Eights Things to Love About Australian Mosquitoes

This is a guest post by Dr Cameron Webb. 

Love Australian wildlife? Fascinated by their ability to adapt to our diverse, often hard but incredibly unique habitats? Let me introduce to you the champions of adaptation, the humble, but often extremely annoying, mosquito.

There are hundreds of different mosquitoes in Australia. Some of them are locals, some of them are shared with our neighbours in South-East Asia and the Pacific, while others have accompanied travelers to our shores over the past couple of centuries. From coastal rock pools to alpine snow melt creeks, mozzies have found a home in almost every pool, pond and puddle across the country.

They’re a diverse group of creatures. Their life cycle is split in two with about a third of their life spent as wrigglers then pupae in the water, and the remaining two to three weeks as adults buzzing about and on the lookout for blood. But it’s only the females that bite. The blood provides an energy boost for egg development. The blokes mate and not much else - they’re lucky to live more than a week or so.

Image: Stephen Doggett

Image: Stephen Doggett

The need for blood means they bite us. Annoying enough as the biting can be, the possibility that these bites can make us sick is a major concern. Australia is generally free of the really nasty mosquito-borne diseases such as malaria, Japanese encephalitis and Zika, but we do see occasional local cases of dengue and our home-grown viruses, particularly Ross River virus and Barmah Forest virus causing around 5,000 cases of illness each year.

But they’re not just pests. Mosquitoes hold a fascinating place in our local environment. Here are either things to love (or at least begrudgingly respect) about mosquitoes!

1. They can fly a long way! While many of our backyard mosquitoes don’t fly much further than our neighbour's place, those in our coastal wetlands have been reported flying more than 20km inland. Scientists who mark these mozzies with fluorescent dusts have tracked their movements over many kilometres.

2. Salty water or fresh - no problem! While most mosquitoes love freshwater, some of Australia’s most common mosquitoes love living in saltmarshes and mangroves that are flooded by high tides. The saltier the water, the better it is for these mosquitoes. It’s just a shame we’ve got to share the coast with them. 

3. Mozzies are snack food for bats! Many have asked what “good” a mosquito could possibly do and scientists answered this recently by studying the diet of microbats. These small insectivorous bats prefer to eat moths than mozzies but that doesn’t mean they don’t chomp through plenty each summer. Mosquitoes may not have much more nutritional value than a fingernail but if you eat enough of them, they’ll provide a boost in energy. Just don’t expect bats to control mosquito populations - it won’t happen.

4. Surviving a decade of drought! Mosquito eggs are amazing. While many hatch quickly once laid, others can survive for months or years, remaining unhatched inside water-holding containers and in cracks and crevices around our local wetlands. A decade of drought ravaging our waterways across inland regions of the country wasn’t enough to kill off these mosquitoes, and following the flooding of the past couple of years, they have re-emerged in record numbers.

5. Crabs in your bed? No worries! There are some mosquitoes in northern Australia that have moved into crab holes along the coast. These water-filled muddy holes are perfect for escaping the ebb and flow of daily tides and probably provide a neat hiding place from hungry fish.

6. Bright orange and far from boring! Most mosquitoes are probably considered drab but many are adorned with bright, iridescent scales and elaborate patterning. But the most beautiful are some of the bright orange mosquitoes that are so distinctly different that they stand out like a beacon amongst others.

7. Mozzies are home to harmless viruses! While we’re concerned about mosquito-borne pathogens that pose a risk to human health, scientists are now discovering a world of viruses living in mosquitoes that pose no risk to humans. These ‘insect specific viruses’ live in the mosquito and, one day, may even be able to help stop the spread of more serious viruses through their use as a 'mozzie vaccine', as when they’re present, they can block other viruses from infecting the mosquito.

8. Yum, let's suck up some ant vomit! Feeding on blood may make you feel icky enough but how about ant vomit? There is a mosquito in northern Australia that’s adapted to sticking its proboscis down the throats of ants instead of into the arms of people. The ants escape unharmed but the mozzies escape with a sweet meal.

You can purchase a copy of Cameron's book by following this link.

Dr Cameron Webb is a Medical Entomologist with NSW Health Pathology and University of Sydney. He is lead author of A Guide to Mosquitoes of Australia (CSIRO Publishing) and can be followed on Twitter (@mozziebites) for all the tips and tricks on avoiding mosquito bites this summer!

Banner image courtesy of Stephen Doggett. 

This article has been co-published by Wild Melbourne and Andrew Isles Natural History Books.

A Buzz In The Night: The Unknown World of the Mosquito

I’ve had a real interest in unravelling the ecological role of mosquitoes and raising awareness of mosquitoes as a diverse, fascinating and beautiful part of the Australian environment.

One of the co-authors of the recently released A Guide to Mosquitoes of Australia, Dr Cameron Webb is an advocate for understanding the often demonised insect that is the mosquito. With many native species calling Australia home, this new guide from CSIRO Publishing reveals more fascinating facts about these creatures than you’d ever expect. Having recently been given the chance to chat with Cameron about his new book, I can safely say that I am eager to learn more and more about what many would call the world’s most annoying (and deadly) pest.

