Control of Ticks on Livestock Flashcards
what are paralysis ticks
Salivary neurotoxins that are variably reversible cause progressive paralysis
Ixodes holocyclus toxin is similar to botulinum toxin
Karoo paralysis tick Ixodes rubicundus (Southern Africa)
Paralysis tick Ixodes holocyclus (Southeastern Australia)
American dog tick Dermacentor variabilis (USA)
Rocky Mountain wood tick Dermacentor andersoni (USA)
what diseases do ixodes ricinus cause
Babesia divergens
Anaplasma phagocytophilum
Staphylococcus aureus tick pyemia
Louping ill virus
Diverse rickettsiae
what dieseases do dermacentor reticulatus cause
Babesia spp
Anaplasma marginale
what diseases do Haemaphysalis longicornis cause (autralasia and asia pacific)
Theleria buffeli/orientalis and others
what diseases do Rhipicephalus microplus (Australasia & Asia Pacific)
Babesia bigemina
B bovis
A marginale
what diseases do Rhipicephalus microplus & R decoloratus (africa) cause
Babesia bigemina
B bovis
A marginale
what diseases do Amblyomma variegatum & A herbraeum cause (africa)
Ehrlichia rumination known as heartwater
what disease does
Rhipicephalus appendiculatus
cause
Theileria parva East-Coast-Fever (ECF)
how many hosts does I ricinus have and how long is the life cycle
3 host tick with 3 year life cycle
Hosts:
Larvae on small mammals, birds
Nymphs on rabbits
Adults on ruminants
what environmental conditions do I ricinus need
Need >90% humidity
Questing when >10ºC
Feeding activity peaks April & May in most of UK
In high rainfall areas there is feeding also in Aug and Nov
what is the most important species of tick globally
r microplus
what is R microplus distribution limited by
mean temp
need <4 months <16C and rainfall
what is the lifecycle of R microplus
1 host tick
18-35 days on single host
Range of total LC 42-300 days
3-5 generations per year
Host include cattle, horses, small ruminants, wild ungulates
what are the impacts of ecology of r microplus
Simple life cycle
Strategic control programmes relatively simple
High fecundity — potential for rapid and massive infestation
Single host lifecycle with potentially low refugia accelerates acaricide resistance
what are the impacts of ticks
TBD transmission
Reduced growth rates
Reduced production
Anemia
Tick worry pyoderma
Hide damage
what does host density have to do with tick control
No host no ticks
The extent to which wildlife hosts can maintain tick populations varies among species
Re-stocking after periods with few or no cattle will increase tick problems
what does host resistance have to do with control
Some breeds more resistant than others
what does temperature have to do with tick control
Low temperatures retard growth but don’t kill ticks unless temperatures are extreme
High temps shorten survival but accelerate development
Very high temperatures and low humidity are lethal to ticks
what does humidity have to do with tick control
Desiccation and inundation can both be lethal to ticks
Ticks will survive flooding and are dispersed widely by floods
Desiccation effects on the stage affected
what does vegetation have to do with tick control
Ticks make use of vegetation to find their hosts and also to protect themselves from direct sun
In the absence of vegetation, survival times of larvae are much reduced
what are the eradication requirements
- Continuously treat all possible hosts for the maximum period that free-living ticks can survive at intervals that are less than the minimum parasitic phase
* ex. R. microplus this means 6-8 treatments every 3 weeks during early summer - Strong legislation
- Full or regional compliance
- Effective acaricide
- Effective methods of application
what are the pros and cons of eradication
Pros: ends needs for treatment
Cons: rarely successful, if fails likely to increase resistance to acaricides, if successful, population susceptible to TBDs
what is reactive vs strategic control
Strategic control is sometimes confused by farmers and advisers with reactive, suppressive control or threshold control
A “suppressive” or “reactive approach” might be expected to result in farmers applying treatments at times corresponding with the yellow arrows
“Strategic” approach treatments are applied at predetermined times to maximize their impact on the total population of ticks on any given area of land
what are the major acaricide groups
Arsenic
Organochlorines (OC)
Organophosphorus (OP)
Carbamates
Synthetic pyrethroids (SP)
Macrocyclic lactones (ML)
Amidines
Insect acarine growth regulators
Phenylpyrazoles
