Isophthalamides of the formula (I) and salts thereof in which the symbols and indices are defined as follows: Q is Q 1 , Q 2 , Q 3 or Q 4 R 1 is (C 1 -C 6 ) -alkyl, halo- (C 1 -C 6 ) -alkyl or (C 3 -C 6 ) cycloalkyl, R 2 is (C 1 -C 6 ) -alkyl, R x is (C 1 -C 6 ) -alkyl, (C 1 -C 6 ) -alkyl-O- (C 1 -C 6 ) -alkyl or phenyl, RY is halogen, (C 1 -C 6 ) -alkyl or halo- (C 1 -C 6 ) -alkyl, R z is hydrogen, (C 1 -C 6 ) -alkyl or halo- (C 1 -C 6 ) -alkyl, X is halogen, (C 1 -C 6 ) -alkyl, halo- (C 1 -C 6 ) -alkyl, (C 3 -C 6 ) -cycloalkyl, R 1 O, R 2 (O) n S or R 1 O- (C 1 -C 6 ) -alkyl or R 2 S (O) n - (C 1 -C 6 ) -alkyl, Y is halogen, (C 1 -C 6 ) -alkyl, halo- (C 1 -C 6 ) -alkyl, R 1 O or R 2 (O) n S, Z is hydrogen, one of the following groups, each of which is substituted by s radicals from the group consisting of halogen, cyano, R 1 C(O), R 1 OC(O), R 1 O and R 2 (O) n S: (C 1 -C 6 ) -alkyl, (C 3 -C 6 ) -cycloalkyl, (C 3 -C 6 )-cycloalkyl- (C 1 -C 6 ) -alkyl, (C 1 -C 6 ) -alkyl-O- (C 1 -C 6 )-alkyl, (C 2 -C 6 ) -alkenyl, (C 2 -C 6 ) -alkenyl- (C 1 -C 6 )-alkyl, (C 2 -C 6 ) -alkynyl, (C 2 -C 6 ) -alkynyl- (C 1 -C 6 )-alkyl, (C 1 -C 6 ) -alkoxy, R 2 S (O) n- (C 1 -C 6 ) -alkyl, R 1 C (O) , R 1 OC(O), R 1 C(O)-(C 1 -C 6 )-alkyl, R 1 OC(O)-(C 1 -C 6 )-alkyl, R 1 NH- (C 1 -C 6 ) -alkyl, R 1 2 N- (C 1 -C 6 ) -alkyl, R 1 NHC (O) - (C 1 -C 6 ) -alkyl or R 1 2 NC (O) - (C 1 -C 6 ) -alkyl, or one of the following groups, each substituted by s radicals from the group consisting of halogen, (C 1 -C 6 ) -alkyl, halo- (C 1 -C 6 ) -alkyl, (C 1 -C 6 ) -alkoxy, halo-(C 1 -C 6 ) -alkoxy, R 1 C (O) and R 1 OC (O): phenyl, benzyl, phenyl, benzyl, heterocyclyl or heterocyclyl-(C 1 -C 6 )-alkyl, n is 0, 1 or 2, s is 0, 1, 2 or 3. Q is Q 1 , Q 2 , Q 3 or Q 4 R 1 is (C 1 -C 6 ) -alkyl, halo- (C 1 -C 6 ) -alkyl or (C 3 -C 6 ) cycloalkyl, R 2 is (C 1 -C 6 ) -alkyl, R x is (C 1 -C 6 ) -alkyl, (C 1 -C 6 ) -alkyl-O- (C 1 -C 6 ) -alkyl or phenyl, RY is halogen, (C 1 -C 6 ) -alkyl or halo- (C 1 -C 6 ) -alkyl, R z is hydrogen, (C 1 -C 6 ) -alkyl or halo- (C 1 -C 6 ) -alkyl, X is halogen, (C 1 -C 6 ) -alkyl, halo- (C 1 -C 6 ) -alkyl, (C 3 -C 6 ) -cycloalkyl, R 1 O, R 2 (O) n S or R 1 O- (C 1 -C 6 ) -alkyl or R 2 S (O) n - (C 1 -C 6 ) -alkyl, Y is halogen, (C 1 -C 6 ) -alkyl, halo- (C 1 -C 6 ) -alkyl, R 1 O or R 2 (O) n S, Z is hydrogen, one of the following groups, each of which is substituted by s radicals from the group consisting of halogen, cyano, R 1 C(O), R 1 OC(O), R 1 O and R 2 (O) n S: (C 1 -C 6 ) -alkyl, (C 3 -C 6 ) -cycloalkyl, (C 3 -C 6 )-cycloalkyl- (C 1 -C 6 ) -alkyl, (C 1 -C 6 ) -alkyl-O- (C 1 -C 6 )-alkyl, (C 2 -C 6 ) -alkenyl, (C 2 -C 6 ) -alkenyl- (C 1 -C 6 )-alkyl, (C 2 -C 6 ) -alkynyl, (C 2 -C 6 ) -alkynyl- (C 1 -C 6 )-alkyl, (C 1 -C 6 ) -alkoxy, R 2 S (O) n- (C 1 -C 6 ) -alkyl, R 1 C (O) , R 1 OC(O), R 1 C(O)-(C 1 -C 6 )-alkyl, R 1 OC(O)-(C 1 -C 6 )-alkyl, R 1 NH- (C 1 -C 6 ) -alkyl, R 1 2 N- (C 1 -C 6 ) -alkyl, R 1 NHC (O) - (C 1 -C 6 ) -alkyl or R 1 2 NC (O) - (C 1 -C 6 ) -alkyl, or one of the following groups, each substituted by s radicals from the group consisting of halogen, (C 1 -C 6 ) -alkyl, halo- (C 1 -C 6 ) -alkyl, (C 1 -C 6 ) -alkoxy, halo-(C 1 -C 6 ) -alkoxy, R 1 C (O) and R 1 OC (O): phenyl, benzyl, phenyl, benzyl, heterocyclyl or heterocyclyl-(C 1 -C 6 )-alkyl, n is 0, 1 or 2, s is 0, 1, 2 or 3. <EOS>