Flies in Australia: All You Need to Know for a Bug-free Adventure

Australia is known for its diverse wildlife, and the world of insects is no exception. Among the many creatures that call this continent home, flies are a common sight for locals and tourists alike.

With their large eyes and ability to fly, these insects have adapted well to various environments, playing important roles in both the ecosystem and the lives of humans.

In order to understand the presence of flies in Australia, it’s essential to recognize their various species and the roles they play.

For instance, many adult flies in the Diptera order can appear similar to bees or wasps and even mimic their behaviors.

Some fly species are predators, feeding on pests such as aphids and scales, and providing biological control in gardens.

Different fly species also display unique characteristics, making them easily identifiable.

House flies, for example, are less than 3/8 inch in length and showcase four dark stripes on their thorax.

By understanding the diverse world of flies in Australia, people can appreciate their complex roles within the country’s ecosystems and perhaps learn to coexist in harmony with these unsung heroes of the insect world.

Flies in Australia: A Diverse Ecosystem

Fly Species and Their Roles

Australia boasts a diverse range of fly species, with over 30,000 identified members of the Diptera order.

Flies play critical roles in the ecosystem, from pollination to controlling pest populations.

For instance, the Bush fly is a common Australian species known for hovering around humans and livestock.

Despite being a nuisance, it helps break down organic waste.

On the other hand, mayflies are important food sources for native wildlife due to their short lifespan and abundance.

Some notable flies in Australia:

• Bush fly
• Mayflies
• Hovering flies

Pollination and Ecosystem Support

Flies are essential to the Australian ecosystem, providing pollination services similar to bees.

They feed on nectar and help pollinate flowers by transferring pollen on their hairy bodies from one flower to another.

However, some flies, like mosquitoes, can transmit diseases like dengue fever.

Their larvae develop in water, making stagnant pools and wet areas breeding grounds for these pests.

Features of pollination flies:

• Hairy bodies
• Feed on nectar
• Pollinate flowers

Characteristics of pest flies (e.g., mosquitoes):

• Transmit diseases
• Larvae develop in water
• Breeding grounds in stagnant pools

Comparison Table: Fly Species in Australia

Fly Species	Role in Ecosystem	Lifespan	Associated Problems
Bush Fly	Organic waste breakdown	Short	Nuisance to humans and livestock
Mayflies	Food source for wildlife	Short	None
Mosquitoes	Pollination	Short	Disease transmission

In conclusion, flies play crucial roles in Australia’s ecosystems. They participate in pollination processes and help maintain a balanced ecosystem.

However, some fly species can raise concerns regarding human health and nuisance.

Keeping habitats clean and addressing stagnant water sources can help minimize their negative impact.

Identification and Anatomical Features

Size and Body Structure

Flies in Australia, like the native Musca vetustissima, generally have a size ranging from 1/8 to 1 inch (4-25 mm) long.

Their bodies consist of a prominent head, thorax, and abdomen. Some distinctive features of flies include:

• Large compound eyes
• Distinct antennae
• Robust to slender body

Wings

Most Australian flies possess a pair of functional wings, designed for agile flight. Key points on their wings are:

• Single pair of membranous wings
• Hind wings are reduced to small balance organs called halteres

Eyes

Flies have compound eyes, which provide them with a wide field of vision and excellent motion detection. These eyes consist of:

• Thousands of tiny lenses called ommatidia
• Widely spaced on the head for a near 360° view

Mouthparts

Australian flies exhibit a variety of mouthparts, each adapted to their specific feeding habits. For instance:

• some species have sponging mouthparts, ideal for ingesting liquid food
• biting flies possess piercing and sucking mouthparts for feeding on blood

Features	Example	Purpose
Sponging mouthparts	Musca vetustissima (Australian house fly)	Ingesting liquid food
Piercing & sucking	Black flies	Feeding on blood

Behavior and Habits

Feeding Patterns

Flies have diverse feeding habits, depending on the species. Some are attracted to rotting organic matter, while others prefer sugar-rich substances.

For example, fruit flies breed in fruit and feed on yeasts that grow on organic matter.

• House flies: attracted to decaying vegetable matter, rotting meat, or garbage
• Fruit flies: breed in fruit and feed on yeasts

Sweat and Human Interaction

Some flies, like sweat flies, are attracted to human sweat due to the salts and moisture present.

These flies can be a nuisance and may even potentially cause health concerns if they come in contact with open wounds.

