European Scientists Unite to Advance Butterfly Genomics towards understanding and preserving biodiversity

Montpellier, France — LepEU1 (European Lepidopteran Population Genomics Consortium) studies diversity patterns and local adaptation of butterflies and moths over space and time through a comparative population genomics approach. From 12 to 16 May, 21 researchers from across Europe2 convened in Montpellier for the first LepEU Workshop, a meeting dedicated to coordinating collecting efforts and discussing the research goals and future applications in conservation and pest management. The event was supported by the European Cooperation in Science and Technology (COST) Action 10kLepGenomes. 

Butterflies are a key study group to showcase the utility of genomic knowledge to understand and protect biodiversity. Butterfly ecology is well documented in research and museums, some species have great economic impact (pollinators and pests), or serve as key bioindicators for conservation. The size of their genomes allow efficient reference genome assembly. They are the target of active citizen science programmes and are powerful for outreach. LepEU aims at leveraging all the merits of butterflies to foster biodiversity research using population genomic approaches. 

Key Outcomes of the Workshop and LepEU Milestones 

1. Sampling Priorities: Participants agreed to prioritize the completion of sampling of populations across Europe and Whole Genome Sequencing (WGS) for 13 core butterfly species — with top priority on Pieris napi, Anthocharis cardamines, Pararge aegeria, and Maniola jurtina. Meanwhile, sampling of additional species, including grassland indicators and day-flying moths, will continue throughout the season. 
2. Standardized Protocols: The role of national coordinators was established for each participating country to facilitate specimens’ collection together with local researchers. Shared protocols for sampling, preparation and metadata archiving were adopted to improve standardization and interoperability of generated datasets with other major biodiversity initiatives, such as the Darwin Tree of Life Project (DTOL) and the European Reference Genome Atlas (ERGA). 
3. Hands-On Laboratory Work: During the meeting, and coordinated by Dr Mathieu Joron (CNRS, France), workshop participants conducted approximately 500 DNA extractions in the Centre d’Ecologie Fonctionnelle et Evolutive laboratories. The samples corresponded to 21 species collected by 15 researchers in 34 localities across 7 European countries. The DNA extractions will be ready for WGS in the coming months, representing a milestone for LepEU. 

A Vision for 2030 

Looking to the future, the LepEU consortium outlined an ambitious roadmap: 

• Expanding Species Coverage: The initiative will now extend to all 17 butterfly species used in the European Grassland Butterfly Indicator, as well as 10 widespread and easily identifiable moth species, thus contributing to the EU Pollinators Initiative. 

• Genetic Diversity Monitoring: The project will generate and analyze genomic data necessary to estimate genetic diversity indicators, as required under the 2022 Kunming-Montreal Global Biodiversity Framework. 

• Temporal Insights via Museum Samples: A key goal will be to assess changes in genetic diversity over time driven by anthropogenic activities using historical specimens archived at museum collections. 

• Capacity Building: A training school focused on analyzing WGS data and targeting early career researchers will be organized in 2026, offering hands-on practice to analyze WGS data for comparative population genomics. 

• Securing Support: The consortium will actively seek funding to support the continued sampling, sequencing, and analysis efforts across Europe. 

Dr Patrícia Beldade summarized the collective sentiment: “This meeting has strengthened our scientific vision and built the foundations for a lasting collaborative effort. By combining resources, expertise and data, we are paving the way for an unprecedented understanding of butterfly population genomics in Europe.”

Find out more at https://lepeu.github.io/  

Contact details: 

LepEU leaders 

Christopher Wheat, Stockholm University, Sweden. Email: [email protected]. Phone: +468164020 

Mathieu Joron, Centre d’Ecologie Fonctionnelle et Evolutive, CNRS Montpellier, France. Email: [email protected]. Phone: +33/0 467613203 

Patrícia Beldade, Centre for Ecology, Evolution and Environmental Changes, Lisbon University, Portugal. Email: [email protected]. Phone: +351 217500000