New oxime ethers and pesticidal and herbicidal preparations containing them are disclosed. The oxime ethers correspond to the formula ##SPC1##Wherein R.sub.1 is a hydrogen atom or a lower alkyl radical; R.sub.2 is an aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic radical; or wherein R.sub.1 and R.sub.2 form part of a saturated or unsaturated carbocycle or a 5-, 6- or 7-membered heterocycle; R.sub.3 is nitro, trifluoromethyl, formyl, lower carbalkoxy, sulfamyl or mono- or di-lower alkyl fulfamyl radical; R.sub.4- and R.sub.5 each is a hydrogen or halogen atom, an amino, mono- or di-lower alkyl amino, lower alkoxy, cycloalkoxy, lower alkylthio, nitro, lower carbalkoxy, arylthio, lower aralkylthio or lower alkyl group, or 5-, 6- or 7-membered heterocycle.