VEILLAT Loïs

As a postdoctoral researcher in ecology, I am interested in the impacts of forest management on biodiversity, which I study using molecular biology approaches (environmental DNA) and ecological analyses. My work spans from fieldwork to laboratory work, through to data analysis and modelling.

Positions and Internships

• 04/2025–Present: Postdoctoral researcher in the Mediterranean Forest Ecology unit.
• 09/2023–08/2024: Temporary Teaching and Research Assistant (ATER) at the University of Orléans.
• 10/2020–04/2024: PhD candidate in the Forest Zoology Research Unit, INRAE Orléans.
• 01/2020–06/2020: Master’s internship (M2) in the Laboratory of Microorganisms in Extreme Environments (IFREMER, Plouzané): “Study of the phylogenetic and functional diversity of the phylum Bathyarchaeota in deep-sea sediments using a metagenomics approach.”
• 05/2019–07/2019: Master’s internship (M1) at CHU Gabriel Montpied (Clermont-Ferrand): “Survey of protein interaction networks in Homo sapiens for the investigation of multifactorial diseases.”
• 02/2018–06/2018: Voluntary internship in the Laboratory of Microorganisms, Genome and Environment (Clermont-Ferrand): “Study of pesticide and parasite interactions on the gut microbiota of honey bees.”

Education

• 04/2024: PhD in Ecology – "Genomic approaches for the biodetection of invasive forest insects". Supervised by Géraldine Roux and Carlos Lopez-Vaamonde, University of Orléans.
• 07/2020: Master’s degree in Bioinformatics, specialisation in Biological Data Analysis and Modelling, University of Clermont Auvergne.
• 07/2018: Bachelor’s degree in Biology, specialisation in Organismal and Population Biology in Ecosystems, University of Clermont Auvergne.
• 07/2014: French Baccalauréat, Science track (S series), Lycée du Castella, Pamiers (09).
• Research Work

Postdoctoral Project Summary
“Response of insect and fungal diversity to forest management history: comparison of classical and environmental DNA-based approaches”
In the face of major challenges related to biodiversity assessment under global change, this postdoctoral project aims to evaluate the impact of forest management intensity on the diversity of biotic communities. The study tests whether two forest biodiversity indicator taxa — insects and fungi — show similar patterns of taxonomic, functional and phylogenetic diversity in ancient beech-fir forests (with continuous presence since at least 1860) that exhibit varying levels of anthropogenic disturbance: unmanaged forests (>100 years), formerly managed forests (>50 years), and currently managed forests.Framed within the conceptual context that higher biodiversity in less disturbed forests may buffer functional declines caused by environmental fluctuations, the project seeks to generate and compare diversity indicators for these two key ecological groups. These indicators will be obtained using both classical inventory methods (sampling and taxonomic identification by experts) and innovative environmental DNA (eDNA) metabarcoding approaches. The findings are expected to contribute to the development of multifactorial biodiversity indicators for forest-dwelling organisms providing multiple ecosystem services — a growing conservation priority in recent decades.

PhD Thesis Summary
“Genomic approaches for the biodetection of invasive forest insects”
Biological invasions, especially by wood-boring insects such as cerambycids, are steadily increasing due to climate change and intensifying global trade. Transported primarily through the international timber trade, these insects can establish themselves in new ecosystems where they often lack natural predators. Once established, they can cause significant damage to forests and urban areas, posing serious threats to biodiversity, the economy, and ecosystem health. Consequently, rigorous monitoring and management are essential to prevent and mitigate their impacts.This PhD had three main objectives:(i) To evaluate the efficiency of metabarcoding — a method that allows rapid and simultaneous identification of multiple insect species collected in a single trap — using Oxford Nanopore’s MinION® sequencer. This portable and cost-effective device offers greater accessibility compared to competing technologies.(ii) To build a reference DNA barcode library for cerambycids collected across Europe, providing the scientific community with a robust dataset for reliable molecular identification.(iii) To investigate the genetic structure of invasive populations of Xylotrechus stebbingi, an exotic species introduced into the Mediterranean Basin, to better understand its invasion dynamics.

Regarding the first objective, our results demonstrated that the MinION® sequencer performed well for the rapid detection and identification of invasive species, comparable to Illumina® and IonTorrent technologies. The study also highlighted that trap preservation methods are a critical prerequisite for reliable species detection.For the second objective, we assembled 2,928 DNA barcode sequences covering 147 cerambycid species, representing over 79% of the 185 species trapped using multi-pheromone lures across Europe. This new database can be used for accurate identification in future DNA barcoding or metabarcoding analyses.Finally, in the third part of the thesis, we showed that the invasion of Xylotrechus stebbingi in the Mediterranean Basin resulted from multiple introduction events, likely linked to maritime trade, rather than a single introduction followed by local spread. These findings suggest that this highly polyphagous and potentially invasive species could spread to new regions globally in the coming years via maritime transport. Therefore, increased vigilance in port areas is essential to help prevent its further spread.

