Ticks Flashcards
How would you identify a hard tick?
Hard dorsal covering (Scutum–> the hard diff colour covering on back)
Prominent mouth parts
Festoons/or notches may be present
Ornate ticks have coloured patches
Festoons are the pie crust like structure on the edge of the scutum
Females don’t have a scutum
Hard tick wall convoluted blood meal—> so can expand and stretch outwards
How would you identify a soft tick?
Scutum is absent
Mouthparts- not visible from dorsal surface (i.e. when looking on top of tick)
Do not swell much (feed little but often)
Tick mouthparts:
Describe the different structures?
Palps: sensory organs
Chelicerae: these puncture the skin
Hypostome: tube for inserting into skin and sucking host blood has backward-pointing barbs to hold in place
Mouthparts are cemented into place–> which results in implication for removing them.
Ticks feed continuosly: what do the inject into the host to i mprove the feeding process?
Saliva contains inhibitors of blood coagulation and platelet aggregation, vasodilatory and immunodulatory substances
—> keeps blood flowing reduces host inflammation
Give the 4 names of the tick life cycle?
Egg laying
Larva (6-legs)
Nymphs (8 legs)
Adult tick (8 legs)
Whats the big difference when it comes to classifying soft ticks and hard ticks?
Number of hosts
Hard ticks can have 1, 2 or 3 hosts
Soft ticks often feed on many hosts
What is the tick population levels at different rainfalls in tropical environments?
Tick more active when more moist/humid so spring and autumn
Dependent on temperature and relative humidity
Tropical—-> no rainfall pattern—-> ticks population stays constant
Tropical with rainfall pattern—-> tick population jumps up and down
What is trans-stadial transmission?
Infectious agent (Lyme disease) ingested during feeding by larva and keeps infection as develops to adult
Passed on from one host to the next as tick develops
Not present onto the eggs
What is trans-ovarial transmission?
Infectious agent (e.g. Babesia spp.) is passed from one generation to the next through the egg
The most common Hard tick in the Uk is….., give facts about this tick.
Ixodes Ricinus
- Can be found world wide
- Wide host range- 3 host tick
- Life cycle: 3 years on average
- Ticks feed for a few days each year
- Most of the time- on the ground
- Can cause lyme disease
Vector for animal disease: boine babesiosis, louping ill (sheep), tickborne fever & tick pyaemia (ruminants)
Give 3 examples of hard ticks found oversease.
Dermacentor:
- 3 host tick
- Vectors for diseases:
Viral (colorado tick fever)
Rickettsial
Bacterial
Protozoal
Rhipicephalus:
- Warmer climates worldwide
- Vectors for Theileria parva
- Paralyisis in livestock
Boophilus spp.
1-host tick
Warmer climates worldwide, except Europe
Vectors for Babesia and anaplasma spp. in cattle
Give an example of a soft tick
Found in warmer climates
Argas spp.
infect birds (also humans)
A. persicus, puoltry tick- lives in revices in poultry houses
feeed at night-> production loss + death (large numbers)
Found on migratory birds in temperature regiosn
How do we control tick numbers?
- Kill ticks on ground
- By altering microclimate: pasture improvement
- By starving: ‘spelling’ pasture (livestock removed); useful only if ticks don’t feed on other animals
- By burning e.g. during dry period before rainy season
-Seperate host from infection: stock management removes stock from tick-infected areas when ticks are active, fencing off infected pastures - Kill ticks on host: Acaricides: dipping, spraying, pour on formulations
- Enhance host resistance: Stock hybridisation: humped breed x European breeds,
Heritability of resistance to ticks is higher in humped breed that European breeds
Enhance host resistance: vaccination now used in australia for boophilus micrcoplus control, raises Ab against hidden antigens in the ticks gut
What the difference between the action of the vaccine and the action of the acaricides/
Vaccine tackles the egg production/life cycle
Acaricides tackle the tick itself by killing it
