The use of a compound of formula Iwherein Y is a single bond, C═O, C═S or S(O)m where m is 0, 1 or 2 the ringis a 6-membered aromatic or is a 5 or 6 membered heteroaromatic ring Z and Z′ are joined by a single or a double bond and are ═C— or —N— provided that both are not N Ra, R1, R2, R3, R3a, R4 and R8 are specified organic groups n is 2, 3 or 4 and p is 0-4 or salts or N-oxides thereof or compositions containing them in controlling insects, acarines, nematodes or molluscs. Novel compounds are also provided.
