DNA barcoding of more than one million insect specimens indicates that at least one third of California's insect biodiversity remains undiscovered

DNA barcoding of more than one million insect specimens indicates that at least one third of California's insect biodiversity remains undiscovered | Authorea try { document.documentElement.classList.add('js'); } catch (e) { } var _gaq = _gaq || []; _gaq.push(['_setAccount', 'G-8VDV14Y67G']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); Skip to main content Preprints Collections Wiley Open Research IET Open Research Ecological Society of Japan All Collections About About Authorea FAQs Contact Us Quick Search anywhere Search for preprint articles, keywords, etc. Search Search ADVANCED SEARCH SCROLL This is a preprint and has not been peer reviewed. Data may be preliminary. 5 December 2025 V1 Latest version Share on DNA barcoding of more than one million insect specimens indicates that at least one third of California's insect biodiversity remains undiscovered Authors : Austin Baker 0000-0002-4728-726X , Brad Balukjian , Hilary Bayer , Jen Bayer , Daniel Gluesenkamp , Christopher Grinter , John Heraty , … Show All … , Amanda Hodson , Eva Horna Lowell , Colleen Kamoroff , Severyn Korneyev , Giar-Ann Kung 0000-0002-8099-6949 , Peter Oboyski , Leslie Saul-Gershenz , Jayme Sones , Rebecca Stiling , Christiane Weirauch , Shayda Abidi , Elliott Allen , Rachel Allingham , Edeline Anthoniraj , John Ascher , Kelsey Bares , Julia Betz , J. Blair , Christina Buck , Franklyn Cala-Riquelme , Stephanie Castillo , Ellie Deer , Shahan Derkarabetian , Natalia von Ellenrieder , Lauren Esposito , Sara Fairchild , Glenn Fine , Brian Fisher 0000-0002-4653-3270 , Glen Forister , Lorenzo Fraysse 0000-0002-8680-7803 , Juan Grados , Laura Gaudette , Michael Gengo , Jacob Gorneau , Scott Hardage , Paul Hebert , Elizabeth Hiroyasu , Pam Horsley 0000-0003-3362-2255 , Camille Hymes , Jacob Jones , Kevin Keegan , Peter Kerr , Emma Kurstjens , Jesse Laine , Bethany Leach , Socrates Letana , Valerie Levesque-Beaudin , Benjamin Maples , Martin Melia , Joe Miller , Christiana Mojica , Spencer Monckton , Denise Montelongo , Michael Nance , Michael Nee , Sarah Nguyen , Avas Pakrashi , Mikko Pentinsaari 0000-0001-7241-3873 , Julia Perez , Diana Phan , S Pike , Kipp Pow , Nomena Rasoarimalala 0009-0004-1498-1388 , Sujeevan Ratnasingham , Sylvia Reyes , Samantha Richey , Orlando Romeo 0000-0002-4559-2199 , Cristina Sandoval , Ken Schneider , Michael Schweiker , Katja Seltmann 0000-0001-5354-6048 , Stevie Steele , Nathan Tang , Lauren Tham , Wilfred Valtakis III , Matthew Van Dam , Elise Vasquez , Vanessa Verdecia , David Wagner , Michael Wall , P. Signe White , Jakob Woodall , Yanega Doug , Evgeny Zakharov , Megan Barkdull , Brian Brown , and Laura Melissa Guzman [email protected] Show Fewer Authors Info & Affiliations https://doi.org/10.22541/au.176494887.72780666/v1 996 views 383 downloads Contents Abstract Supplementary Material Information & Authors Metrics & Citations View Options References Figures Tables Media Share Abstract Insects are the most diverse terrestrial organisms, yet they are underrepresented in large-scale conservation assessments. To address this gap, the California Insect Barcoding Initiative is developing a publicly accessible, statewide DNA-barcode reference library for California insects to support scalable surveys, establish baseline biodiversity measurements, and generate potential distribution maps that inform conservation planning. Specimens are collected with a hybrid strategy that combines standardized Malaise trapping, to enable replicable sampling, and opportunistic collecting, to maximize taxonomic coverage. To date, we have barcoded over one million specimens; preliminary completeness analyses suggest that current sampling captures roughly 65–69% of the fauna, implying a conservative minimum of circa 61,000 insect species in California. Using all sequenced specimen records, we generated rule-based spatial range interpolations constrained by ecoregion and vegetation type, and used these to infer spatial patterns in insect species richness across the state. We identify areas of both high and low potential species richness, with current peaks in the Southern California Mountains ecoregion and the Mojave Basin and Range ecoregion. Our species richness estimates and spatial patterns are explicitly provisional and are expected to evolve as sampling gaps are addressed. Finally, we make all sequence data, specimen images, and occurrence records publicly available via the Barcode of