to control tick
in summer 50% live for 2 weeks
in winter 10% live for 4 weeks
can survive 11 weeks in cool weather
Resistance of rhipecephalis australis
Zebu most resistant
aquired immunity in all breeds
saliva in antigenic
hypersensitivity develops
resistance against feeding larvae
mast cells and basophils collect around hypostome->histamine released -> increases reflex grooming
larvae fed with histamine articicially will detach
Chemical control of Rhipicephalus Australis
Resistance developed to most
macrocytic lactones still used
Growth regulators - Flurazuron
Vaccine? Made against proteins of the gut epithelium of Rhipicephalus. Ticks that feed on this are exposed to antibody/complement attac on their epithelium.
They grow poorly and have low fecundity
70% effective and need 2 vaccines
controll program of rhipicephalus australis
6 dips at 21d interval or 4 pour on treatments at 35 day interval
Bush tick - features
Haemophysalis longicornis
common in SE Asia
Introduced to Aus, in eastern Aus
3 host tick
vector of babesia gibsoni in dogs
What is this tick?
Haemophysalis longicornis
What are these
Bothriocroton & Amblyomma
Long mouthparts
smile anal groove
brightly coloured
Host specific
Aus species occur on reptiles. Also one for wombat, echidna and kangaroo.
