Abstract: A pesticidal compound of formula I: ##STR1## in which formula: either R.sup.1 is hydrogen and R.sup.2 represents a cyclopropyl group or R.sup.1 and R.sup.2 each represent an alkyl group, which alkyl groups may be the same or different;Ar.sub.A represents an optionally substituted phenyl or naphthyl group;Ar.sub.B represents a phenoxy, phenyl, benzyl or benzoyl-substituted phenyl group which is optionally further substituted;the configuration of the groups Ar.sub.A --CR.sup.1 R.sup.2 and --CH.sub.2 Ar.sub.B about the double bond being mutually trans.Preferably Ar.sub.A is a substituted phenyl group; more preferably being substituted at the 4-(para) position by halogen, alkoxy or haloalkyl.Further provided is a process for the preparation of a pesticidal compound of formula I in which a compound comprising a moiety ##STR2## and a compound comprising a moiety Ar.sub.B -- are reacted together forming a link --CH.dbd.C(F)CH.sub.2 -- between ##STR3## and Ar.sub.B in the compound of formula I.

Abstract: A pesticidal compound, suitable for combating soil borne insect pests has formula I: ##STR1## in which formula: Ar.sub.A represents a phenyl or naphthyl group optionally substituted by one or more groups selected from halogen, alkoxy, haloalkoxy, methylenedioxy, C.sub.1 -C.sub.6 alkyl and C.sub.1 -C.sub.6 haloalkyl; andAr.sub.B represents a phenoxy, phenyl, benzyl or benzoyl-substituted phenyl group which is optionally further substituted;the configuration of the aryl cyclopropyl group and the group CH.sub.2 Ar.sub.B about the double bond being mutually trans.