Spiroheterocyclic thiofuran dione derivatives

Compounds of the formula I

• wherein
• X, Y and Z independently of each other are C1-4alkyl, C3-6cycloalkyl, C1-4haloalkyl, C1-4alkoxy, C2-C6alkenyl, C2-C6alkynyl, halogen, phenyl or phenyl substituted by C1-4alkyl, C1-4haloalkyl, halogen or cyano;
• m and n, independently of each other, are 0, 1, 2 or 3 and m+n is 0, 1, 2 or 3;
• G is hydrogen, a metal, ammonium, sulfonium or a latentiating group;
• A is sulfur;
• and
• R is hydrogen, C1-6alkyl, C1-6haloalkyl, C1-6cyanoalkyl, C2-C6alkenyl, C3-C6alkynyl, benzyl, C1-4alkoxy(C1-4)alkyl or C1-4alkoxy(C1-4)alkoxy(C1-4)alkyl;
• or
• an agrochemically acceptable salt or an N-oxide thereof.