The California Insect Barcoding Initiative: A million specimens and counting

The California Insect Barcoding Initiative aims to build a comprehensive DNA barcode reference library for all of California’s insect species by sequencing both freshly collected specimens from diverse habitats across the state and expertly identified material from natural history collections. To maximize biodiversity coverage, we sample across as many ecoregions as possible using a variety of collection methods. Our long-term Malaise trap network enables temporal sampling, allowing us to study phenology, monitor insect abundance, and model species accumulation over time. We have recently reached a major milestone by sequencing over one million insect specimens from field collections. These data have enabled us to map predicted species distributions for more than 40,000 unique Barcode Index Numbers (BINs), which we have used to assess large-scale biodiversity patterns and identify geographic gaps in sampling effort across the state. This growing dataset is not only transforming our understanding of California’s insect fauna, but also establishing a scalable framework for insect biodiversity monitoring in the face of global change. As we move beyond the first million, we are beginning to use these data to track ecological trends and inform long-term strategies for documenting and preserving insect diversity.