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This Wild Life: Creating California’s First Insect Library

It’s June. It’s 70 degrees and sunny. In a small montane meadow in Cuyamaca Rancho State Park, every color of wildflower peers up through lush grasses. There are butterflies and bees, flies and beetles foraging and riding the breezes. Eva Horna-Lowell and Ellie Deertwo early-career entomologists from The Nat—take it all in for a moment, then swish-swish single-file across the clearing. 

Eva leads the way toward two tent-like contraptions at the far edge of the meadow. “Ohhh wow!” she shouts, gripping the clear plastic bottle hanging at the top of the nearest tent. “There are probably five or six thousand specimens in here.”  

The tents are malaise traps, and they’ve been catching bugs for exactly one week. With mesh walls stretched between a PVC scaffold, the traps intercept flying insects, funneling them upward toward a bottle filled with preserving liquid.  

The traps in this serene spot make up a “snapshot” site: one of nearly 100 randomly selected locations across Southern California where Eva is sampling insect diversity for just one week. This work is part of the California Insect Barcode Initiative (CIBI), a state-funded project aimed at documenting all the insect life throughout California as part of Governor Newsom’s 30x30 executive order to conserve 30% of California’s land and waters by 2030. The Nat is in charge of documenting San Diego and Imperial Counties, with Eva at the helm. She caps the bug-filled bottles and helps Ellie break down the traps. 

“In the insect world, we're still in the discovery stage that other biologists found themselves in a century ago,” explains Eva, referring to the sheer biodiversity she and her peers work with as entomologists. “We still need to document which insects even exist here.” 

These insects from a blue-vane trap will be sorted, identified, and DNA barcoded.

Back in the Museum, the entomology team and their volunteers will use microscopes to sort these thousands of insects into their respective Orders, like the flies (Diptera), the beetles (Coleoptera), and the moths and butterflies (Lepidoptera). Some specimens will be sent off to the University of Guelph in Ontario, Canada for photographing and DNA sequencing; others will be added to the Museum’s collection.  

“It is a lot of time and effort, says Eva, “But I am always excited to see what we’ve caught when I’m back in the lab.” 

Using new specimens from the field and old specimens from museum collections, CIBI’s participating scientists are creating the most comprehensive library of California insect DNA to date. This project trails behind a growing public awareness of the “insect apocalypse,” the name given to the estimated 70% loss of insect diversity and biomass around the planet since the 1970s.  

The hope is that land managers, scientists, students, and other professionals will use this DNA library to inform statewide insect conservation and management practices in the face of continued insect loss. When someone samples California’s insects in the future (as part of an agricultural project, for example), they’ll be able to use this DNA reference library to figure out which insects are in the area. Instead of relying on trained entomologists to identify everything one-by-one, they can run large batches of specimens through a DNA sequencer, compare results with the library, and be on their merry way—no experts necessary 

“This makes insect conservation more accessible to anyone who wants to understand and protect the bugs in a park, an ecosystem, or a larger region,” says Eva. “It will give all of us so much more knowledge about our native species, and we’ll be able to pass that on to the public with official species lists and field guides.”  

Eva (left) and her field assistant Ellie check pitfall traps at one of their survey sites in east county.

Team Work Makes the Field Work Dream Work  

As Eva makes her way further down the meadow, her excitement is palpable as she approaches two fluorescent plastic containers hanging from metal hooks.  

“This is a blue-vane trap—they’re my favorite traps ever,” she shares. “They specifically target bees and wasps because the color combination of bright blue and yellow attracts them, like a flower.”  

The yellow tubs are full of insect soupmaybe 1,000 specimens in each. Eva confesses her bias for bees, the subject of her college and graduate studies. “Running up to the blue-vanes to see what we caught is like Christmas for me, every time.”  

Eva and Ellie wrap up the PVC malaise trap poles, dig stakes from the ground, and stuff everything into their backpacks. They make quick work of it—these two are a well-oiled machine 

For Ellie, who graduated from Point Loma Nazarene University in 2022, working in an all-women lab is comfortable, yet encouraging. Eva is a lot further in her career than I am, but we still have a lot in common,” she says. We have great conversations, we love listening to podcasts on long drives or having a beer after a long day, but her guidance and knowledge still come through.  

For Eva, it’s all part of the job. “I want others to feel as good as I do when I get to work outside. Had somebody not done that for me when I was a junior in college, I wouldn’t have known that fieldwork was an option. I’m just paying it forward. 

Eva is the lead entomologist in charge of San Diego and Imperial Counties for the CIBI project.

The ladies pack up the truck and drive 45 minutes to a completely different ecosystem: the desert-chaparral transition zone. The next site is the same set-up, but this locationon private property near Tierra Del Sol—is a long-term “observatory” site, meaning Eva collects insects here for one week each month for the 15-month- long project 

"We got a cicada!" shouts Ellie, holding a blue-vane trap to her face. "OooOOoo!" Eva shouts back, her face buried in the other trap. “We got a big ‘ol bumble bee in this one.” 

Both women are grateful for any specimens at this site. Winter and spring storms have flipped, flung, and downright destroyed their traps on several occasions. “We didn’t even set out traps in January because the rains

 were so crazy, says Eva. “I’m on way more than I thought I would be, and I’ve had to rethink my methods each month for about 3-4 months to deal with weather challenges. But this iterative process is what makes science fun for me,” she laughs, “I get to be like MacGyver. 

On the truck’s tailgate, Eva and Ellie carefully pour, filter, rinse, and re-pour the specimens into labelled jars. Tomorrow, they’ll do the same for an observatory site in Picacho State Park and two more snapshot sites in Imperial County, and then head to Borrego Springs to sample nocturnal insects with blacklight traps. The next day they'll visit three more observatory sites in north San Diego County.  

They will repeat a similar circuit two weeks later to reopen the observatory traps and set two more snapshot locations. Every other scientist on the CIBI project will do the same thing, at the same time, for hundreds of sites across the state. The broadness of this project, coupled with the high frequency of sampling, will prove invaluable to entomologists and the greater conservation community 

“We’re going to have a whole year of data, so we’ll see if some species are declining, we might detect non-native pests, and we’ll for sure discover new species,” says Eva. “This is our state’s first massive inventorythere’s about a million things we could find out. 

California is one of the most biodiverse places in the world. Once we know how many insect species live here, we’ll be that much closer to maintaining our speciose status long into the future.  

Read more:

Residents Become Canyon Stewards

The This Wild Life series showcases ongoing fieldwork at The Nat and the people behind it. Join our researchers and partners as they slog through frog ponds, dig up fossils, and track down lost speciesmaking conservation possible with each data point and discovery. From southern California to the tip of the Baja California Peninsula, our scientists are quite literally the boots on the ground, working to preserve this amazing place we call home.  

Eva and Ellie check malaise traps near Tierra del Sol in San Diego County.

The diversity of insects in California is extremely high, but we still have much to learn about which ones even live here.

Weather is a constant challenge with fieldwork. Eva has had to repair many broken traps due to heavy wind and rain.

Posted by Cypress Hansen, Science Communications Manager on July 28, 2023

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