A new study published in the journal Ecography finds that there are more than 60,000 different species of insects in California—and scientists have only described about two-thirds of them. Led by researchers at the Natural History Museum of Los Angeles County, the study marks a figurative explosion in the number of insect species in the Golden State. The vast gulf between the earlier and new estimates of insect life deepens the urgency of conserving the wild places these insects call home. The authors found that essentially every site studied had its own unique insect communities from one another.
This finding comes from the unprecedented work of the California Insect Barcode Initiative (CIBI), a six-million-dollar grant-funded project to collect and identify every species of insect in the state. Despite being the most diverse group of animals on land, researchers have long known they are underrepresented in large-scale conservation assessments. To address this deficit, institutions including the California Department of Food and Agriculture, UC Berkeley, UC Riverside, San Diego Natural History Museum, and the California Academy of Sciences in San Francisco worked alongside NHM researchers to DNA barcode more than one million insect specimens, and this finding marks the first publication from this massive undertaking.
Ecoregions
To build the library, researchers collected tissue samples from museum collections like NHM's. They also set Malaise traps in 72 ecoregions statewide and undertook dedicated expeditions to 454 additional locations across California. Malaise traps passively capture insects, but their maintenance requires active labor.
"This is an example of community science. Volunteers stepped forward to help with sampling by managing traps, which we would not have been able to do for continuous weekly sampling," says co-author and NHM Entomology collections manager Giar-Ann Kung. Along with Baker, researchers from all over the state, and an army of volunteers, Kung set Malaise traps and collected throughout the state to capture insects. "There are people like Sara Fairchild and Michael Nance who managed a Malaise trap for over three years at a site in the high desert, which is the longest continuous site for the project. That could not have been accomplished without them."
Ecoregions are places with similar ecosystems defined by the Environmental Protection Agency, which further subdivides them into different levels. The study looked at Level 3 ecoregions which include designations like Mojave Basin and Range, Southern California Mountains, and Sierra Nevada. The authors found that the Mojave Basin and Range had the highest insect species richness.
They also compared parallel ecoregions and found that each one had a unique tapestry of insect life, even if it shared a climate and geography. "The deserts are kind of more similar to each other, and the mountains in northern California are a little bit more similar to each other, but every part of the state hosts a really different insect fauna," says Dr. Barkdull.
While there are parallels between locations that fall within the same ecoregion, the diversity at each was unparalleled. The richness of life across the state is both more abundant and more delicate than previously thought, highlighting the need for more aggressive conservation of California's wild places.
