What are sandflies?
New Zealand doesn’t have many venomous or dangerous native creatures. But one that is a real nuisance is the tiny sandfly, a type of blackfly. Like blackflies elsewhere, they bite humans. The bites are very itchy, and often cause redness and swelling.
There are 13 native species, but only two of them bite: the New Zealand blackfly and the West Coast blackfly.
Where do they live?
They usually occur where there is bush and flowing water (where they breed). This includes rivers, beaches, and around lakes and swamps.
- The New Zealand blackfly lives in the North Island, and around the coasts of the South Island.
- The West Coast blackfly lives only in the South Island, where the West Coast and Fiordland are famous for their swarms of sandflies. Lots of people get bitten at Sandfly Point, on Fiordland’s Milford Track.
Sandflies are not usually found indoors.
Why do they bite?
Only the females bite – they need blood to produce eggs. They attack birds, cats and other animals, and humans.
When do they bite?
They are most active at dawn and at dusk. Because they can’t see at night, they don’t often bite in the dark.
New Zealand has 16 mosquito species – 12 are native (but only four of these bite). The others have come to New Zealand from overseas.
As with sandflies, only the female bites (the males feed mostly on flower nectar). But unlike sandflies, they fly into houses, and often attack at night when people are sleeping. They breed in still water, such as ponds or clogged drains.
Dealing with bites
To prevent bites, cover up well and use an insect repellent. Traditionally, Māori used crushed ngaio leaves to deter insects. Citronella candles also help keep bugs away.
Scratching only makes the bites worse. Relieve the itch and swelling with calamine lotion or antihistamine cream.
Overseas, blackflies and mosquitoes carry and spread diseases, but there are no records of them doing so in New Zealand. Some disease-carrying mosquito species, found at New Zealand ports, have been stopped from spreading into the country.