Ticksawareness, managementand controlTicks adversely affect livestock production.Controlling tick infestations requires attention topasture management, insecticide use, andappropriate animal husbandry.

The problemTicks are blood-feeding animals related to mites

and spiders, and occur worldwide. Only one

speciei of tick occurs on livestock in this

cbuntry, the so-called New Zealand cattle tick,Hoemaphysalis longicornis. It is most coilrmonin North Auckland, the North Island east coast as

far south as Hastings, and on the west coast as

far south as Waikanae. It has been recorded inthe central North Island around Taupo, NationalPark and Taumarunui, and in the Golden Bayarea of the South Island. The tick is mainly apest of sheep, cattle and deer, but will attach toind feed from all classes of livestock, as well as

various wild mammals and birds.

SymptomsTicks cause damage when their mouth parts

enter the host's skin. While feeding, the tickinjects saliva into the host, causing a variety ofunfavourable reactions, but helping the tick toobtain blood. These reactions, together withblood loss, adversely affect livestockproductMty. Death may occasionally occur. TheNew Zealand cattle tick also transmits a micro-organism (Theileria orientalis), but this does notcause disease ofany concern.

Life cycleHaemaphysalis longicornis is a three-host tick.Each of its three active feeding stages - larva,

nymph and adult (females only, there are no

males in this species) - use a separate host on

which to feed. These can be hosts of the same ordifferent species. Depending on temperature and

other factors, such as host experience of ticks,

the feeding period can range from 4 to 7 days orlonger. The replete ticks detach and fall to theground where, if larvae or nymphs, they seek

shelter and, weeks or months later, develop tonext stage. The engorged females do not moult

but deposit many hundreds of eggs from whichlarvae eventually hatch.

RecommendationsTicks can be difficult to control. They spend a

lot of time offthe host and, when on the host, donot move much, which limits their contact withinsecticides. In addition, tick generations overlapand tick numbers in pasture are often large. Thisgives a continuous and substantial challenge tolivestock between late July and April, which puts

severe pressure on chemical prevention methods.

Pasture managementTicks spend about 80% of their lives in pasture.

Poorly drained pasture with rushes is oftenassociated with high tick numbers. Long pasture,

even in well-drained areas, will also harbourticks, but by improving drainage and keepingpasture topped or grazed, humidity in the swardwill be kept down, making conditions less

favourable for tick eggs to hatch or for engorged

ticks to moult. Topping and burning rushes does

kill some ticks but has little effect on eggs,

which later hatch. Ticks can survive for about a

year without a blood meal, so leaving pasture

ungrazed is not a viable tick control method.

Heavy grazing using cattle and older sheep toalmost eat pasture out and "pug" it will also

reduce tick numbers considerably. Use thistechnique sparingly so that only small areas ofthe farm are treated at any one time to allowregrowth.

Animal managementLittle can be done to make livestock less

attractive to ticks, or to remove ticks, except bychemical means. Dairy farmers have been knownto pick off all the ticks they can see when stockcome in for milking. This is not always practicalfor other livestock species.

Shorn sheep are more prone to whole-bodyinfestation with ticks than are woolly sheep. The

latter are usually infested only about the face,

axillae and groin. October to December iscritical as female ticks are most prevalent andprecautions to reduce the effects of this largest

stage will benefit stock.

ChemicalsApplying insecticides to pasture is a regularfeature of pasture-pest control programmes, and

in recent years has been proposed for tickcontrol. Widespread insecticide use, when moreenvironmentally acceptable measures are

available, is not readily justifiable.Only a few dips have label claims for tickcontrol. These are applied either as saturationdips (shower or plunge) or as pour-ons. Fieldexperience has shown that insecticides used

against ticks are much less persistent than whenused against other ectoparasites.

Dip persistence on cattle is very short comparedwith sheep, and repeat treatments may be

needed. Many deer farmers find spot treatmentof fawns can be successful. The animals are

carefully approached in their hides in the grass

and given a dose of insecticide in the ears, a site

where ticks are most commonly found.

Vacuum cleaningA combination of pasture and animalmanagement, and insecticide use, is a practicalmeans of reducing tick numbers. The technique,known as "vacuum cleaning", involves grazingstock (preferably older animals) on tick-infestedpasture for up to 3 days. This period is critical as

it gives ticks time to attach, but not to completetheir feeding, and then drop off back into thepasture. Infested stock are then treated in a

plunge or shower dip and replaced on the same

pasture with another mob of undipped animals.

