Does New Zealand Have Ticks? And What to Do About Them

New Zealand does have ticks, though the situation looks quite different from countries like Australia or the United States. The country’s tick fauna is small, with only a handful of species, and the risks they pose fall mainly on livestock and wildlife rather than on people. The most widespread and economically damaging species is an introduced cattle tick that arrived from East Asia, while a few native tick species quietly parasitize birds. For visitors and residents alike, the practical picture is reassuring on the human-health front but more complicated for farmers and conservationists.

Which Ticks Live in New Zealand

New Zealand’s tick diversity is modest compared with most other temperate countries. The species that matter break down into two broad groups: a small set of native ticks associated with birds, and one introduced species that has become a serious agricultural pest.

The best-known native tick is Ixodes anatis, commonly called the kiwi tick. As the name suggests, it feeds primarily on kiwi, and it has drawn attention because of its association with threatened kiwi species.¹ Another native species, Ixodes uriae, is a seabird tick found across circumpolar regions. In New Zealand it parasitizes penguins and other colonial seabirds. Researchers studying Ixodes uriae globally have identified at least 16 RNA viruses carried by this tick, seven of them previously unknown, including members of several major virus families.² These viruses are of scientific interest, but they circulate in seabird colonies and are not a meaningful risk to people or domestic animals.

The introduced species that dominates the picture is Haemaphysalis longicornis, the Asian longhorned tick, also called the New Zealand cattle tick. It is the only tick in New Zealand that infests livestock, and its economic significance has grown sharply in the past decade.³ Originally from East Asia, H. longicornis established itself in New Zealand’s North Island and parts of the upper South Island. It has since spread to other countries including the United States, where it was first detected in 2017.

The Asian Longhorned Tick and Why It Thrives

One reason H. longicornis is so successful at colonizing new environments is a reproductive trick: females can reproduce without mating. This ability, called parthenogenesis, means a single female carried on an animal or in imported goods can start an entirely new population.⁴ Combined with the tick’s tolerance for a wide range of temperatures and its ability to feed on cattle, deer, sheep, and other animals, parthenogenesis helps explain why the species has become so firmly entrenched.

That said, H. longicornis does have environmental limits. It thrives in moist, warm-temperate conditions, and larvae in particular are vulnerable to drying out. The tick can develop at temperatures from roughly 12°C up to nearly 40°C, but dehydration rather than cold is what most constrains where it can survive.³ In practice, that means the tick is most at home in the warmer, wetter parts of the North Island. Drier inland regions and much of the South Island have historically been less hospitable.

The Theileria Outbreak and What It Meant for Farmers

For decades, New Zealand’s cattle tick was considered a nuisance that reduced animal condition and caused some production losses, but it was not regarded as a vector of major disease. That changed abruptly in August 2012, when an epidemic of bovine anaemia linked to a blood parasite called Theileria orientalis Ikeda type broke out in cattle herds.⁵ The parasite is transmitted by the cattle tick, and because New Zealand had no other pathogenic tick-borne blood parasites of cattle, researchers could study the effects of this infection without the confounding influence of co-infections common in other countries.

The scale of the initial outbreak was serious. Data from nearly 200 affected farms covering about 100,000 cattle showed that roughly 2,850 animals developed clinical disease and around 590 died. The case fatality rate across those farms was estimated at about one in six, though the impact varied enormously from farm to farm. A subset of 22 farms were hit especially hard, with clinical disease and death rates both exceeding five percent of the herd.⁶

Longer-term follow-up on affected dairy farms painted a somewhat more optimistic picture for animals that survived the acute phase. Average infection levels during the milking season were generally low, and once cows moved into the chronic, carrier stage of infection, the effect on milk production and reproduction appeared minimal.⁷ On one farm in the study, however, newly infected cows still showed measurable milk losses compared with uninfected herd mates, and cows sick enough to need treatment with the drug buparvaquone lost even more. The takeaway for farmers is that the initial infection wave is the dangerous period; animals that recover tend to cope well, but the acute phase can be devastating.

Do New Zealand Ticks Bite People

They can, but in practice it is uncommon. Haemaphysalis longicornis has been recorded biting humans in other parts of its range, though it overwhelmingly prefers animal hosts. Hikers, farmers, and outdoor workers in tick-prone areas of the North Island occasionally find one attached, but New Zealand does not have the kind of tick-borne disease burden that makes human bites a public-health emergency in places like the northeastern United States or parts of Europe.

New Zealand has no established cycle of Lyme disease. The spirochete bacteria that cause Lyme disease depend on specific tick species and reservoir hosts that are not present in the country. Similarly, the rickettsial diseases and viral encephalitides transmitted by ticks in North America, Europe, and Australia have not been identified as circulating in New Zealand’s tick populations.

One tick-related condition that has drawn global attention in recent years is alpha-gal syndrome, an allergy to red meat and other mammalian products that develops after certain tick bites. The condition is triggered by immune responses to a sugar molecule introduced through the tick’s saliva.⁸ Alpha-gal syndrome has been linked primarily to Amblyomma americanum (the lone star tick) in North America and Ixodes holocyclus (the paralysis tick) in Australia, neither of which is established in New Zealand. Whether H. longicornis bites can trigger it is less clear, and the condition has not emerged as a recognized problem in New Zealand to date.

How to Remove a Tick if You Find One on Yourself

If you do find a tick attached to your skin in New Zealand, the principles of removal are the same worldwide. The goal is to pull the tick out intact, without squeezing its body in a way that could push saliva or gut contents into the bite wound. Fine-tipped tweezers or a purpose-made tick-removal tool are the standard approach: grasp the tick as close to the skin surface as possible and pull steadily upward without twisting or jerking.

