Avoiding mozzies

By: Scott Heiman, Photography by: Scott Heiman


Stay alert but not alarmed of the ‘deadliest animal on earth’.

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You’ve finally arrived at your camp destination. You hop out of the vehicle and immediately cringe as you realise you’re not going to have the place to yourself. With the high-pitched buzzing of mosquitoes zinging around your ears, it won’t be a quiet night. The least that you’ll endure is the intermittent slapping of skin and yelps of irritation as your fellow campers take mozzie eradication into their own hands. Of more concern is the prospect of mosquito-borne diseases, as you ask yourself: "What did dad tell me about Dengue fever, encephalitis, Ross River virus and Barmah Forest virus?"

It’s enough to put you off your T-bone steak!

So how worried should we actually be about mozzies? In my view, the important thing is to be educated about the risks and to take proper preventative measures. To coin a popular phrase, I reckon it’s a matter of: "being alert, but not alarmed". 

NATURE’S FOOD SOURCE

Before we decide to wage devastation on this tiny invertebrate, it’s important to realise that mosquitoes play an important role in a variety of ecosystems. For example, in aquatic environments, mosquito larvae serve as a food source for fish. In other habitats, spiders, frogs, reptiles, and other insects eat them. More broadly, mozzies are an important and reliable food source for migratory birds. They also serve as pollinators as well. All this indicates that they actually are a significant part of the ecosystem and the uniqueness of the area is why we are holidaying there in the first place.

Not all mozzies are actually as big a pest as the itchy welts on your arm might lead you to believe. After all, there are around 3500 known species of mosquito worldwide, occupying every continent (except Antarctica, though there is a biting midge) – yet only around 200 species will annoy humans and even fewer will bite. In general terms, a mozzie’s diet consists of decaying leaves, organic debris, and microbes. Only female mozzies (not males) ‘drink’ blood – and only when they’re mating, because they need the extra protein. 

THE DEADLY ITCH

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Mosquito bites are itchy and uncomfortable, but they could lead to something much worse. The humble mozzie is a vector for certain diseases, some of which can be deadly. That is why the Bill Gates Foundation lists them as the ‘deadliest animal on earth’. We have all heard of malaria and we associate it with the tropics. But did you know that mosquitoes can also transmit incurable diseases in the south of our country, too?

Recently, we picked up a brochure on the way through South Australia titled ‘Fight the Bite’. It warned of serious diseases that are mosquito-borne for which there are currently no cure and no vaccine. The list included Ross River virus, Barmah Forest virus, Murray Valley encephalitis, Japanese encephalitis, Dengue and Chikungunya virus. The list looked like a game of scrabble.

That said, your chances of being infected with a disease through a mosquito bite are very small, but that doesn’t stop them from still being irritating.

However, if you have the sudden onset of high fever, severe joint pain (mainly in the arms and legs), headache, muscle pain, back pain, rash, drowsiness, confusion, nausea and vomiting, tremors or seizures, common sense says consult a doctor.

CHEMICAL WARFARE

We don’t know about you, but offering our blood to support the next generation of mozzies isn’t particularly appealing. So, inevitably, many of us turn to the retail market to find pre-prepared, chemical-derived options to deter the little suckers. And there are certainly some pretty potent products available.

  • DEET – We’ve long forgotten what the acronym DEET stands for. But most of us have seen this stuff listed as the active ingredient of popular mozzie repellents like Bushman. DEET is the product recommended by reputable agencies like the Army Malaria Institute, a world-recognised centre for malaria research and training. The trouble is that DEET can melt plastic when it comes into contact. That’s why you’ll find your fishing line and sunnies melted if Bushman bursts in your fishing tackle bag. While DEET’s been widely used and accepted for 60-plus years, it’s known to irritate eyes and, in intense doses, it can have some nasty neurological side effects. So we might want to think twice about slapping it around too liberally on our skin. 
  • Picaridin – This synthetic compound derives from the same plant genus (Piper) that produces table pepper. It’s generally regarded as being safer than DEET (for you and your kit) and it provides slightly longer protection. But Picaridin has been in the mozzie repellent field for a shorter period than DEET (about 25 years) so the long-term health risks haven’t been as fully tested. Products such as OFF! contain Picaridin.
  • IR3535 – The United States Centre for Disease Control and Prevention recommends using a mosquito repellent with the active ingredients Picaridin, DEET, IR3535, and Oil of Lemon Eucalyptus. The compound IR3535 is one I’d never previously heard of. It sounds like something that should be associated with a mad scientist. After a little research, we found out that – like DEET – this stuff can irritate our eyes and dissolve plastics. Unlike DEET, it’s not as effective in repelling mosquitoes that may carry yellow fever, dengue, and encephalitis.

