As summer heats up, these tiny “vampires” become more active - but they’re not all bad.
Dr Leilani Walker, curator of entomology, and Dr Melissa Kirk, associate curator of entomology at Auckland Museum have shared these insights into the bloodsuckers that call Aotearoa home.
Mosquitos
Mosquitos play a vital role in New Zealand’s ecosystems. Photo / Warren Buckland
New Zealand hosts 16 mosquito species, most of which are endemic.
Known as waeroa in te reo Māori, mosquitos play a vital role in Aotearoa’s ecosystems.
Notably, the vigilant mosquito (Culex pervigilans), is the most common mosquito and widely distributed endemic species in New Zealand.
While it rarely bites humans, its high-pitched buzzing can be a nuisance when it enters your home.
Introduced species like the striped mosquito (Aedes notoscriptus) and the southern house mosquito (Culex quinquefasciatus) are more inclined to bite humans.
Only female mosquitos eat blood, the protein and iron in the blood are used to produce eggs, whereas males eat plant nectar.
Currently, these mosquitos are not vectors for diseases such as malaria within New Zealand, however, with climate change, there’s an increased risk of exotic mosquito incursions and the diseases they may carry.
Interestingly, many native mosquitos within Aotearoa have evolved as bird specialists and can transmit avian malaria.
While they may be unwelcome in our homes, they are crucial to Aotearoa’s ecological balance.
Mosquitos and their larvae are a food source for many native species of fish, birds and other insects.
Male mosquitos, which feed on plant nectar, contribute to pollination.
Leeches
Most of New Zealand’s leeches aren’t after human blood. Photo / Sarah Ivey
Luckily, most of New Zealand’s leeches aren’t after human blood.
Leeches are segmented worms closely related to earthworms, and many in New Zealand are predators of freshwater invertebrates rather than blood-feeders.
The most common leeches are from the Glossiphoniidae family.
Glossiphoniidae mostly live in urban, slow-flowing, weedy streams and ponds. The most common native genus of freshwater leeches is the Alboglossiphonia: a small, light-coloured leech.
However, Aotearoa is home to one native species that does feed on blood – Richardsonianus mauianus.
Found in slow-flowing, weedy streams and lakes, it has been recorded in places like Oruarangi Creek in Māngere. Though capable of feeding on humans, it’s not very common.
Interestingly, Richardsonianus mauianus is still used in modern medicine.
Medicinal leech therapy, which dates back centuries, is used in hospitals today, particularly in microsurgery, to reduce coagulation and improve blood flow.
In New Zealand, a leech farm in Waikato breeds this species for medical use.
Ticks
The New Zealand cattle tick can affect many species of lifestyle animals. Photo / Virbac NZ
Ticks are arachnids, closely related to spiders and mites.
New Zealand has 10 recorded species of tick, each with unique feeding behaviours and host preferences.
Some ticks, known as hard ticks, attach themselves to their host for an extended period, gorging on blood until they drop off.
Others, known as soft ticks, take smaller, shorter blood meals over multiple feeding sessions.
We do have ticks that will bite people, as well as cattle, birds, and others. The good news is major tick-borne diseases, such as Lyme disease, are not present in New Zealand.
However, ticks are still capable of transmitting bacteria and viruses, meaning that if tick-borne diseases were ever introduced, they could potentially become a threat.
Many tick species are highly specialised to particular hosts.
For example, the tuatara tick (Archaeocroton sphenodonti), as its name suggests, feeds only on tuatara blood and lays its eggs in tuatara nests.
Because they only live where tuatara densities are high – and are often removed when tuatara are being prepared for translocations – they are even rarer than their hosts.
Another species (Ixodes anatis) known as the kiwi tick, mainly parasitises kiwi and lives in their burrows.
Despite their nuisance factor, sandflies play an important ecological role.
They breed in freshwater streams, and their larvae act as filter feeders, helping to clean the water and are vital to New Zealand’s freshwater ecosystems.
Discover more about blood-feeding creatures – and the legends they inspire – in the exhibition Bloodsuckers: Legends to Leeches, on at Auckland Museum until April 27.
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