An alternative technique that has been described in the literature involves using a thin implement like a wooden stick or the end of a match to apply gentle rotating movements against the tick’s mouthparts, which can disengage the tick. Proponents of this rotation method report success in dozens of cases.⁹ Whatever method you use, avoid folk remedies like burning the tick with a match, smothering it in petroleum jelly, or applying nail polish. These approaches either do not work or can cause the tick to regurgitate into the wound, which is exactly what you are trying to prevent.

After removal, clean the bite area with antiseptic and keep an eye on it for a few days. In New Zealand’s context, the risk of tick-borne infection from a single bite is very low, but redness, swelling, or flu-like symptoms in the days following a bite are worth having a doctor check.

Climate Change and the Expanding Tick Map

New Zealand’s tick picture is not static. Climate projections suggest that warmer, wetter conditions in some regions could expand the areas where H. longicornis can thrive. Modelling of the tick’s habitat suitability under future climate scenarios projects slight to moderate increases in suitability across much of the South Island. For certain South Island regions, including the West Coast, Marlborough, Tasman, and Nelson, those increases in environmental suitability could translate into a higher proportion of cattle farms falling within the tick’s viable range.¹⁰

The effects cut both ways depending on local conditions. Regions that become warmer and wetter are expected to see more cattle tick activity and potentially more flystrike, while regions that become warmer and drier may actually see fewer ectoparasites of all types.¹¹ The reason goes back to the tick’s sensitivity to dehydration: heat alone is not enough to support the tick if moisture levels drop below what larvae can tolerate.

For farmers in currently tick-free parts of the South Island, this means the situation bears watching. A region that has never needed a tick-management plan might need one within a few decades, and the arrival of ticks would bring the risk of Theileria along with them.

The Biosecurity Threat from Exotic Ticks

Beyond the species already present, New Zealand’s biosecurity agencies are alert to the risk of new tick species arriving. One species that has received detailed risk assessment is Amblyomma americanum, the lone star tick of North America. Ecological niche modelling found that New Zealand’s climate could support this tick across a geographic range broadly similar to the current distribution of H. longicornis, and possibly even more extensive.¹² The lone star tick is an aggressive biter of humans, a known vector of several diseases, and the primary tick linked to alpha-gal syndrome in the United States. Its establishment in New Zealand would substantially change the human health equation.

Under climate change projections out to 2050, the modelling predicted only moderate increases in habitat suitability for the lone star tick, mainly along mountain valleys in the South Island.¹² Still, the conclusion was unambiguous: given the opportunity, this tick could establish and spread, and it could serve as another vector for theileriosis in cattle on top of whatever direct harm it caused to humans. Border surveillance for exotic tick species on imported animals and goods remains one of New Zealand’s most important lines of defence.

Managing Ticks on Farms

For New Zealand cattle and deer farmers, tick management revolves around acaricides, or chemical tick-killing treatments. The good news is that so far there is no evidence of acaricide resistance in H. longicornis in New Zealand. The most commonly used active ingredient against the cattle tick is flumethrin, a synthetic pyrethroid, and experience with this compound in Japan suggests the tick is likely to remain susceptible in the near term.¹³ That said, resistance is an ever-present evolutionary risk when chemicals are used heavily. Researchers recommend judicious and targeted use of acaricides, integrated pest management approaches, and maintaining what parasitologists call “refugia,” essentially leaving some of the tick population unexposed to treatment so that susceptible genes stay in the gene pool.

Pasture management offers another angle. Research on a different cattle tick species in South America has shown that resting pastures from grazing for defined periods can reduce tick larvae waiting in the grass. The required spelling period depends on the season: starting a rest period in spring or early summer allows a shorter break than starting in autumn or winter, because warmer conditions speed up the tick’s off-host lifecycle and cause larvae to exhaust their energy reserves faster.¹⁴ While that research was conducted on a different tick species in a different country, the principle of pasture spelling as part of an integrated tick control strategy applies broadly, and New Zealand farmers working with their vets can adapt the concept to local conditions.

Protecting Pets

Dogs and cats in New Zealand are occasionally found with ticks, particularly dogs that accompany their owners onto farmland or into bush areas in the North Island. Haemaphysalis longicornis will feed on dogs, and heavy infestations can cause irritation and, in small animals, anaemia. The native bird ticks are far less likely to end up on a pet, though it is not impossible in areas where kiwi or seabirds are present.

Standard tick-prevention products available for pets in other countries, such as spot-on treatments, oral preventatives, and tick collars, work against H. longicornis. If you live in or visit a tick-prone area, using one of these products during the warmer months when ticks are most active is a reasonable precaution. Check your dog after walks through long grass, paying particular attention to the ears, between the toes, and around the face. Cats that roam outdoors can also pick up ticks, though they are generally more efficient self-groomers and less often heavily infested.

Ticks and Native Wildlife Conservation

While livestock impacts get the most attention, ticks also matter for New Zealand’s conservation efforts. The kiwi tick, Ixodes anatis, is of direct concern because of its close relationship with kiwi species, all of which are under some degree of threat.¹ Heavy tick burdens could stress individual birds and potentially serve as vectors for pathogens, though the ecology of disease transmission between ticks and kiwi is still poorly understood. Because kiwi populations are small and geographically fragmented, even a modest additional stressor can matter.

Seabird ticks raise a parallel set of questions. The virome work on Ixodes uriae revealed a rich community of viruses circulating in seabird tick populations worldwide, including at sites in New Zealand waters.² Whether any of these viruses cause disease in the seabirds themselves, or whether they might spill over into other species if conditions changed, are open questions. For now, seabird ticks operate largely out of sight in remote colonies, but they are a reminder that New Zealand’s tick story extends well beyond the farm gate.