Examples of interaction:

• Landing on skin to obtain sweat
• Buzzing around exposed food during picnics or outdoor activities

Comparison table of common flies’ feeding habits and human interaction:

Fly Type	Feeding Habits	Human Interaction
House flies	Decaying vegetable matter, rotting meat, garbage	Annoyance, potential vector of diseases
Fruit flies	Breeding in fruit, feeding on yeasts	Contaminators of food, annoyance

Conclusion

Overall, Flies are ubiquitous and diverse insects that are found in almost every habitat and climate in Australia, where they play various roles as pollinators, decomposers, predators, parasites, and vectors of diseases.

They can be beneficial or harmful to humans and other animals, depending on the species and situation. Flies are fascinating and important animals that reflect the richness and complexity of life in Australia.

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about flies in Australia.

Scroll down to have a look at some of them.

Letter 1 – Flightless Fly allegedly from England is Australian Soldier Fly

Subject: What is this?
Location: England, uk
April 10, 2015 5:52 am
Just wondering what this is and if it’s harmless? Thank you
Signature: Kelly

Dear Kelly,
For now, we are calling this by the oxymoronic name of flightless Fly.  We are certain it is in the order Diptera, but beyond that, we cannot say at this time. 

It does not appear to be the flightless Crane Fly Epidapus venaticus that we found pictured on the Earth Life Web Fly Page as the antennae are quite different from the linked drawing.  We are going to seek some other opinions.

Chen Young provides some information
Hi Daniel,
Your doubt has its merit, this is not a crane fly and I don’t know off hand who she is.  I will need to ask my colleague about this one.  Could you provide me with the information as where this lady is from? 

Please double check with your source, my friend does not believe that this fly has an European origin.
Thanks,
Chen

Hi Daniel,
My colleague Dr. Martin Hauser from California Department of Food and Agriculture has identified your wingless fly as a primitive soldier fly Boreoides subulatus  (family  Stratiomyidae) from Australia, and they are found only in Australia. 

Perhaps your source did not understand the importance of locality of the bugs when come to identification.

I have done a little more checking around and noticed that you had a webpage about this wingless fly.  They might look slight different but I think it is caused by the camera angle and lighting effect.
2010/04/03/mystery-of-the-month-mating-flies-from-australia/
Thanks,
Chen

Thanks so much for the response Chen.  We will try to get some verification from Kelly regarding the location of the sighting, and also if anyone in the area recently returned from Australia.

Eric Eaton Concurs
Gentlemen:
I looked this up online myself and came to the same conclusion as Martin Hauser, but did not reply because of the locality being the UK rather than Australia.
Eric
author, Kaufman Field Guide to Insects of North America
http://bugeric.blogspot.com/

Letter 2 – Mating Australian Flies

What are these bugs?
Hi – I took these pictures a few months ago with a Canon MP-E 65mm lens and MT-24EX flash. Actual size is about 6mm long?

When in flight they appear to hover, not at all like the usual flies around here (Melbourne, Australia)
Adam

Hi Adam,
Identifying Flies is not our strong point, and we don’t even want to venture a guess at an Australian species. Your photos rock bigtime. Eric Eaton weighed in with this information:

“The mating Australian flies are likely something in the family Platysomatidae, or the closely-related Otitidae (sometimes referred to as Ulidiidae). I know, clear as mud! Don’t blame me, I don’t make the taxonomic rules.”.

Letter 3 – Mystery of the Month: Mating Flies from Australia

Australian bug mating in Autumn
April 3, 2010
This pair of bugs is defying my attempts to identify them, The picture was taken in Eastern Australia south of Sydney in early autumn.

There were many similar mating pairs visible. The female is 1 inch long and appears to have no wings. the male is winged but much smaller.
Bruce Terry, Sydney, Australia
Southern Highlands, NSW, Australia

Dear Bruce,
Had your photo arrived two days earlier, our first reaction would have been that someone was playing a very good April Fool’s Day joke on us and we would have searched for evidence of photoshop tampering. 

Our second thought was that this might be an accidental encounter between unrelated species, but the magnification revealed penetration barely visible under the wings of the male.  Your written account of the sighting also discounts the accidental encounter between unrelated species possibility. 

These are flies, and there are species of flies that are wingless, but we don’t know of a species with such pronounced sexual dimorphism in which only the female is wingless. 

This may take us hours of research that we could otherwise spend answering the increasing number of letters we are beginning to receive now that spring has arrived in the northern hemisphere. 

We have opted for posting without an identification, leaving it as an announcement at the top of our homepage until we get a response with a correct identification.  Karl has returned from Costa Rica and he is wonderful at internet research.  Have you any additional photos from other angles?

