Lecture 8 & 9 Arachnids: Ixodidae (ticks) Flashcards
Label the 5 parts.
What are the taxonomic family names for soft and hard ticks called? What is the major anatomical difference between the two?
Argasidae = soft
Ixodidae = hard - have a SCUTUM
In females of Ixodidae, which part of the tick is capable of expanding?
The idiosoma
The mouthparts of the tick are composed of a single ____ flanked by two ___ which function to guide it. The hypostome has two ______ projecting from the rostral border which cut the skin.
The mouthparts of the tick are composed of a single hypostome flanked by two palps which function to guide it. The hypostome has two chelicerae projecting from the rostral border which cut the skin.
Draw a posterior vs. anterior anal groove. Which one do ticks of the genus Ixodes have?
Is this tick male or female? Name the Family it is from. What is the arrow pointing to?
Male - big scutum
Pointing to the eye
Is Ixodidae; legs and capitulum are visible from dorsal vew.
How do ticks respire? Where is this structure located?
Spiracles
Located toward the posterior, near where the legs join the idiosoma
Label the four structures.
Nymph and adult ticks quest for hosts. How do larval ticks find a host?
They attach to a passing mammalian host with sticky forelimbs. Larvae link together so many will be dragged along with a single attached larva, and all attach at once.
Name one tick species which has this general life cycle.
Rhiphicephalus australis (Ixoididae)
For two-host ticks, which host (first or second) does the nymph get its bloodmeal to moult into an adult?
First.
Name two tick species with this general life cycle.
Ixodes holocyclus
Haemaphysalis longicornis (bush tick)
Which tick family has this life cycle? name a specific species.
Argasidae
e.g Argas persicus
What is the major difference between the life cycles of Argasidae and Ixodidae family members?
Argasidae have 2 or more nymphal stages
What is the Family this tick belongs to? Which species of this family is important to the AU poultry industry?
Argasidae
Argas persicus
You are called to a free-range poultry farm near Adelaide. You are greeted with this sight.
What is:
a) cause of death of these chickens
b) likely agent involved
c) possible consequences for the surviving stock
d) treatment or control options for the farmer
a: paralysis
b: Argus persicus
c: may be infected with Borrelie anserina or Aegyptianella pullorum
d: If bad infestation, can’t continue using pen
Otherwise, OPs and kerosene emulsion
Name to species of this genera in Australia. What is their life cycle (how many hosts) and what is their main veterinary concern?
Ixodes: I. holocyclus and I. cornuatus
3 host tick
Paralysis via holotoxin
You are working as a veterinarian in Cairns, far north QLD. A client comes in with their dog and a tick she has found attached to him. She is worried about tick paralysis.
a) what Family, genus and species is it? Is it native to Australia? How did you know?
b) What health complications might her dog now experience?
c) What kind of prevention can she use in the future?
a) Ixodidae > Rhipicephalus sanguineus. Introduced. Has forked first coxa PLUS lateral projections of basis capituli PLUS posterior anal groove.
b) Not a paralysis tick but is a vector for Babesia canis (intracellular parasite of RBC)
c) Should wear a Seresto (imidacloprid + flumethrin) collar or have Bravecto (fluorolaner)
A beef farmer visits your practice near Darwin with her dog. She is concerned about this tick she has found on the dog. It is a working dog and is out with the cows often.
a) what Family, genus and species is this? How do you know?
b) Is the dog the normal host?
c) Do you have any recommendations for the farmer concerning her dog and her cows?
a) Rhipicephalus australis - has shorter palps than hypostome, and palps have ridges. Anal groove is posterior (not seen here).
b) No - is a single-host parasite of cattle usually. Farmer should check her cows for this.
c) May live for up to 11 weeks in the environment depending on the weather so farmer is best off rotating her cattle AND commencing prevention - vaccination (x2) plus chemicals: oral growth regulators (flurazuron) & macrocyclic lactones. Should rotate chemicals in future to prevent resistance. Could consider buying in resistant cattle genetics next joining e.g Zebu. Cattle should be tested for blood parasites Babesia, Anaplasma and Theileria.
Dog should get Bravecto and be tested for blood parasites.
You find this tick on your dog after a work trip to Warnambool.
a) What genus and species is it? What morphological features did you use?
b) is it introduced or native? is it common in Victoria?
c) What health implications are there for your dog?
a) Projections from palps + prominent festoons + posterior anal groove = Haemaphysalis longicornis (a.k.a bush tick)
b) Introduced but common in VIC
c) Vector for Babesia gibsoni
Two ticks.
Name the genus of each of these. What is the main morphological feature that you can use to distinguish them?
On the left is Rhipicephalus - has lateral projections of the basis capituli
On the right is Haemaphysalis - has lateral projections of the palps
