The present invention relates to pyrimidinium compounds of formula (I), to the stereoisomers, salts, tautomers and N-oxides thereof, their mixtures and to compositions comprising such compounds or mixtures. The invention also relates to methods and uses of these pyrimidinium compounds and of compositions thereof, for combating and controlling animal pests. Furthermore, the invention relates also to pesticidal methods of applying such substituted pyrimidinium compounds. The pyrimidinium compounds of the present invention are defined by the following general formula (I), wherein R