By systematically working over one "bad"paddock at a time, and by introducing as many

mobs of animals as necessary, ticks will be

depleted" The number of mobs needed dependson how many ticks are seen after the first two ortl' ee graz\ngs. There is little point in continuingif animals have only a small number of ticks.The paddock is left ungrazed for about 4 weeks

and the "vacuum cleaning" repeated to remove

any remaining ticks.

Alternative hostsGoats, hares, rabbits, and a variety of other smallanimals and birds, are hosts to ticks and help

their spread. The importance of such animalsshould be considered in any tick controlprogramme and appropriate measures taken.

SummaryCombine all facets of tick control strategiesusing the separate calendar as a guide (AgFACTno. 3l: Tick control - farm calendar).

o Pasture management coupled with vacuumcleaning

r Vacuum cleaning coupled with insecticideuse and animal husbandry

o Alternative host control

Exotic ticksFrom time to time, ticks from other countriesenter New Zealand, either on humans or pets orin luggage. The two most common are the browndog tich Rhipicephalus sanguineus, and theparalysis tick, Ixofu s holocyclus.

The brown dog tick could survive anywhere inNew Zealand if confined to houses, wheretemperatures are higher than out of doors. It is amajor pest of dogs, but can attach to and feed

from a wide variety of mammals and is a vector,or potential vector, of many diseases. Theparalysis tick is more likely to survive out ofdoors in moist, warm areas and can feed from a

wide range of hosts. It can cause paralysis ordeath. Dogs and humans can become very sickand horses have been known to die as a result ofonly a few of these ticks being present.

Advise your nearest AgResearch or MAF officeor veterinarian of any unusual ticks"

For further information, contact :

Allen HeathAgResearchWallaceville Animal Research CentrePO Box 40063, Upper HuttPhone (04) 528 6089 Fm (04) 528 1i80

Although this document has been prepmed in good faith from amrmber of sources believed to be reliable, AgResearch does notgive any warranty that all information contained is accurate orcomplete or that advice given will be appropriate in all

circumstances. AgResearch shafl not be liable to anyone inrespect of any damages su{Iered as a result of their reliance on

the information contained in this document. Mention of product

trade names implies neither endorsement of those products norcriticism of similar products not mentioned.OAgResearch 1999. All rights reserved. Any reproduction of thisdocument in any medium without the consent of AgResearch is

/ fil^d aA /- -- -r rnnn

Tick control - farm calendarfor use with AgFACT no. 30: Ticks

Month Status oftick MonthControl measure

July First few nymphs on stock

Nymphal peak

Many nymphs still about

Nymphs onthe waneAdultticks appearing

Adults in large numbers

Adult peak

Larvae appearing

Larval peak

Last few larvae on stock

Nl,rnphs and some adults

Quiescent on pasture

(Overwintering period)

Stage

LawaeNymphsAdults

Months for dipping

January-FebruaryAugust-SeptemberNovember-December

Start season's contol progftLmmes by spraying stock in late

July to contol ovenrintered stages.

Dipping not practicable during lambing but dip all other stockwhere possible.

Spray docked lanrbs. Keep grass growth down. Cut downrushes and remove debris.

Spray or graze new rush growth. Keep down rank grass.

Dip all stock to kill adult ticks before eggs are laid.

Dip all stock to kill adult ticks before eggs are laid.

Dip all stock. Keep pasture short.

Dip all stock (but better done in January).Keep pasture short.

Graze out rough feed in pastures.

Cut down rushes and remove or bum debris.

Pasture management if practicable.

Pasture management if practicable.

Optimum time to control each stage of the tick

August

September

October

November

December

January

February

March

April

May

June

Although this document has been prepared in good faith from a number of sources believed to be reliable, AgResearchdoes not give any warranty that all information contained is accurate or complete or that advice given will be appropriate

in all circumstances. AgResearch shall not be liable to anyone in respect of any damages suffered as a result of theirreliance on the information contained in this document. Mention of product trade names implies neither elrdorsement of

those products nor criticism of similar products not mentioned.@AgResearch 1995. All rights reserved. Any reproduction of this document in any medium without the consent of

;h is strictly prohibited.

AgFACT no. 3 I, November I 995ISSN 1172-2088