It was whilst exploring north-east Australia that renowned botanist Joseph Banks took note of the large numbers of mosquitoes to be found along the coast. Other European explorers also found it hard to ignore the ‘nuisance-biting’ of these insects, and it’s easy to see how such a perspective has continued to the present day. To hear the incessant buzzing of an elusive mozzie on the roof of your bedroom is perhaps one of the most frustrating things about Australia’s summer months.

But according to Cameron, ‘…Even if they do occasionally bite us, … we need to have a little more respect for their ability to find a home in such a diverse range of ecological niches.’ Mosquitoes can be found throughout a huge variety of Australian habitats, ‘from coastal rockpools to alpine snowmelt streams and from polluted drains to pristine wetlands’; they are not simply invaders of our home and garden.

Whilst there is yet to be a species identified that relies exclusively on mosquitoes, Cameron explains that ‘birds, bats, fish and frogs all eat mosquitoes’ – although ‘they’re probably more of a snack food’ than a primary source of sustenance. There is also evidence to suggest that these insects may play a role in plant pollination.  

Sometimes it is important to shift your perspective. We may perceive insects as pests because they’re abundant but to our local wildlife, that just means there are more of them to eat!

However, these are aspects of mosquito ecology that perhaps don’t come to mind when we see the result of diseases such as malaria, Zika virus, and dengue fever. As much as Cameron wants people to see the beautiful side of the mozzie, he is well aware of the immense danger posed by some species when it comes to the spread of mosquito-borne disease. This, he explains, was one of the main reasons for the development of the field guide: so that both sides of the picture could be explored. Cameron and co-authors Stephen Doggett and Richard Russell explain that several million people die every year from pathogens transmitted by mosquitoes, this fact alone making them the deadliest animal on Earth.  

Nevertheless, there are only around 12 species out of over 300 in Australia that have the potential to cause health issues. In many cases where Australians have been infected with serious mosquito-borne diseases, it is often the result of travellers coming into contact with species overseas or (very rarely) from an exotic species that has made its way into the country via plane – often referred to as ‘airport dengue’ or ‘airport malaria’.

One fascinating section of the guide’s introduction describes how mosquitoes nearly lost the war for Australia during World War Two – that is, because so many troops in New Guinea were suffering and dying from malaria. In fact, the presence of Aussie troops in countries where malaria was endemic actually highlighted the need for better research into mosquito biology in the first place. For example, the ‘Land Headquarters Medical Research Unit’ was established in Queensland in 1943 due to the aforementioned effect that malaria was having on soldiers fighting the war.

Whilst the guide explains how to reduce the dangers of mosquito-borne disease through avoidance, protective clothing, and repellent, there are also plenty of interesting facts that have nothing to do with bites or disease at all. In fact, not all mosquitos bite humans (some prefer the taste of birds, reptiles and frogs). For the species that do, it is actually only the females that bite, using the acquired nutrition to complete the development of their eggs. And did you know that some mosquitoes don’t consume blood at all? So there is a whole world of mosquito behaviour to discover that is completely separate to the experiences of us humans. 

Additionally, although invasive mosquito species pose serious threats to humans in Australia, a perhaps less understood impact is the effects that they might have on our own native mosquito species. Cameron describes how ‘the locals and newcomers would mostly share…habitats’, the larger issue being that exotic mosquitoes ‘would dramatically change the landscape of nuisance-biting and public health risks from our swamps to the suburbs’.

And what about the potential effects of global warming? Cameron explains that ‘we’re probably unlikely to see any major shifts in geographic distribution or seasonality in pest and public health risks directly due to a changing climate.’ It is more so the ‘indirect things’ that will have an impact on mosquito populations into the future, such as ‘urbanisation and environmental rehabilitation’ exposing more humans to Australian mozzies, and globalisation increasing the amount of foreign species arriving on our shores, along with the pathogens that they carry.

Image: Stephen Doggett

Image: Stephen Doggett

As well as the detailed yet easily digestible information provided, the outstanding photography, primarily contributed by Stephen Doggett, is also something to be admired. Cameron believes that ever-improving photographic technology and the general public’s access to social media have encouraged a higher appreciation of the misjudged and the miniature through fascinating imagery. With a section titled ‘Beauty in mosquitoes’, one major focus of this book is the aesthetic side of these species that we don’t often consider – and the photos certainly do capture the allure of the Australian mosquito in all its understated glory.

It is made clear in this field guide that mosquitoes are another of Australia’s animals that are often taken for granted and treated only as pest species, rather than natives. Whilst the dangers of mosquito-borne disease are indeed very real, it is important to remember that in most ecosystems containing mammals, birds, fish and plants – there is most likely an organism as small (and infuriating) as a mosquito that plays its own unique role as well.

This book belongs on your bookshelf if… ‘you get a buzz out of Australia’s fascinating insects, or at least just want to beat the bite of mozzies in your own backyard!’

Head to the CSIRO Publishing website to purchase a copy of the field guide.  

Rachel Fetherston

Rachel Fetherston is an Arts and Science graduate who is passionate about communicating the importance of the natural world through literature. She recently completed her Honours year in Literary Studies, involving research into environmental philosophy and the significance of the non-human other. She is the Arts and Philosophy Editor for Wild Melbourne.

Find her on Twitter at @RJFether.

Banner image courtesy of Stephen Doggett.