GETTING BACK TO NATURE

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We were happy to see Oil of Lemon Eucalyptus in the recommended cocktail ingredients for manufactured mozzie repellents. This naturally-occurring extract has been found to be as effective as 15-20 per cent DEET against mozzies (but not effective against sand flies) and protection lasts up to six hours. You can find this stuff marketed as Citriodiol in some mozzie repellent products – or simply in bottles at your local chemist.  

But are eucalypt oils the only thing standing between us and melted sunglasses? An old surveyor told us once that he always swore by a diet of Vegemite and garlic to keep the bloodsuckers at bay. And if that didn’t work, he recommended a campfire smoking with green gum leaves and dry dung.

GIMMICKS AND GIZMOS

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If it sounds too good to be true, it probably is! The market abounds with traps, ultrasonic devices, smartphone apps and bracelets that all sound very appealing. In Canada, there is even a pill called Mozi-Q containing homeopathic dilutions! Unfortunately, there is little scientific evidence that any of these will protect you from mosquito bites.

We ran a little test of some natural products while out scrub in the south-east SA. And while wearing a DEET-free bracelet and a three-frequency ultrasonic ‘buzzer’, and sitting next to a citronella coil, the mosquitoes of Wellington, SA, were happily sitting on my arm next to the bracelet, sucking away (note, when travelling through here, you must stop at the Court House Café and try a ploughman’s pastie)!

In short, there is nothing you can eat, drink or strap on that has been scientifically proven to prevent mosquito bites. That’s right, not even vitamin B which blows Vegemite out of the water. Nor does spraying repellent into the air – you must apply it directly to the surface area.

Sitting around a campfire recently at a favourite spot, we thought we’d gauge the opinions of some other seasoned travellers. So we asked: "What products have you tried – what works and what doesn’t?" 

We got some pretty diverse answers…

  • Remove the core from a toilet roll and put the roll inside a coffee tin. Then half fill the tin with methylated spirits and top it up with citronella oil – just under the level of the top. Light the roll and it burns for hours – providing light and heat as well.
  • Mix in a sprayer: 2tbsp eucalyptus oil, 8tbsp Dettol, 2tbsp tea tree oil, 500ml water and a drop of liquid detergent. The spray’s good for me, dogs and chooks!
  • Go easy on the aftershaves and perfumes. These smells can attract mozzies. Mozzies also seem to be attracted to blue and dark coloured clothing as well as blonde hair.
  • Big doses of vitamin B help. It helps prevents some bites and limits the effects of those that get through.
  • Take the missus as they are more attracted to her than me.

WHAT ARE THE ODDS?

Have you ever been covered with itchy mosquito bites, only to have your friends innocently proclaim that they don’t have any? Well, you’re not alone. According to the Smithsonian, around 20 per cent of us are tastier than others for the little invertebrate.

You’ve joked about it but you may just not only taste better but smell better too! That is, research shows that the humble mozzies find certain blood types more appealing and that you secrete a chemical that indicates what blood type you are! People with type O blood are twice as likely to be bitten than type A, with type B falling somewhere in the middle.

Mozzies also locate their targets by locating carbon dioxide in your breath and larger people exhale more frequently and deeper over time. They can also smell uric and lactic acids as well as ammonia, all of which are in our sweat. Those that exercise more expel more and some are genetically disposed to expelling these waste products more often.

Body heat is also an attractant to some species of mozzie – those with a higher body temperature will attract more mozzies, with pregnant women twice as likely to be bitten because they are expelling more carbon dioxide and have a body temperature one degree higher on average. That explains why you get bitten on the neck.

Mozzies also have a complex eye and, as such, are attracted to movement and colours that stand out such as red and dark blue which are on the extremes of our colour range.

They also seem to be attracted to some types of bacteria than others then at the same time are repelled by more diverse bacteria build-ups. That explains why you get bitten on the ankles more often than places like the armpit.

ONE BITTEN, TWICE SHY

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Wherever you go across this fair country, the mozzies in one location seem to be immune to the repellent that worked 100km away. With that in mind we recommend ‘a little from column A, a little from column B’ simultaneously.

  • Cover your skin as much as you can when mosquitoes are active
  • Use an insect repellent on exposed skin and the brim of your hat
  • Make sure the screens and seals in your camper are secure and repair any rips and tears
  • Avoid camping near standing water
  • Then try also burning a coil or citronella product
  • Throw some green eucalypt leaves on the fire

IN THE END…

The next time you’re out camping, have a look around to see who is getting bitten more than others.

If the boffins are correct they will have type O blood; have a larger frame and be breathing, sweating or exercising more than usual; or pregnant; or wearing a dark blue or red shirt.

The full feature appeared in Caravan World #559. Subscribe today for the latest caravan reviews and news every month!