10 Tips to Avoid Sandfly Bites in New Zealand

It’s not your imagination, New Zealand genuinely has a lot of sandflies. More than many countries, and certainly more than any of us wish for. There are a few reasons for this:

1. Our landscape is perfect for them

Sandflies thrive in environments with clean, fast-moving water. Rivers, streams, waterfalls, wetlands, and shaded forest edges are their ideal breeding habitat. New Zealand just happens to be full of all of these things.

2. Our climate is mild

Unlike mosquitoes that prefer warm, muggy climates, sandflies in New Zealand are active across a wider range of temperatures. They remain energetic in cooler weather and can be found year-round in some areas.

3. Limited predators

New Zealand has relatively few native animal species that feed on adult sandflies. While larvae are eaten by fish and other aquatic life, there isn’t enough predation to keep sandfly populations low.

4. Humans keep showing up where they live

Sandflies are most active in the exact areas where we love to tramp, camp, fish, hunt, and explore. To them, we’re just well-placed food with backpacks.

What’s the Purpose of Sandflies (and Why Can’t We Just Eradicate Them)?

It’s tempting to imagine a sandfly-free New Zealand, but sandflies actually play important ecological roles, annoying as they may be.

1. They’re a food source for native creatures

Both larvae and adults serve as meals for birds, fish, spiders, and other insects. Removing sandflies would disrupt several layers of the food web.

2. Their larvae help keep rivers clean

Sandfly larvae feed on algae and decomposing organic matter, helping to filter and maintain the natural balance in freshwater ecosystems.

3. They’re part of New Zealand’s natural heritage

New Zealand has 19 species of native sandfly and only two are known to bite humans. They’ve been here long before people arrived, and they play a role in maintaining the health of their ecosystems.

So why can’t we eradicate them?

Getting rid of sandflies would mean damaging waterways, harming native species, interfering with ecosystems—and taking away food sources from animals that depend on them. The environmental cost would be far worse than the itching.

So instead of dreaming of their extinction, we focus on smart prevention.

These strategies are used by hunters, hikers, river-crossers, hut-hoppers, and anyone else who’s ever made the mistake of standing still on the West Coast.

1. Use a Strong Repellent (Natural or DEET)

Repellent is your first and best line of defence. But choosing the right one matters.

DEET Repellents

• Pros: Highly effective, long-lasting, ideal for high-density sandfly zones.

• Cons: Can melt plastics, damage synthetic fabrics, and degrade waterproof coatings. Strong chemical smell.

• Best for: Fiordland, Stewart Island, Arthur’s Pass, the West Coast, and any place where sandflies come in clouds.

Natural Repellents

These often use citronella, geranium, eucalyptus, tea tree, neem, lavender, or a blend.

• Pros: Gentler on skin, gear-friendly, more pleasant scent, safer around young kids.

• Cons: Need frequent reapplication and are less effective in heavy sandfly pressure.

• Best for: Day walks, beaches, low-sandfly areas, short breaks.

2. Cover Up With Lightweight, Long-Sleeve Clothing

Sandflies can’t bite through fabric, so give them as little exposed skin as possible.

• Wear long-sleeve shirts, long pants, and tight-weave fabrics.

• Choose light-coloured clothing—sandflies are more drawn to dark colours.

• Add a buff, hood, or light gloves in sandfly-dense areas.

• Avoid loose cuffs or gaps—they’ll crawl right under.

3. Keep Moving (Sandflies Love Still Targets)

Sandflies are slow, weak fliers. If you’re moving, you’re winning.

• Keep walking when possible, especially near rivers and bush edges.

• If you need to pause, stop in breezy or exposed spots where they struggle to land.

• Avoid hovering around gear, food bags, or boots—they love the CO₂ and warmth.

4. Choose Campsites Carefully

Where you pitch your tent can decide whether you enjoy your evening or spend it smacking your own legs repeatedly.

Avoid:

• Edges of rivers, streams, and river flats

• Damp, shaded bush edges

• Boggy areas or wet grass

Choose instead:

• Breezy ridges

• Open clearings

• Higher elevation sites

• Sunny, exposed ground

Also:

• Keep your tent zipped shut at all times.

• Shake out clothing and gear before bringing it inside.

