Sandflies! They’re a hot topic across New Zealand, particularly in the backcountry when you just want to enjoy being out in nature where everything is peaceful.
Because when the sandflies start to bite, you can’t help but notice them…then they inevitably become a topic of conversation. Ugh.
So here’s a post answering popular questions about sandflies.
I hope you learn some interesting facts about sandflies (as will I) to spice up your next sandfly conversation.
TABLE OF CONTENTS
1. Where in New Zealand do sandflies live?
2. What do sandflies look like?
3. Are there different types of sandflies?
4. Why are they called sandflies?
5. Are there any Maori legends based around Sandflies?
6. What’s the story with sandfly bites?
7. How do you avoid getting bitten?
8. How do you treat sandfly bites?
NEW ZEALAND SANDFLIES: QUESTIONS/ANSWERS/FACTS
Getting a photo of sandflies is hard…so here’s a photo of Milford Sound. A place where they thrive.
1. Where in New Zealand do sandflies live?
Sandflies breed and live in fast-flowing streams, where they go from egg to emerging adult.
With a love of water, sandflies thrive in areas where the water is running and humidity is high. The perfect conditions for them are warm overcast, lower pressure days when humidity is high.
You’ll rarely find them above 1000metres above sea level.
2. What do sandflies look like?
Sandflies are tiny, black insects. There are lots of species of sandflies, but the three species that bite in NZ look identical (2-3mm long).
3. Are there different types of sand flies?
Yes. There are 19 species of sandflies in New Zealand, most of them have a 20-40 day life cycle.
Three of the 19 bite humans:
- The New Zealand blackfly (Austrosimulium australense). It’s found in coastal areas on the South Island and widely around the North Island.
- You’ll need to be in the South Island if you’re looking for the West Coast blackfly (A. ungulatum)
- And while not large in number, you can find A. tillyardianum on both islands.
None of the three NZ biting species transmit diseases to humans (some overseas species do), but they can affect birds by transmitting ‘avian malaria’.
4. Why are they called sandflies?
Captain James Cook has the honour of dubbing them sandflies, which is what he called them when exploring Dusky Sound in 1773. He noted:
“The most mischievous animal here is the small black sandfly, which are exceedingly numerous, wherever they light they cause a swelling and such intolerable itching that it is not possible to refrain from scratching and at last ends in ulcers like the small pox.”
5. Are there any Maori legends based around Sandflies?
Why yes, I’m glad you asked 😉
The most common Maori legend is about how sandflies were created. It goes like this.
Tu Te Rakiwhanoa had just finished carving out the beautiful region, Fiordland and said:
“It’s so beautiful, people will here forever. I will create the sandfly – to remind them of their fragility and death.”
She got us good there!
Another legend relates to Hinenui-te-Po, who lived up to her bitchy goddess reputation and released sandflies into Milford Sound to keep people away from the gorgeous region.
Or there’s the legend that they were created to punish laziness. One of the ways to avoid getting bitten by sandflies is to keep moving, so that does work!
And to finish this section, according to legend, the sandflies were able to bring dead hero Ha-tupatu back to life.
Random fact: The Maori word for sandfly is namu which is the same word for female genitals.
6. What’s the story with sandfly bites?
The male is harmless! They’re essentially vegetarians. The bloodsucking females are the ones who’ll getcha, as they need a feed of blood before they lay eggs. Also worth mentioning, their prime feeding time is dawn and dusk.
When they’re not feasting on humans, they’ll happily go for birds and other mammals. From bats to cattle and a whole lot more. Apparently, they really like penguins…even more so than humans.
Why are sandfly bites itchy?
When sandflies are biting us, they’re using their tiny TINY claws and mouth to stretch the skin, before tearing through it and accessing our blood. The anticoagulant in their saliva then encourages the blood to the wound site. The histamine is causing the itch.
Weirdly, it’s us that releases the histamines. It’s our body’s immune response to saliva. Histamines release fluid in the area you’re bitten which is why sometimes you’ll find swelling around bites.
The fluid helps by diluting the saliva and flushing it away. Interestingly, when the body detects histamines, some nerves will fire repeatedly which in short are telling the brain that the site is itchy.
Random fact: Sandflies swarm. Scientists have shown they can bite up to 1000 times. An hour! Eeek.
7. How do you avoid getting bitten?
Hiding from New Zealand sandflies isn’t easy…they find us because of our smell, colour, shape, and temperature. When they get within 6 metres of us, they switch to visual mode, aiming for the perfect place to land (almost like a pilot).
And because they don’t bite cold surfaces, they’ll stick to our warm bodies.
Sandflies tend to be attracted to dark clothing. So:
- Make sure you wear light colours
- Encouage your friends to wear black 😉
There are some other best practices to avoid sandflies too:
- When you’re stationary, cover up as much exposed skin as possible. Particularly ankles, feet and wherever blood vessels are close to the surface.
- Use an insect repellent (I’ll mention DEET further below).
- Burn a citronella candle.
- Take vitamin B pills which can boost your immunity to reaction.
- When you take a break from hiking, the best chance to avoid sandflies is finding a spot in the middle of a boring cleared field area.
Heavy rain or strong gusty winds give you a chance. Another important tip is to make sure you always leave your car windows and doors shut when driving through sandfly territory otherwise your vehicle will fill with the biting bastards. You’ll only make that mistake once.
What’s the story with DEET?
DEET is an ingredient found in lots of insect repellents since its first use cases in the 1940s. The yellow oil protects the skins against sandflies. While there are lots of different types of ingredients, many will say that unless it’s 40%+ DEEET, it won’t work against sand flies. Then you’ve got to remember it’s not exactly a natural remedy.
What is the best sandfly repellent?
Well, you’ll ideally need something with DEET in it. But there are lots of natural remedies available these days, including the popular Goodbye Sandfly.
Over the years, the following have been used to deter sandflies:
- crushed ngaio leaves
- orange peel
- citrus juice
- lavender
- baking soda
- toothpaste
- eating marmite (because of the vitamin B)
- tea tree oil
- vinegar
Random fact: Carbon dioxide is the sandfly equivalent to freshly baked cookies.
8. How do you treat sandfly bites?
If you’ve got a few bites, you can use an antihistamine cream or calamine lotion on the affected area to relieve the itchiness (ice can work too). If you’ve got a bigger reaction, you might want an antihistamine pill.
The best, yet toughest thing you can do with itchy bites is to not itch them (good luck with that). When you itch them, you risk the skin being broken and the risk of secondary infection becomes a possibility.
Apparently, urine can work too…but good luck dealing with any bites on your face. That or you’ll want to know your friend well. Very well :p
When you’re bitten by a sandfly, the bite can hang around for a couple of days (in most cases), but some people who have a severe reaction might have it hanging around for a few weeks. Those who are living in New Zealand tend to react less severely compared to visitors.
And there we go. Hopefully, some of these facts about sandflies can spice up our conversation, or at least give you a few tricks up your sleeve the next time you have to deal with sandflies.
If you’ve got any fun sandfly stories drop them in the comments below 🙂
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Hey, it’s Jub here. I’m the guy behind Chur New Zealand, helping you have the best time hiking, trekking, walking…whatever you want to call it…in NZ. I’m based in Queenstown and am always out and about exploring trails, old & new. If you have any questions, reach out.