Publications

• Veillat, L., Boyer, S., Querejeta, M., Magnoux, E., Roques, A., Lopez-Vaamonde, C., & Roux, G. (2024). Benchmarking three DNA metabarcoding technologies for efficient detection of non-native cerambycid beetles in trapping collections. NeoBiota, 96, 237–259. https://doi.org/10.3897/neobiota.96.130195
• Veillat, L., Cocquempot, C., Streito, J.-C., Pierre, E., Genson, G., Rasplus, J.-Y., Cruaud, A., Roux, G., Lopez-Vaamonde, C. Establishment of a molecular barcode database for cerambycids captured with multipheromone traps in Europe (in prep).
• Veillat, L., Cocquempot, C., Gauthier, J., Roques, A., Lopez-Vaamonde, C., Roux, G. Population genetic structure of Xylotrechus stebbingi along the North Mediterranean Basin (in prep).
• Roques, A., Ren, L., Rassati, D., Shi, J., Akulov, E., Audsley, N., Auger-Rozenberg, M.-A., Avtzis, D., Battisti, A., Bellanger, R., Bernard, A., Bernadinelli, I., Branco, M., Cavaletto, G., Cocquempot, C., Contarini, M., Courtial, B., Courtin, C., Denux, O., … Veillat, L., Millar, J. G. (2023). Worldwide tests of generic attractants, a promising tool for early detection of non-native cerambycid species. NeoBiota, 84, 169–209. https://doi.org/10.3897/neobiota.84.91096
• Blot, N., Veillat, L., Rouzé, R., & Delatte, H. (2019). Glyphosate, but not its metabolite AMPA, alters the honeybee gut microbiota. PLOS ONE, 14(4), e0215466. https://doi.org/10.1371/journal.pone.0215466

Teaching and Supervision

UNIVERSITY OF ORLÉANS

• Population Genetics in Natural Environments (Bachelor, 21h practicals)
• Evolutionary Biology and Population Genetics (Master 1, 3h tutorials and 8h practicals)
• Population Dynamics and Structure (Master 2, 3h tutorials)
• Invasion Biology (Master 2, 3h tutorials)
• Biodiversity (Bachelor, 4h tutorials)
• Plant Protection (Master 1, 24h practicals)
• Ethology (Bachelor, 16h practicals)
• Diversity and Evolution of Life (Bachelor 1, 56h practicals)
• Classification of the Animal and Plant Kingdoms (Bachelor 2, 8h practicals)
• Evolutionary Biology (Bachelor 3, 24h practicals and 16h tutorials)
• Population Biology (Bachelor 3, 8h tutorials)
• Field Experience – Fauna (Bachelor 3, 45h practicals)
• Ecology (Bachelor 2, 12h practicals)
• Ecological Transition (Bachelor 1, 20h tutorials)

STUDENT SUPERVISION

• Ms Juliette Carpentier, Master 1 internship, two months (May–June 2021)
• Mr Mathieu Plateau, voluntary internship, two months (May–June 2022)
• Mr Clément Beaumont, voluntary internship, one month (July 2022)
• Ms Camille Meunier, Master 1 internship, two months (January–February 2023)

Skills

BIOINFORMATICS

• Programming in Python
• Data modelling and biostatistics in R
• NGS data analysis
• Metabarcoding, RNAseq, Bash scripting
• High-performance computing clusters
• Biological databases
• Strong understanding of biological research questions and the ability to develop bioinformatics solutions

BIOLOGY

• Insect experimentation (bees and Cerambycidae)
• Forest insect trapping techniques
• Fieldwork
• Ecology, ethology
• Molecular barcoding, DNA extraction, PCR
• Microbiota, genomics
• Sequencing library preparation
• Statistical analysis with R (mixed models)

Conferences and Presentations

NATIONAL CONFERENCES / SYMPOSIA

• Doctorales de la forêt, Blois (France), 4–5 April 2023 – Oral presentation
• Groupe des Entomologistes Forestiers Francophones (GEFF), Lamotte-Beuvron, 26–29 September 2022 – Oral presentation
• GEFF, Arcachon, 28–30 September 2021 – Oral presentation
• Annual Scientific Meeting 2020 – Oral presentation
• OCCIGEN Seminar, Castelnau-de-Montmirail, 17–18 June 2025 – Oral presentation

INTERNATIONAL CONFERENCES / SYMPOSIA

• HOMED Final Annual Meeting, Lisbon, Portugal, 12–14 September 2022 – Oral presentation
• International Union of Forest Research Organizations (IUFRO), Lisbon, Portugal, 6–9 September 2022 – Poster
• XXVI International Congress of Entomology (ICE), Helsinki, Finland, 17–22 July 2022 – Oral presentation
• Environmental and Agronomical Genomics Symposium, Tours, France, 27–29 October 2021 – Poster
• IFOPE Webinar – Invasive Forest Pests in Eurasia, 12 October 2021 – Oral presentation