Séminaire Ecobio - Eugène Maurey (Univ. Lorraine) - OSERen, Salle De Conférences, RDC Bât.14B, Campus De Beaulieu De L'Université De Rennes

Pest control in agricultural systems based on pesticide use is an unsustainable method over time and harmful to both biodiversity and human health. One of the most sustainable alternatives is to base crop protection on the pest control service provided by populations of natural predators. Soil arthropod predator communities make up a large part of these natural predator populations. These communities include several taxonomic groups such as ground beetles (Carabidae), rove beetles (Staphylinidae), and spiders (Araneae). Understanding how to infer the pest control is a key challenge for promoting this ecosystem service in agricultural landscapes. To estimate this service provided by these communities, we assume that a functional description of individuals is the most appropriate approach. We conducted a literature review on functional traits in soil arthropod predator communities. We found that body size is a functional trait shared across taxonomic groups that can be used to predict the size of prey consumed. Based on this result, we aim to identify which metrics derived from the functional description of individuals can be calculated for these predator populations to best infer their pest control service. We test the relevance of these metrics by comparing them with a second inference approach based on energy flux modeling within trophic networks. We found that both approaches converge in predicting predation function. However, the results also raise questions about the link between predation function and regulation service. This work is a first step toward identifying which metrics can be used to infer the pest control potential by a multi-taxonomic functional assemblage of soil arthropod predators.