DOC warns of sandflies from Franz Josef to Abel Tasman. There's no disease risk.

Are there sandflies on the West Coast? Yes, and New Zealand's Department of Conservation (DOC) warns about them itself. Its page for Westland Tai Poutini National Park, which covers Franz Josef and Fox Glacier, says to bring insect repellent "as sandflies are prevalent," and its Abel Tasman Coast Track page says "There are wasps and sandflies." The CDC lists no insect-borne disease for New Zealand, and our New Zealand sandfly guide has the country overview.

Glaciers, roadside stops and the Coast Track

Near Fox Glacier, DOC's page for the Lake Matheson walk says "Sandflies can be fierce here." The glacier valley walks at Franz Josef and Fox lie in the same national park, so carry repellent on each one. Farther south on the Haast highway, the Knights Point lookout has a reputation as a sandfly stop. DOC's pages for Hokitika Gorge and for Paparoa National Park, home to the Pancake Rocks at Punakaiki, don't mention sandflies, though the coast's reputation makes repellent sensible there too.

On the Abel Tasman Coast Track, DOC recommends insect repellent for the sandflies. On the beaches, treat feet and ankles before you stop, especially late in the day.

The flies are black flies of the genus Austrosimulium. Only the females bite, and their larvae grow in flowing water, which a coast of rivers and streams supplies. Te Ara, the government's Encyclopedia of New Zealand, names the West Coast blackfly, Austrosimulium ungulatum, as one of the two species that bite people. They carry no disease in New Zealand, though in people who react strongly the bites can raise intensely itchy welts.

What helps: repellent, cover, timing

Sandflies bite in daylight and seldom in the dark, and by most accounts they are worst on warm, humid, still days. They tend to struggle in cold weather and bright sun, and they are slow fliers, so short stops help.

If you get bitten, try not to scratch. The CDC suggests hydrocortisone cream or calamine lotion for itchy bites. Our repellent timing guide shows when to reapply on a long day of short stops.

Where you're going

Here is how the main West Coast and Abel Tasman stops compare for a December–April trip.

Heading south to Fiordland? Our Milford Sound briefing covers the Milford Road, the Milford Track and Te Anau.

What travelers report

Paraphrased from TripAdvisor forum threads and linked so you can read them in full. Neither carries a year, and sandfly numbers change from day to day with the weather.

• West Coast · January

  Planning a mid-January choice between the West Coast and the Catlins, the poster asked about sandflies. A reply said West Coast sandflies are legendary and advised repellent, long sleeves and not scratching; another noted that the biting species carry no infectious disease. TripAdvisor ↗

• Abel Tasman (Bark Bay, Marahau) and South Island tracks

  On a four-week South Island trip the poster wore repellent and hiking clothes and got only about five bites over several days of hiking, at Bark Bay in Abel Tasman, where the insects were a nuisance on the beach. Replies said sandflies thrive in warm, humid weather but struggle in cold or bright sun, are slow fliers so short stops help, and are mainly a daytime problem; one described bad bites on the feet at dusk in Marahau. TripAdvisor ↗

The usual end-of-trip rule still applies. Any fever during or after your trip means a doctor visit, and you tell them where you traveled, especially if New Zealand was one stop on a longer trip through the tropics.

Traveler questions