Chemical senses play a key role in the adaptation of species to their environment, especially in insects. Changes in the sensory equipment of insects that have evolved from a terrestrial to an aquatic environment have long aroused the curiosity of scientists, but the mechanisms of sensory perception have never been studied in aquatic insects.This project aims to address this question using a chemical ecology approach (physicochemical analyses, electrophysiology, behavior) in the diving beetle Rhantus suturalis, a common species in Western European ponds and an important predator of mosquito larvae.