The Psyche project is a pan-European initiative led by the Wellcome Sanger Institute and involving 184 people across 34 countries with the goal of sequencing the genomes of all butterflies and moths in Europe. Roger Vila, principal investigator at the Institute of Evolutionary Biology (IBE), a joint centre of the Spanish National Research Council (CSIC) and Pompeu Fabra University (UPF), leads Psyche’s Lepidoptera collection node for Southwestern Europe.

The Human Genome Project laid the foundations for a revolution in our understanding of human health. Twenty-five years later, however, we still know the genome of only a tiny fraction of Earth’s species.

Since its launch in 2023, the project has already generated 1,000 butterfly and moth genomes. As a result, Lepidoptera are now at the cutting edge of biodiversity genomics, boasting the largest number of reference genomes for any animal (or eukaryotic) order. This open-access pan-European catalogue will transform our understanding of evolution and ecology, support conservation efforts, and foster advances in pest and invasive species management.

“Our goal for the coming years is twofold: on the one hand, to continue working toward completing the 11,000 genomes for all species, and on the other, to demonstrate what can be achieved with these genomes in terms of research and conservation,” says Roger Vila, principal investigator of the IBE’s Butterfly Diversity and Evolution Group (CSIC–UPF) and co-author of the study.

Why sequence butterflies and moths?

Lepidoptera are essential to ecosystem functioning: they act as herbivores, pollinators, and prey, and serve as key indicators of environmental health. Declines in butterfly populations are often an early warning sign of broader wildlife losses. In Europe, meadow butterfly populations declined by 36% between 2011 and 2020.

They also include many species of economic and agricultural importance, as several Lepidoptera are major pests of forests and crops.

“Genomics allows us to estimate population declines, connectivity between populations, and levels of inbreeding. Understanding the evolution of resilient species could help protect others,” Vila explains.

 Danaus chrysippus butterfly. Credit: Roger Vila.

Building on other large-scale biodiversity genome initiatives under the Earth BioGenome Project (EBP), in which the IBE (CSIC–UPF) also participates, the Psyche Project seeks to generate unprecedented genomic resources for Lepidoptera. To do so, it has brought together researchers, conservation professionals, industry specialists, and engaged citizen scientists, including amateur entomologists.

“The Psyche project represents an exemplary collaborative effort among hundreds of scientists across Europe. In Spain, the project involves the Institute of Evolutionary Biology, the Universities of A Coruña, Murcia, Valencia, Oviedo, Vigo, and Barcelona, the Institute of Natural Products and Agrobiology (IPNA), the Botanical Institute of Barcelona, the Granollers Museum of Natural Sciences, the Zerynthia Association, and numerous naturalists. We all share a common goal: to understand and protect the immense diversity of butterflies and moths,” Vila says.

The project is expected to enable effective biodiversity management and policy-making at both local and global scales.

A new window into the evolution of Lepidoptera

Lepidoptera exhibit extraordinary diversity: they account for 10% of all eukaryotic species on the planet. Some species can synthesise toxins, camouflage within their surroundings, migrate thousands of kilometres, or adapt to extreme temperatures. They are also key ecosystem components due to their roles as pollinators, herbivores, and prey for insectivorous animals.

Studying their evolutionary adaptations could shed light on the history and biodiversity of butterflies and moths, which originated more than 200 million years ago. Moreover, the chromosomal restructuring mechanisms that have shaped their evolution may provide insights into evolutionary genetics and health in many animal species.

“Understanding the adaptive history of Lepidoptera could be crucial for their conservation in the face of the climate crisis,” Vila notes.

Referenced article:

Wright, Charlotte J., Niklas Wahlberg, Roger Vila, Marko Mutanen, Pável Matos-Maraví, Kay Lucek, Irena Kleckova, et al. (2025). Project Psyche: Reference Genomes for All Lepidoptera in Europe. Trends in Ecology & Evolution. https://doi.org/10.1016/j.tree.2025.10.007