Life Datasystem. This ongoing effort constitutes the first large-scale DNA barcode-based survey for California insects, providing an expandable foundation for tracking temporal change, testing drivers of insect diversity, and prioritizing regions for conservation and targeted inventory. Supplementary Material File (main_text.pdf) Download 2.30 MB Information & Authors Information Version history V1 Version 1 05 December 2025 Copyright This work is licensed under a Non Exclusive No Reuse License. Keywords biodiversity california dna barcoding insecta Authors Affiliations Austin Baker 0000-0002-4728-726X Natural History Museum of Los Angeles County View all articles by this author Brad Balukjian California Academy of Sciences View all articles by this author Hilary Bayer Silicon Valley Barcode of Life View all articles by this author Jen Bayer Silicon Valley Barcode of Life View all articles by this author Daniel Gluesenkamp California Institute for Biodiversity View all articles by this author Christopher Grinter California Academy of Sciences View all articles by this author John Heraty University of California Riverside View all articles by this author Amanda Hodson University of California Davis View all articles by this author Eva Horna Lowell San Diego Natural History Museum View all articles by this author Colleen Kamoroff Stillwater Sciences View all articles by this author Severyn Korneyev California Department of Food and Agriculture Plant Pest Diagnostics Center View all articles by this author Giar-Ann Kung 0000-0002-8099-6949 Natural History Museum of Los Angeles County View all articles by this author Peter Oboyski Essig Museum of Entomology View all articles by this author Leslie Saul-Gershenz University of California Davis View all articles by this author Jayme Sones University of Guelph Centre for Biodiversity Genomics View all articles by this author Rebecca Stiling Nature Collective View all articles by this author Christiane Weirauch University of California Riverside View all articles by this author Shayda Abidi Stillwater Sciences View all articles by this author Elliott Allen Stillwater Sciences View all articles by this author Rachel Allingham San Diego Natural History Museum View all articles by this author Edeline Anthoniraj North Carolina State University at Raleigh View all articles by this author John Ascher National University of Singapore View all articles by this author Kelsey Bares SUNY College of Environmental Science and Forestry View all articles by this author Julia Betz California Academy of Sciences View all articles by this author J. Blair San Francisco State University View all articles by this author Christina Buck Stillwater Sciences View all articles by this author Franklyn Cala-Riquelme California Academy of Sciences View all articles by this author Stephanie Castillo Natural History Museum of Los Angeles County View all articles by this author Ellie Deer San Diego Natural History Museum View all articles by this author Shahan Derkarabetian San Diego Natural History Museum View all articles by this author Natalia von Ellenrieder California Department of Food and Agriculture Plant Pest Diagnostics Center View all articles by this author Lauren Esposito California Academy of Sciences View all articles by this author Sara Fairchild Natural History Museum of Los Angeles County View all articles by this author Glenn Fine California Academy of Sciences View all articles by this author Brian Fisher 0000-0002-4653-3270 California Academy of Sciences Entomology Department View all articles by this author Glen Forister University of California Davis View all articles by this author Lorenzo Fraysse 0000-0002-8680-7803 California Academy of Sciences View all articles by this author Juan Grados Universidad Nacional Mayor de San Marcos Museo de Historia Natural View all articles by this author Laura Gaudette McGuire Center for Lepidoptera and Biodiversity View all articles by this author Michael Gengo Stillwater Sciences View all articles by this author Jacob Gorneau California Academy of Sciences View all articles by this author Scott Hardage The Nature Conservancy in California View all articles by this author Paul Hebert University of Guelph Centre for Biodiversity Genomics View all articles by this author Elizabeth Hiroyasu The Nature Conservancy in California View all articles by this author Pam Horsley 0000-0003-3362-2255 San Diego Natural History Museum View all articles by this author Camille Hymes Stillwater Sciences View all articles by this author Jacob Jones University of California