Pesticidal pyrimidine compounds

A compound having the structural formula ##STR9## wherein X.sup.1 and X.sup.2 are the same and each represents an oxygen atom;

• a group S(O).sub.n in which n is 0, 1 or 2;
• or a group CO, CH.sub.2 or NR in which R represents a hydrogen atom or a C.sub.1-6 alkyl group;
• R.sup.1 and R.sup.10 are the same or different and each represents a hydrogen atom or a halogen atom;
• R.sup.2 and R.sup.9 are the same or different and each represents a hydrogen atom, a halogen atom or a cyano, nitro, C.sub.1-6 alkyl, haloC.sub.1-6 alkyl, C.sub.1-6 alkoxy, C.sub.1-6 alkylthio, amino, mono- or di(C.sub.1-6 alkyl)amino, C.sub.1-6 alkoxyC.sub.1-6 alkyl, haloC.sub.1-6 alkoxyC.sub.1-6 alkyl or (C.sub.1-6 alkoxy) carbonyl group;
• R.sup.3 and R.sup.8 are the same or different and each represents a hydrogen atom, a chlorine atom, or a C.sub.1-6 alkyl, haloC.sub.1-6 alkyl, haloC.sub.1-6 alkoxy, haloC.sub.1-6 alkylthio, haloC.sub.2-6 alkenyl, haloC.sub.2-6 alkynyl, haloC.sub.1-6 alkoxyC.sub.1-6 alkyl, (haloC.sub.1-6 alkoxy) carbonyl, haloC.sub.1-6 alkylsulphinyl, haloC.sub.1-6 alkylsulphonyl, nitro or cyano group;
• R.sup.4 and R.sup.7 are the same or different and each represents a hydrogen atom, a halogen atom or a C.sub.1-6 alkyl or C.sub.1-6 alkoxy group;
• R.sup.5 represents a hydrogen atom, a halogen atom, or a cyano, C.sub.1-6 alkyl, haloC.sub.1-6 alkyl, C.sub.1-6 alkoxy, C.sub.1-6 alkylthio, C.sub.1-6 alkylsulphinyl or phenyl group;
• and
• R.sup.6 represents a hydrogen atom or, when R.sup.5 is hydrogen, a C.sub.1-6 alkyl group;
• provided that at least one of R.sup.3 and R.sup.8 is other than hydrogen.