It’s a beautiful summer day, you’re outside, ready to enjoy a BBQ. The smell of grilling food is in the air, and relaxation is on the agenda. You settle into your chair, cold drink in hand, and then you hear it – that unmistakable buzzing sound. Flies. Suddenly, your peaceful afternoon is under siege. You swat, you wave, but they persist, those seemingly tireless, tiny tormentors.
Yes, flies can be incredibly annoying. But before you reach for the swatter again, consider this: flies often get a bad reputation they don’t entirely deserve. In fact, they might just be the unsung heroes of the ecosystem, especially during those warm summer months.
Why the Summer Swarm? The Science Behind Fly Activity
It might feel personal when flies seem to descend upon us in droves during summer, but their increased presence isn’t about targeting humans for annoyance. It’s driven by a fascinating interplay of environmental factors, primarily winter rainfall, food availability, and, crucially, temperature.
Insects, including flies, are ectothermic, often called “cold-blooded.” This means their body temperature is directly influenced by their surroundings. As summer temperatures rise, so does their metabolic activity. Warmer weather speeds up their life cycle, from hatching to adulthood, leading to a population boom.
Many fly species spend the colder months in a dormant phase, often as larvae or pupae. Spring and summer signal their emergence as winged adults, ready to feed and reproduce. These adult flies, often young and driven by biological imperatives, are the ones we encounter most frequently in summer. Think of it as an insect version of spring break, but lasting for months!
Check out this blog post for more info on why summer is the hot month for insects.
So, now we understand why they’re around more in summer, the real question becomes: “What do flies actually do?” And the answer might surprise you.
Pollination Powerhouses: Flies as Unsung Floral Allies
Think about your last summer BBQ. Most of the delicious food you enjoyed likely exists thanks to the hard work of pollinators. Bees and butterflies usually get all the credit, but flies are actually incredibly effective pollinators, often working just as well, if not better, than honeybees in many cases.
Honeybees, while excellent pollinators, have specialized pollen baskets on their legs. These baskets are great for collecting pollen to bring back to the hive, but they make the pollen less available for actually pollinating the next flower they visit. Flies, on the other hand, lack these baskets. Pollen readily sticks to their hairy bodies and is easily transferred from flower to flower.
“Horseflies are fantastic pollinators because they’re so hairy,” explains Dr. Bryan Lessard, an entomologist at the Australian National Insect Collection, known as “Bry the Fly Guy.”
“Recent research from the University of New England demonstrates that common blow flies can carry more pollen on their bodies than honeybees,” he adds.
While female horseflies are known for occasionally needing a blood meal to get protein for egg development, their primary food source is nectar from flowers. The exact range of plants they pollinate is still being researched, but their role is significant.
And it’s not just fruits and vegetables. Flies are also vital for pollinating hops used in beer, apples for cider, and grapes for wine. So, next time you raise a glass, remember to give a tiny thanks to the flies!
Image: Plinthina beyonceae fly, named after Beyoncé, showcases the surprising beauty found in some fly species.
Flies as Food: A Crucial Link in the Food Chain
While you might find flies bothersome, they are a vital food source for many animals that we appreciate. Birds, lizards, frogs, and even some mammals rely on flies as a protein-rich meal. Flies are a critical link in the food web, supporting a diverse range of wildlife.
Beyond just being food for wild animals, flies are also emerging as a potential food source for farmed animals. As the global population grows, finding sustainable and efficient sources of animal feed is becoming increasingly important. Enter the black soldier fly.
Researchers have discovered that black soldier fly larvae meal can serve as a partial or complete replacement for traditional agricultural feed in livestock diets. Studies have shown that this insect-based feed is suitable for chickens, pigs, alligators, and farmed seafood like blue tilapia, Atlantic salmon, and prawns, without any negative impacts on animal health. So, flies could indirectly be helping to feed a growing human population!
Read more about feeding our growing population with flies.
Nature’s Clean-Up Crew: Flies and Waste Management
Flies have a less glamorous, but equally essential role: waste management. They are nature’s recyclers, helping to break down and dispose of organic waste, including, yes, poo.
Flies, particularly larvae like maggots, consume decaying organic matter, preventing it from accumulating and becoming a health hazard. Black soldier fly larvae, for example, are voracious eaters. A single female can lay up to 600 eggs, and each larva can consume half a gram of organic waste per day. A small colony of these flies can process a significant amount of household green waste annually, diverting it from landfills.
Flies act as scavengers, consuming rotting carcasses and other organic debris. This process is vital for nutrient cycling and preventing the build-up of unpleasant waste in our environment. Imagine a world without flies to break down organic matter – it would be a much less pleasant place. They essentially turn waste into valuable resources, like insect biomass that can then feed other animals.
Medical Maggots: Healing with Fly Larvae
Speaking of maggots, their role extends beyond just waste disposal. In a surprising twist, maggots have been used for centuries in medicine, particularly for treating infected wounds. The first documented use of maggots for wound cleaning dates back to soldiers in the American Civil War.
Certain types of fly larvae, like sheep blowfly larvae, are used in a treatment called maggot debridement therapy (MDT). These maggots are applied to wounds, such as diabetic ulcers and bedsores, where they selectively consume dead and infected tissue. They cleanse the wound with their antibacterial saliva and stimulate the growth of new, healthy tissue, promoting faster healing. This can be particularly beneficial in cases where antibiotic resistance is a concern.
It’s important to note that medical maggot therapy is a controlled medical procedure. “Maggot nurses” supervise the treatment, monitoring the larvae’s progress. Once they have done their job, the maggots are simply removed.
Find out more about maggots and other animals that have medical uses.
Beauty in the Buzz: Appreciating Fly Diversity
Beyond their ecological roles, flies themselves can be surprisingly beautiful and diverse creatures. Consider the Lecomyia notha soldier fly from Queensland, Australia. Its exoskeleton shimmers with iridescent purple hues, resembling a miniature, living opal galaxy.
Entomologists are continually discovering new fly species, highlighting the vast biodiversity within this insect group. Dr. Bry the Fly Guy, while working in the Australian National Insect Collection, identified a new species with a striking golden abdomen. He named it Plinthina beyonceae, in honor of the pop icon Beyoncé, recognizing its dazzling beauty.
So, while flies may test our patience when we’re trying to relax outdoors, they are far more than just annoying pests. They are crucial pollinators, waste managers, a vital food source, and even have medical applications. Next time you’re tempted to swat a fly, remember the many essential roles they play in the ecosystem. Australia’s incredible biodiversity, including its fly species, is a treasure worth appreciating and conserving.
