Every now and then it's a real pleasure to update an earlier story here at KCET, and this is one of those times. Last September we told you, at both Rewild and "SoCal Connected," about BioSCAN, a project by the L.A. County Museum of Natural History to look for new insect species in urban Los Angeles.
The project involved setting insect traps at 30 different locations from the San Fernando Valley through downtown and south to Gardena, then hauling the trapped insects before the educated eyes of NHM entomologists for identification.
As early as September, NHM biologists were confident they'd identified a few new species among the insects caught in the traps. This year has upped the ante: after examining 10,000 individual insects caught in the first three months of 2015, a NHM researcher has identified 30 brand new species of fly -- uncharted biodiversity from urban Los Angeles.
The researcher, NHM entomologist Emily Hartop, focused on phorid flies, a large family of small flies that somewhat resemble fruit flies. Found worldwide, phorids reach their greatest diversity in the tropics. Phorids are sometimes called "coffin flies" because of the dietary preferences of one species in particular, Conicera tibialis, which has been observed feeding on dead people. But many many more phorid species get their animal protein in a way we humans find significantly more palatable: by eating other insects. (To get an idea how some of them do so, consider another common name for certain phorids: "ant-decapitating flies.")Hartop's studies for the BioSCAN project focused on one genus of phorids, Megaselia, which includes about half the world's known phorid species.
In a blog post on the NHM's web site, Hartop describes how she came to work with Megaselia:
After I got a feel for phorids at the family level, I had to learn the Los Angeles species so that I could identify them and we could start tallying them up for our project. [NHM Curator of Entomology Brian Brown]... showed me a species called Megaselia agarici. This species has a prominent, pale protrusion on its genitalia... making it easy to pick out at the species level. Great! With my notebook in hand, I eagerly asked Brian, "So, I can pick out this species, but how do I know this group on the generic level, what is a Megaselia?" Brian's response should have dissuaded me from this group: "Megaselia is a giant genus, about half of the phorid family. Eliminate the other genera as possibilities and if it's not something else, it's likely Megaselia." A sane person would have left it alone. A sane person would have quietly learned the few Megaselia species that are well known and easy to recognize and quietly set the rest aside for someone else to deal with. But not me. I became intrigued.
That interest got complicated. As she examined the thousands of Megaselia specimens that had wandered into the BioSCAN traps, Hartop found a number of individual flies that didn't seem to belong to any of the described North American species. But, as Hartop writes, "To determine if a Megaselia is new to science, you take it through every key for the genus ever written in the world. Megaselia have a way of getting transported across oceans and continents, so you never know when a species that turns up in California might be one originally described elsewhere."
That meant a trip to the U.K. to consult with Cambridge University entomologist emeritus Henry Disney, who has spent his entire career studying Megaselia. The result: Each of the 30 BioSCAN trap sites turned out to have collected a Megaselia species previously unknown to science.
In a paper to be published next week in the journal Zootaxa, Hartop and her colleagues name each of the species after the human residents of the properties on which the BioScan project's traps collected that species, which is a nice thing to keep in mind should you ever consider taking part in a similar citizen science project.
Not bad for a project that started out when the NHM's Brian Brown bet a colleague he could find a new species of insect in a particular Los Angeles backyard. Brown set a trap in that backyard; the first insect trapped turned out to be a new species. That was the inspiration for the BioSCAN project, which has now made a startling contribution to our knowledge of Los Angeles' biological diversity.
"I always thought we had the potential to discover new species wherever we sample--urban, tropical, anywhere," Brown told Phys.org. "But 30 new species from a heavily urbanized area is really astounding."
"Right now we're finding out what's here, and it's more than we ever expected," added Hartop. "By linking these biodiversity results with the physical data we're collecting at these sites, we'll be able to contribute directly to the policy discussion of how best to plan and manage urban biodiversity."
This video by The Next Gen Scientist goes into more detail on BioSCAN and Hartop's work.
It's all a great reminder that much of the living world we see in the course of a typical day might be as-yet undescribed by science -- even at a backyard barbecue in Glassell Park.