Nature doesn't end at the borders of a city — it's just transformed. That's why scientists are finding new animal species in urban areas, where the ecosystems favour scavengers, hardy weeds, and junk-eaters. It probably comes as no surprise that the sprawling city of Los Angeles is home to its own unique fly species.
Today, members of the BioSCAN group from the Natural History Museum of Los Angeles County described their research on the new fly species in the scientific journal Zootaxa. To find the new species, entomologist Emily Hartop and her team put special insect traps outside 30 different Los Angeles homes, collecting both bugs and data about the weather in the area. For three years, Hartop studied the flies from these traps, eventually looking at about 10,000 different flies. Out of these, she found 30 new species, all in the genus Megaselia (pictured above).
But identifying those species took months, and required minute study of the insects. Hartop wrote on the BioSCAN blog that "90% of our identification work focuses on [genitalia] for flies, we are obsessed with fly genitalia." So basically she spent years looking at fly genitals for science.
Hartop described the progress of her research:
I started to see the same species over and over, I started to notice small differences between the flies when I would sort samples. I started to make little sketches and write notes. Gradually, I started giving these flies funny names: this one's genitalia look like bunny ears, I'll name it "Bunny", this one has setae (socketed hairs or bristles) that remind me of a 1980s troll doll, I'll name it "Troll". I even had a species nicknamed "Hokusai" after the famous painter because its extruded genitalia looked just like details found in The Great Wave off Kanagawa. My colleague, Lisa Gonzalez, contributed by naming one I showed her "Sharkfin" because of its uniquely shaped midfemur. Slowly, the list of "species" I was able to separate grew.
Eventually, she drew pictures of the special genital shapes of all the new species of fly that she found:
Here's the tale of one of the citizen scientists who has a trap in her yard, where one of the new fly species was found. You can get a good look at how the traps work in this video, too.
This project isn't just about the joy of finding cool new species. The majority of the human population lives in cities now, and our science is racing to catch up with what happens to ecosystems and animals that spend most of their lives in cities. What we've discovered from projects like BioSCAN, as well as projects to look at microbes that live in New York subways as well as people's apartments, is that new species are always emerging — and cities are creating their own conditions for natural selection.
Studying urban life is key to our future as a species. It will help us understand how to stay healthy in our metropolises, and hopefully foster urban designs that account for all the life forms that will live beside humans in tomorrow's cities.
As Hartop said in a release about her incredible discovery of 30 new species in just one city:
It means that even in the very areas where we live and work, our biodiversity is critically understudied. It means that in your own backyard, or community park, live species that we do not even know exist. It means that all of those invisible ecosystem processes that occur all around us are being conducted, in part, by creatures we know nothing of.
Read the scientific article at Zootaxa, after April 6.