• Choose a tent with quality insect mesh, especially for summer trips.

5. Travel in Shoulder or Off-Peak Season

Sandflies are most intense during the warmer, wetter months—generally October through March.

If your schedule allows, choose:

• Early spring missions

• Late autumn trips

• Cooler, breezy days

You’ll get beautiful landscapes with far fewer winged vampires.

6. Avoid Sitting Right Next to Water

It’s tempting to plonk yourself down beside a river or lake for lunch, but that’s sandfly headquarters.

Sandflies breed near water. They swarm near water. They live for water.

Instead:

• Sit on higher, drier ground.

• Move just 10–20 metres away from the riverbank. It makes a massive difference.

• Avoid standing still in damp or mossy areas where they congregate.

7. Leverage Wind and Dry Conditions to Your Advantage

Sandflies absolutely hate wind. Even a gentle breeze can disrupt them.

• Choose windy or exposed spots for breaks.

• Pick campsites with natural airflow.

• Dry off quickly after river crossings—wet skin attracts them.

• Sweat also draws them in, so pace yourself during steep climbs.

8. Head for the Mountains (Sandflies Hate Altitude)

Sandflies prefer low elevations, dense vegetation, and moist habitats. Once you break above the bushline into sub-alpine and alpine zones, sandfly numbers drop dramatically.

Why?

• Colder temperatures

• Stronger winds

• Less shelter

• Poor breeding habitat

9. Chase the Sun

Just like vampires, sandflies don’t like sunlight. Where possible, seek out a sunny spot when you stop for lunch. Some brave soldiers may still risk sunlight exposure for a taste of your blood, but there will usually be much fewer sandflies bothering you.

Be warned, as soon as a cloud blocks the sun – they’ll be back.

10. Try an Anecdotal Remedy (If You’re Desperate Enough)

Every Kiwi tramper has a story about the secret trick that “totally works against sandflies.”

• Vitamin B tablets

• Garlic

• Marmite

• Rubbing yourself with lavender

• Eating more salty food.

There’s no scientific evidence to support these claims. But some people swear by them, and when you're desperate, you’ll try anything, right?

Even the best-prepared adventurer will get nipped eventually. Here’s how to deal with the itch and prevent further irritation.

1. Resist the urge to scratch

Scratching releases more histamine, which intensifies the itching and increases the risk of infection. Sandfly bites can turn into nasty sores if scratched open repeatedly.

2. Wash the area

Use cool, soapy water or a gentle antiseptic wipe. This helps remove saliva and reduces inflammation.

3. Apply an anti-itch treatment

Good options include:

• Hydrocortisone cream

• Calamine lotion

• Aloe vera gel

• Antihistamine cream

• Tea tree oil (diluted)

• Cold compress or ice pack

These soothe the skin, calm the immune response, and reduce swelling.

4. Take oral antihistamines

A great option for people who welt up severely, or when you have multiple bites at once.

5. Watch for signs of infection

If a bite becomes warm, red, or increasingly painful, particularly after scratching, get medical advice.

Do sandflies bite through clothing?

No. But they will crawl under loose hems or gaps, so secure your cuffs and tuck layers in where possible.

Are sandfly bites dangerous?

They’re mostly harmless but can become infected if scratched excessively. Some people react more strongly, experiencing swelling and heat.

When are sandflies most active?

Early morning, late afternoon, cloudy days, and anywhere near water. They’re less active in bright sun, wind, and cold.

Do only female sandflies bite?

Yes. Females need the protein from blood to develop their eggs. Males are too busy sipping nectar to bother anyone.

Is DEET safe to use?

Yes, when used as directed. Higher concentrations last longer but aren’t necessarily more effective. Avoid getting DEET on your gear as it can damage plastics, waterproof coatings and synthetic fabrics. Apply carefully.

Are there sandfly-free places in New Zealand?

Yes. High alpine zones are usually sandfly-free, and many open, windy ridges have very few.

Do natural sandfly repellents actually work?

Yes, some natural sandfly repellents work, particularly those containing oil of lemon eucalyptus or specific essential oil blends, but they are generally less effective and require more frequent reapplication than DEET-based products. However, they are better for your health and the environment, so it depends on what’s most important to you.