Back in January 2007, we posted a photo from Australia of a Wingless Fly that was identified as a female Boreoides subulatus in the subfamily Chiromyzinae and this is probably the same subfamily, so we will be creating a new fly subcategory now that there are two postings on our site.

Dear Daniel, Thank you for your very prompt response, and for the star billing on the website!

I attach another photo (not exactly the same bug, that one had disappeared) but the same species, this time with no attendant male.
It shows more clearly the foreparts which might help with identification.
Thank you for your help with this.
Best regards
Bruce Terry

Hi again Bruce,
Thanks so much for the high quality additional photo.  This should assist any Diptera experts that view our site.

Update:
April 4, 2010
Mirth provided us with a comment, though the link did not show.  We did a web search of the information she provided, and we found this Csiro website.

Letter 4 – Australian Fly

What Fly is this?
Location: Thirroul NSW Australia
January 3, 2011 9:41 pm
Hi Bugmen,
I have had a good look at the CSIRO site which is a little lacking & ozanimals.com which is a little more helpful however I have not been able to locate an image of a similar fly to assist with identification.

Image taken in the warm temperate rainforests behind Thirroul on the South Coast of NSW Australia, elevation of about 200meters above sea level. The fly was about the size of a Vinegar Fly (Drosophilidae)
Signature: Standard

Dear Standard,
This is sure an unusual Fly, but we do not know what family to begin searching.  Have you tried the Insects of Brisbane website?  Perhaps one of our readers will be able to supply an identification.

Letter 5 – Unknown Australian “Fly” might be female Yellow Headed Parasitic Snail Blow Fly

Subject:  What Is this wierd fly?
Geographic location of the bug:  Nsw, Sydney, Australia
Date: 12/19/2017
Time: 07:09 PM EDT
It has yellow spots on one side, and a sliver green surface (like a fly) on the other side.its overall shape is that of a fly, But the head is in the form of a wasp with it being yellow.

It also has the wings of the fly. Overall, It is also prettt big, and It looks like a hybrid of a fly and a wasp. What is it?
How you want your letter signed:  S.A

Dear S.A.,
Alas, your image is far too blurry for us to identify, but we are posting it.  Perhaps one of our readers will take a stab at an identification.

Update:  We can’t believe Cesar Crash provided what seems to be an excellent possibility:  a female Yellow Headed Parasitic Snail Blow Fly that is pictured on Brisbane Insects.

Letter 6 – Unknown Flies found on the tail of a Kangaroo in Australia

Subject:  Insect Identification REquest
Geographic location of the bug:  Erowal Bay, New South Wales, Australia
Date: 10/25/2021
Time: 09:42 AM EDT
Your letter to the bugman:  I photographed these insects on a fully grown adult Eastern Grey Kangaroo’s tail, in February, 2020. Do you have any idea what they are, please?
How you want your letter signed:  Nick

Hi Nick,
Other than believing that these are Flies in the order Diptera, we have not had any luck with further identifications, but we can’t resist posting your adorable image of a group of Eastern Grey Kangaroos.  We hope to investigate this further.

Letter 7 – Unknown Mutilated Wingless Australian Fly is actually a wingless female Chiromyzinae species

Australian bug
Hi
These pictures are of a bug which was found in my courtyard in the Blue Mountains, Australia. It was only about 2 cm in length.

I have been trying to keep a record of the different wildlife which live in my backyard, something which started last year as a school project, but have been unsuccessful in identifying this creature. Can you help? Best Wishes
Petah

Hi Petah,
We have tried to identify this Wingless Fly, but sadly, we had no luck. We are checking if Eric Eaton has any clues.

Here is Eric’s revelation: “I have no idea what the wingless fly is, but it would appear it once ‘did’ have wings, and they were torn off at some point. That is a pity, as wing venation patterns are of the greatest help in identifying flies!”

Update: (09/20/2007) forwarded through Eric Eaton
I have a second question, how to get in contact with the people from “Whats that bug”? They had a pic of a Unknown Mutilated Wingless Australian Fly (01/13/2007) Australian bug And this turns out to be a Stratiomyidae, Boreoides subulatus, the females are always wingsless and it looks not even close to something we know here in the USA as a strat.

It is out of the strange subfamily Chiromyzinae and this is an only Southern continent group. Only one species is introduced to Cal as a pest… So maybe you can email the people and give them the answer to their question.

Also further down they have an Acrocerid as a Bombyliidae and a suspected “Mallota” which is a Merodon equestris. Looking forward to see your book! Cheers
martin