The federally endangered Delhi Sands flower-loving fly can only be found in the Colton Dunes of the Inland Empire, but their behavior and legal protections make them a rare sight.

Most of the year Delhi Sands flower-loving flies live below the surface in their larval state, burrowing through the sand eating other insect larvae. In the summer they emerge, immediately seeking a mate to continue the next generation. Their flight season lasts from June to September, and they are most active between 10:00 am and 2:00 pm, but that does not mean they are easy to find.

Even though most of us have never seen the reclusive insect, our staff and volunteers spend a tremendous amount of time and energy removing invasive plant species, collecting native plant seeds, and planting native shrubs to revitalize the habitat that is required for the flower-loving fly to thrive.  Plots of land that were fields of invasive grasses five years ago are now dominated by native species today. Planning and executing the restoration of this habitat is fulfilling, but I’ve often wondered if I would ever get to see the species we spend so much time protecting.

Rivers & Lands Conservancy has leaned on the expertise of permitted entomologist and long-time friend, Ken Osborne, to perform surveys on our preserves in Colton, Rialto, Fontana, and Ontario. Last year I started the process of obtaining a survey permit from U.S. Fish & Wildlife Service for the Delhi Sands flower-loving fly. This summer Osborne supervised me to obtain the twenty hours of required field experience with the species. Surely under his expert guidance I would spot the elusive fly.

We started our survey at the West Valley Habitat Conservation Plan Preserve one August morning just after 9am when the temperature was still mild. As we searched, Osborne caught and quizzed me on the identity of various insects I will have to know for the permit’s required insect identification exam. I was doing well for someone without an entomology degree but was still anxious to see the star of this survey. After about twenty minutes of wandering, Osborne yelped in muted excitement, “Got one!”

He threw his clipboard to the ground hastily and whipped out a DSLR camera with an impressive lens. He whispered, “No sudden movement!” and motioned me to be still as he snapped photos. I complied, but we were both tamping down our rising excitement. At long last, I was getting a close look at the species Rivers & Lands Conservancy was working so hard to protect.

As the day got warmer, Osborne explained how the fly’s behavior would change. We were no longer looking for flies sunbathing on the bare sand, but instead they would be cruising around shrub clusters searching for a mate and unwilling to stop.

Once you’ve spotted your first flower-loving fly, their flight pattern is unmistakable. They loop through the air in a pattern reminiscent of their own air-drawn cursive signature. They advertised their availability to mates with these graceful missives and we followed them hoping futility to shoot clear photographic evidence. We wanted to document not just proof of life, but also the success of so much hard work. As temperatures started to peak in the early afternoon, even Osborne had to admit that the survey day was over.  The flies like it hot, but even they know their limits.

I was still buzzing from my first glimpse of the secretive insect, but I was also aware that we have a long way to go for the species to recover. Osborne shared sobering tales of seeing them by the dozens back in the eighties in some areas. We had been thrilled to just see a few, but we won’t let the stark contrast squash our optimism.

We will continue working to conserve and restore the sand dune habitats aiming to bring the populations back to their former abundance and we welcome the community to join us. Our volunteers who help with sand dune restoration in the months before and after flight season may never chance upon a flower-loving fly. They do, however, witness the other flora and fauna that benefit from these efforts and enjoy the satisfaction, friendship, and community that come with volunteering! Save the fly and you save the dunes.

Rivers & Lands Conservancy connects our community to natural, wild, and open spaces of Southern California through land conservation, stewardship, and education.

Michael Viramontes is the stewardship manager of Rivers & Lands Conservancy, has a bachelor’s degree in environmental studies and natural resource management from San Jose State University.