As the days lengthen and temperatures climb, we are greeted by a familiar chorus of buzzing sounds. It’s fly season again.
But with almost a million species worldwide and some 30,000 inhabiting Australia, the (exceptionally) warm weather is also an opportunity to appreciate these remarkable and essential insects with which we share our world.
Despite their great diversity, we will likely encounter only a few selected flies daily. So who are these curious insects and how should we think about their presence in our lives?
Bush flies (Musca vetustissima) are the iconic Australian fly and are found throughout the country. They quench their thirst through the sweat and tears of mammals and thus linger around our heads, shoulders and faces in search of a refreshing drink.
They are so persistent that they are credited with inspiring the “Hello Australian“. These little explorers are otherwise harmless and pose no serious threat to health or the home beyond being a mild nuisance.
Similar in appearance are house flies (Domestic musca), who frequent our homes. However, unlike bush flies, they are more interested in food scraps and waste left unprotected. They regurgitate digestive juices to break down solids into a mush more suitable for their straw-like mouths, and may pose a minor hygiene problem as a result.
Flesh flies bring a little sparkle to the world of flies and are easily recognizable by their often large and shiny bodies. Although they are sometimes pests, they are also voracious scavengers and effective pollinators. In this way, they help break down organic matter, recycle nutrients, and transport pollen to support plant life.
The very size of horseflies making them powerful fliers, which can often be heard and seen at a distance. Females require a blood meal and therefore provide a hearty bite to mammals, including ourselves, and can be a nuisance to livestock. But they are also excellent pollinators, with some orchids relying on their hard work and specialized mouthparts to survive.
Finally, and most famously, are mosquitoes. (Yes, it’s a type of fly.) Many summer evenings are spent swatting females while they sip our blood.
More serious is their role as vector of diseases which have helped overthrow empiresand which remain a significant health burden, particularly in countries in the South. Malaria is among the most ambitious, while Ross River virus, chikungunya, zika And dengue fever all circulate with the help of mosquitoes.
You fly ?
For the minority of flies that prove to be annoying on a recurring basis, the primary objective is to deter them rather than kill them. In this case, the remedies are simple:
- use topical repellents containing DEET or Picaridin and wear loose-fitting clothing when outdoors
- install mosquito nets in the house and check them regularly for holes
- keep your food covered, at home and when enjoying warm weather
- empty your trash cans regularly and minimize standing water, both of which can attract unwanted attention.
Avoid catch bug bombs and sprays, which have devastating effects on beneficial insects. If a last chemical resort is necessary, choose selective sprays over broad-spectrum options such as pyrethroids and neonicotinoids, which kill the many good insects along with the few bad ones.
Likewise, it’s best to avoid noisy, electrified, or smelly gadgets that promise a fly-free existence, as most are either ineffectiveor harm far more than their intended targets.
From annoying to essential
Although our daily encounters with a handful of fly species may taint our perception of the group as a whole, such a view is both unwarranted and unwarranted. Flies are among the most diverse animals on the planet and are absolutely essential to the proper functioning of our ecosystems.
Many, like hover, are important pollinators. At a time of declining pollinators and increased food insecuritytheir work in progress is key to supporting agricultural productionand plant life in general.
On the other side of the circle of life are exceptional decomposers, such as the black soldier flies. Each larva can eat twice its body weight per day, which, on the scale of tens of thousands of larvae, represents a promising route to sustainable waste management. They also provide a rich source of protein for livestock, or even humans.
Just as very few flies are harmful, many of them serve as remedies in their biological control role. The approximately 10,000 species of tachinid, or for example, earn their living as parasitoids of other insects. That is, they lay their eggs indoors and eventually kill the developing young of others, which include harmful caterpillars, flies and insects.
As the warm weather arrives, take the opportunity to look a little closer at our agile neighbors and consider their two a stunning diversity and the vital roles they humbly fulfill. The natural world – including us – would not be the same without them.
Thomas White is a lecturer and Tanya Latty is an associate professor, both at the University of Sydney. This piece first appeared on The conversation.