A method of combating and controlling insects, acarines, nematodes or molluscs which comprises applying to a pest, to a locus of a pest, or to a plant susceptible to attack by a pest an insecticidally, acaricidally, nematicidally or molluscicidally effective amount of a compound of formula (I) wherein Y is a single bond, C═O, C═S or S(O)m where m is 0, 1 or 2; and R1, R3, R2 and R8 are defined organic, groups, p is 0, 1, 2, 3 or 4 or salts or N-oxides thereof; novel compounds and composition's containing them are also provided.