California is home to more than 60,000 insect species, and scientists have formally described only about two-thirds of them, according to a study published Nov. 4 in the journal Ecography. The finding comes from the first publication of the California Insect Barcode Initiative, which DNA barcoded more than 1 million insect specimens collected across the state.

The result is striking — California has some of the most intensively studied landscapes in the country, with major universities, museums and agricultural research programs. Earlier estimates placed California's insect diversity anywhere from about 26,000 to 100,000 species, a range so wide it showed how little was known.

That gap matters beyond science. A species that has never been named cannot be assessed for extinction risk, placed on a protected list, or factored into land-use decisions, which means much of California's wildlife is effectively invisible to conservation planning.

A Million Specimens and a Genetic Shortcut

The project, led by the Natural History Museum of Los Angeles County, is a $6 million grant-funded effort to collect and identify every insect species in California. Partners include the California Department of Food and Agriculture, UC Berkeley, UC Riverside, the San Diego Natural History Museum and the California Academy of Sciences, according to the museum's release.

Researchers set Malaise traps, tent-like nets that funnel flying insects into collecting bottles, in 72 ecoregions and made dedicated trips to 454 additional sites. Volunteers managed many of those traps. "This is an example of community science," said Giar-Ann Kung, the museum's entomology collections manager.

DNA barcoding reads a short, standardized gene fragment to sort specimens into likely species far faster than examining each under a microscope. A preliminary completeness analysis suggests the more than 60,000 species identified represent about 65% to 69% of the state's true insect fauna, Gizmodo reported. That means the real total is likely well above 60,000.

Some of the work required patience as much as technology. Volunteers Sara Fairchild and Michael Nance kept a high-desert Malaise trap running for more than three years, the project's longest continuous site. "No matter how you slice and dice it, there are a tremendous number of insect species in California," Barkdull said, adding that the team is "not anywhere close to having collected them all."

"We've been all over the state using every collecting method in the book, and our efforts have resulted in one of the largest insect biodiversity datasets ever put together," said lead author Austin Baker, a senior research scientist at BioKEA and former museum postdoctoral fellow, according to MyNewsLA.

The Mojave Desert Surprise

The richest insect communities did not turn up where many people would expect — in lush forests or wetlands. Among the broad ecoregions studied, the Mojave Basin and Range had the highest insect species richness, according to the museum. Gizmodo noted that the Southern California Mountains also ranked among the highest in estimated richness.

"It was surprising to learn that the Mojave Desert is one of the most species-rich areas that we sampled," Baker told Mongabay. Deserts look barren to visitors, but spring wildflower blooms, varied soils, isolated mountain ranges and specialized plant-insect relationships can support remarkable diversity.

Just as notable, nearly every site held its own distinct community, even when climates and landscapes looked similar. "I didn't expect that every single ecoregion would be home to a starkly different insect fauna," said co-author Megan Barkdull, assistant curator of entomology at the museum.

Conservation Maps May Be Missing a Hidden Majority

That pattern challenges a common shortcut in conservation. Many planning tools, including California's Areas of Conservation Emphasis maps maintained by the state wildlife department, rely heavily on data from plants and vertebrates such as birds, mammals and reptiles. The assumption is that protecting places rich in those groups protects everything else too.

The new data suggest that assumption does not hold well for insects. "We can't use them as proxies when making decisions that aim to conserve this critical portion of our biota," Barkdull said. The museum's release called for more aggressive conservation of California's wild places.

Insects make up roughly 80% of the planet's animal species, with about 900,000 described worldwide, Popular Science noted. California's share of that diversity sits on top of intense pressure from urban growth, wildfire, drought and invasive species.

The stakes connect to daily life. Insects pollinate many of California's crops, recycle nutrients, feed birds and fish, and include both agricultural pests and their natural enemies. Studies point to insect declines worldwide, but many regions lack the baseline data to measure them, and this dataset can serve as that baseline for California.

Barcodes Are a Start, Not a Name

The study is peer-reviewed, but its species count rests on genetic groupings, and its completeness figure is a preliminary estimate. "DNA barcoding is an excellent way to discover and delimit species, although it is not perfect," Baker has said, noting that checking accuracy requires going back to the preserved specimens.

Formal naming is slower still. Each new species needs a detailed description by a taxonomist, and there are far fewer specialists than undescribed insects. The barcodes and specimens, now available through the public Barcode of Life Data System, give those experts a starting map.

Readers can contribute directly. Community science platforms and museum volunteer programs routinely need help with trap monitoring and photo records, and gardeners can support local insect diversity by planting native species and limiting broad-spectrum pesticides. Future CIBI publications are expected to analyze specific regions and insect groups in more detail.

What Readers Want to Know

How many insect species live in California? More than 60,000, according to the California Insect Barcode Initiative's first study, published Nov. 4 in Ecography.

How many are unnamed? About a third. Scientists have formally described only about two-thirds of the species identified.

Where are insects most diverse in California? The Mojave Basin and Range had the highest species richness among broad ecoregions studied, with the Southern California Mountains also ranking high.

How did researchers count them? They DNA-barcoded more than 1 million specimens from traps in 72 ecoregions and 454 additional sites.

Why does this matter for conservation? Planning maps based on plants and vertebrates may miss insect hotspots, since insect communities differ sharply from place to place.

Can the public help? Yes. Volunteers helped manage traps, and gardeners can support insects by planting natives and reducing pesticide use.