Falling in Love with a Fly

It’s one thing to fall in love with creatures we consider regal, clever, or sweet, but what about those we’ve learned to swat away? I’ve never liked flies, especially after an encounter years earlier on the great Gariep River, which stretches from South Africa into Namibia. At the time I had begun experimenting with creating land art, which I’d felt drawn to after seeing the work of Andy Goldsworthy. I struggled greatly at first before managing to find my own simple style—placing natural objects like bones, stones, shells, and kelp in patterns on the ground and then photographing them in the landscape.

Not long after I’d arrived in the area, millions of tiny flies that had recently reproduced were congregating in giant swarms. Most of the other people fled the area until the swarms passed, but I was committed to venturing out, desperate to do my art. I was bitten everywhere, and no amount of waving a branch over my head helped.

Eventually I tied a mosquito net over my head. Still, it was very hard to tolerate the swarms, which sometimes dimmed the sun. The only positive was that I had the entire wild landscape to myself.

And so I couldn’t imagine loving a fly. But that all changed when I got a glimpse inside their lives. It first started when Jannes Landschoff, my marine biologist friend and colleague, and I were out one afternoon and I noticed strange little tracks on bare granite rock in the upper intertidal zone of the ocean, the area that gets wet at high tide only. I asked Jannes about these tracks, which looked like little white squiggles, and he thought they might be traces of salt left in the cracks. We kept walking, and then I saw them again.

By that point, I’d been focused heavily on tracking and my eyes were keyed to pattern recognition. Something told me these weren’t random salt traces. Jannes and I got down on our hands and knees and looked up close.

The larva turns into a liquid, and somehow that liquid knows how to make a creature that can fly.

There we found strange little leathery casings that had attracted tiny particles of sand. Suddenly Jannes gasped. “Oh my God,” he said. “It’s larvae.”

Totally hidden on what looked like rock around us were hundreds of animals. We had no idea what they were because they were still in larval stage.

“A beetle, maybe?” Jannes wondered.

I had no idea. We sent the pictures to University of Cape Town professor Charles Griffiths, who had become my trusted mentor in all things marine biology. He thought it was the larvae of a marine fly.

“Marine insects are rather rare,” he added. “Please try to find the creature that hatches once the larvae transform, as it could be new to science!”

This is what I love about tracking: I get to become a nature detective.

So every day I kept returning to the same spot. With my friend and collaborator Pippa Ehrlich’s help, I found empty casings where the animal had hatched—and she found one rather strange looking fly still attached to its cocoon with its wings all curled and folded up.

I waited for movement, but there was none that day. I did discover many of the larvae were actually underwater in shallow pools—this truly was a marine insect.

It was when I began to do further research on this humble fly’s life cycle that I discovered something fascinating. The flies lay eggs, which then hatch into larvae. These larvae are eating machines, the great composters of nature, turning dead matter into nutrients. But the really interesting part is when the creature has reached the end of its larval cycle but before it becomes an adult fly. I’ve always thought the larva somehow grows wings and legs and transforms that way, but what happens is very different.

The larva first turns into a liquid, and somehow that liquid knows how to make a creature that can defy gravity and fly. Out of the liquid, the atoms rearrange themselves to produce a perfect little flying machine.

If you gave a bunch of our best scientists a billion dollars they’d be hard-pressed to make a fly from scratch.

Nature is priceless.

A week later Jannes and I set out to find our mystery fly. It was midwinter, the wind was freezing, and I was not confident about our chances. We searched everywhere, and just as we were about to give up, in the last pool we found one perfect fly resting on kelp. I had a few seconds to set my camera to macro and take a few images before the wind blew the fly away.

How does an animal made of material softer than paper survive and thrive in a place that is so hostile to something so small—where huge waves thrash against rocks, temperatures fluctuate wildly, and predators abound?

After just a week of tracking that long-legged silvery fly, I glimpsed its magnificence and its magic.

I’d thought it impossible, but I’d fallen in love with a fly.

Lead photo by Craig Foster

Craig Foster

Posted on May 16, 2024

Craig Foster is a documentary filmmaker and founder of the Sea Change Project, a nonprofit environmental storytelling organization. His My Octopus Teacher won the Academy Award for Best Documentary Feature in 2021.