On a sloping hillside yard in the Highland Park neighborhood of Los Angeles, entomologist Lisa Gonzalez kneels to get to work. She's securing the stakes of a 5-foot-tall insect-catching trap made of netting. Homeowner Natalie Brejcha and her daughter, Tenny, look on.
"Insects are basically just randomly flying by," explains Gonzalez. "It's open on two sides. The insects get intercepted by this trap. If you notice, it's darker on the bottom and lighter on the top. Well, if insects are trying to escape, they're going to go towards the light, and toward the apex of the trap. There's a little hole at the top of the bottle, so they fall in and they get collected in the ethanol."
The setup is part of a groundbreaking study being conducted by the Natural History Museum of Los Angeles. It will be one of the most sustained looks at insects in an urban environment ever, and it's happening with the help of 30 property owners across the city. For the next three years, they'll all host traps like these in different parts of the city. The idea, in a nutshell, is to understand the effects of urbanization on living creatures.
"What we're really interested in doing is understand the effect of urbanization on organismal biodiversity," says study manager Dean Pentcheff. "So how is it that we, as we civilized this city — paved it over, diked it, dammed it and channelized it — how have we affected the biodiversity here? The tool we're using to study that is insects. So if you want to study biodiversity, you pick the most biodiverse species on the planet."
Natural History Museum entomologist Lisa Gonzalez adjusting a trap near the L.A. River in the backyard of study participant John Rodriguez.
Indeed, the stats on insects are impressive: Scientists know of roughly 1 million insect species now, but they estimate there are probably closer to 10 million on earth. Every week, each site participating in the study is collecting hundreds of bugs. Most participants found out about the study through the Natural History Museum, and they do have some responsibilities. They're all expected to change the jars once a week and keep an eye on the trap. But to Natalie Brejcha, it’s no problem.
"I know this sounds corny, but we feel really special to get to be a part of this,” Brejcha says. “It's just amazing for our city to get to see what's really here, and I'm just really tickled to be a part of it. So the three-year commitment wasn't that big of a deal to us.”
In Brejcha's kitchen, entomologist Gonzalez pulls out a multicolored specimen to show Tenny.
"This is one of my favorite groups of flies — they're called flower flies, or syrphid flies."
"It kinda looks like a bee," Tenny interjects.
"Yes, I'm glad you brought that up," Gonzalez says. "A lot of flies are mimics of bees and wasps, which means they look just like a bee or like a wasp, but they're not. They're a fly."
For some participants, this experience is the best part of the study — having a personal insect consultant stop by to explain what's really going on in their own backyards. Gonzalez explains to Tenny and her mother that they've collected only three or four flower fly specimens, and the one found in their own backyard was particularly beautiful.
Specimens collected across L.A. as part of the NHM's BioSCAN study.
All of the specimens collected in the study go back to the museum lab to get sorted and archived forever, and will, possibly, yield exciting discoveries pertaining to adaptation. There's a good reason insects can tell us so much about evolution: their short life spans.
"We think of organisms as living through many years," study manager Dean Pentcheff explains, "but for most organisms, a year is much longer than their life span. If you're dealing with something like a small fly, that has a really rapid life cycle, you watch evolution play out."
Since this is one of the longest studies ever to look at insects in an urban environment, researchers all over the world are waiting to get their hands on the data collected in Los Angeles. Geneticists, specialists in bacteria and many others could make new discoveries. New species, cures for disease — with so much unknown in the insect world, anything is possible.