The present invention relates to novel imidazoline derivatives and their use as insecticidal, acaricidal, molluscicidal and nematocidal agents. The invention also extends to insecticidal, acaricidal, molluscicidal and nematicidal compositions comprising such imidazoline derivatives, and to methods of using such derivatives and/or compositions to combat and control insect, acarine, mollusc and nematode pests. A compound of formula (I): and the salts and N-oxides thereof.