This research project, within the framework of Action 10 of the DOMO of the POI Loire, aims to discover how to limit the risk of colonisation of prairial habitats invaded by invasive alien species on the Lake basin, in particular in order to reduce the economic impact of farmers who suffer the consequences with the loss of forage area. The second part aims to determine for an invasive species, juices, why the terrestrial form is more difficult to treat than the aquatic form. Finally, paths for biological control in the territory of the region will be developed.