Riverside View all articles by this author Kevin Keegan Carnegie Museum of Natural History View all articles by this author Peter Kerr California Department of Food and Agriculture Plant Pest Diagnostics Center View all articles by this author Emma Kurstjens San Diego Natural History Museum View all articles by this author Jesse Laine Natural History Museum of Los Angeles County View all articles by this author Bethany Leach Stillwater Sciences View all articles by this author Socrates Letana University of California Davis View all articles by this author Valerie Levesque-Beaudin University of Guelph Centre for Biodiversity Genomics View all articles by this author Benjamin Maples California Department of Food and Agriculture Plant Pest Diagnostics Center View all articles by this author Martin Melia California Academy of Sciences View all articles by this author Joe Miller University of California Santa Cruz View all articles by this author Christiana Mojica San Diego Natural History Museum View all articles by this author Spencer Monckton University of Guelph Centre for Biodiversity Genomics View all articles by this author Denise Montelongo California Academy of Sciences View all articles by this author Michael Nance Natural History Museum of Los Angeles County View all articles by this author Michael Nee California Academy of Sciences View all articles by this author Sarah Nguyen California Academy of Sciences View all articles by this author Avas Pakrashi University of Guelph Centre for Biodiversity Genomics View all articles by this author Mikko Pentinsaari 0000-0001-7241-3873 Canadian National Collection of Insects Arachnids and Nematodes View all articles by this author Julia Perez University of California Riverside View all articles by this author Diana Phan California Academy of Sciences View all articles by this author S Pike University of California Berkeley View all articles by this author Kipp Pow Stillwater Sciences View all articles by this author Nomena Rasoarimalala 0009-0004-1498-1388 California Academy of Sciences View all articles by this author Sujeevan Ratnasingham University of Guelph Centre for Biodiversity Genomics View all articles by this author Sylvia Reyes Natural History Museum of Los Angeles County View all articles by this author Samantha Richey California Academy of Sciences View all articles by this author Orlando Romeo 0000-0002-4559-2199 California Academy of Sciences View all articles by this author Cristina Sandoval University of California Santa Barbara View all articles by this author Ken Schneider California Academy of Sciences View all articles by this author Michael Schweiker Stillwater Sciences View all articles by this author Katja Seltmann 0000-0001-5354-6048 University of California Santa Barbara View all articles by this author Stevie Steele Nature Collective View all articles by this author Nathan Tang Natural History Museum of Los Angeles County View all articles by this author Lauren Tham Essig Museum of Entomology View all articles by this author Wilfred Valtakis III University of California Davis View all articles by this author Matthew Van Dam California Academy of Sciences View all articles by this author Elise Vasquez California State University Monterey Bay College of Science Media Arts and Technology View all articles by this author Vanessa Verdecia Carnegie Museum of Natural History View all articles by this author David Wagner University of Connecticut View all articles by this author Michael Wall San Diego Natural History Museum View all articles by this author P. Signe White University of California Berkeley View all articles by this author Jakob Woodall Stillwater Sciences View all articles by this author Yanega Doug University of California Riverside View all articles by this author Evgeny Zakharov University of Guelph Centre for Biodiversity Genomics View all articles by this author Megan Barkdull Natural History Museum of Los Angeles County View all articles by this author Brian Brown Natural History Museum of Los Angeles County View all articles by this author Laura Melissa Guzman [email protected] Cornell University View all articles by this author Metrics & Citations Metrics Article Usage 996 views 383 downloads .FvxKWukQNSOunydq8rnd { width: 100px; } Citations Download citation Austin Baker, Brad Balukjian, Hilary Bayer, et al. DNA barcoding of more than one million insect specimens indicates that at least one third of California's insect biodiversity remains undiscovered. Authorea . 05 December 2025. 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