A compound of formula wherein R 2 is C 1 -C 6 haloalkyl, C 2 -C 6 haloalkenyl or C 1 -C 4 haloalkylsulfonyl; R 6 is C 1 -C 6 alkyl; Q is a radical selected from the group consisting of formula Qa and Qb wherein the arrow denotes the point of attachment to the pyrimidinone ring; and wherein A represents CH or N; X is S, SO, SO 2 or SO; R 1 is C 1 -C 4 alkyl or C 3 -C 6 cycloalkyl-C 1 -C 4 alkyl; Q 1 is hydrogen, halogen, C 1 -C 6 haloalkyl, C 3 -C 6 cycloalkyl, C 3 -C 6 cycloalkyl monosubstituted by cyano, C 1 -C 6 cyanoalkyl, C 1 -C 6 cyanoalkoxy, C 1 -C 6 haloalkoxy, -N(R 4) 2, -N(R 4)COR 5, -N(R 4)CON(R 4) 2, (oxazolidin-2-one)-3-yl or 2-pyridyloxy; or Q 1 is a five- to six-membered aromatic ring system linked via a ring carbon atom to the ring which contains the substituent A, said ring system is unsubstituted or is mono- or polysubstituted by substituents selected from the group consisting of halogen, cyano, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy, C 1 -C 4 haloalkoxy, C 1 -C 4 alkylsulfanyl, C 1 -C 4 alkylsulfinyl and C 1 -C 4 alkylsulfonyl; and said ring system can contain 1, 2 or 3 ring heteroatoms selected from the group consisting of nitrogen, oxygen and sulphur, where said ring system may not contain more than one ring oxygen atom and not more than one ring sulfur atom; or Q 1 is a five-membered aromatic ring system linked via a ring nitrogen atom to the ring which contains the substituent A, said ring system is unsubstituted or is mono- or polysubstituted by substituents selected from the group consisting of halogen, cyano, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy, C 1 -C 4 haloalkoxy, C 1 -C 4 alkylsulfanyl, C 1 -C 4 alkylsulfinyl and C 1 -C 4 alkylsulfonyl; and said ring system contains 1, 2 or 3 ring heteroatoms selected from the group consisting of nitrogen, oxygen and sulphur, where said ring system contains at least one ring nitrogen atom and may not contain more than one ring oxygen atom and not more than one ring sulfur atom; R 3 is hydrogen, halogen or C 1 -C 4 alkyl; R 4 is independently hydrogen, C 1 -C 4 alkyl or C 3 -C 6 cycloalkyl; R 5 is C 1 -C 6 alkyl, C 1 -C 6 haloalkyl or C 3 -C 6 cycloalkyl; or an agrochemically acceptable salt, stereoisomer, enantiomer, tautomer or N-oxide of a compound of formula I. R 2 is C 1 -C 6 haloalkyl, C 2 -C 6 haloalkenyl or C 1 -C 4 haloalkylsulfonyl; R 6 is C 1 -C 6 alkyl; Q is a radical selected from the group consisting of formula Qa and Qb wherein the arrow denotes the point of attachment to the pyrimidinone ring; and wherein A represents CH or N; X is S, SO, SO 2 or SO; R 1 is C 1 -C 4 alkyl or C 3 -C 6 cycloalkyl-C 1 -C 4 alkyl; Q 1 is hydrogen, halogen, C 1 -C 6 haloalkyl, C 3 -C 6 cycloalkyl, C 3 -C 6 cycloalkyl monosubstituted by cyano, C 1 -C 6 cyanoalkyl, C 1 -C 6 cyanoalkoxy, C 1 -C 6 haloalkoxy, -N(R 4) 2, -N(R 4)COR 5, -N(R 4)CON(R 4) 2, (oxazolidin-2-one)-3-yl or 2-pyridyloxy; or Q 1 is a five- to six-membered aromatic ring system linked via a ring carbon atom to the ring which contains the substituent A, said ring system is unsubstituted or is mono- or polysubstituted by substituents selected from the group consisting of halogen, cyano, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy, C 1 -C 4 haloalkoxy, C 1 -C 4 alkylsulfanyl, C 1 -C 4 alkylsulfinyl and C 1 -C 4 alkylsulfonyl; and said ring system can contain 1, 2 or 3 ring heteroatoms selected from the group consisting of nitrogen, oxygen and sulphur, where said ring system may not contain more than one ring oxygen atom and not more than one ring sulfur atom; or Q 1 is a five-membered aromatic ring system linked via a ring nitrogen atom to the ring which contains the substituent A, said ring system is unsubstituted or is mono- or polysubstituted by substituents selected from the group consisting of halogen, cyano, C 1 -C 4 alkyl, C 1 -C 4 haloalkyl, C 1 -C 4 alkoxy, C 1 -C 4 haloalkoxy, C 1 -C 4 alkylsulfanyl, C 1 -C 4 alkylsulfinyl and C 1 -C 4 alkylsulfonyl; and said ring system contains 1, 2 or 3 ring heteroatoms selected from the group consisting of nitrogen, oxygen and sulphur, where said ring system contains at least one ring nitrogen atom and may not contain more than one ring oxygen atom and not more than one ring sulfur atom; R 3 is hydrogen, halogen or C 1 -C 4 alkyl; R 4 is independently hydrogen, C 1 -C 4 alkyl or C 3 -C 6 cycloalkyl; R 5 is C 1 -C 6 alkyl, C 1 -C 6 haloalkyl or C 3 -C 6 cycloalkyl; or an agrochemically acceptable salt, stereoisomer, enantiomer, tautomer or N-oxide of a compound of formula I.