A compound of formula: CXY.dbd.CH--CR.sup.1 R.sup.2 --CH.sub.2 OCH.sub.2 R wherein X and Y are each selected from hydrogen and halogen, R.sup.1 and R.sup.2 are each lower alkyl of up to four carbon atoms, or together with the adjacent carbon atom form a cycloalkyl group of up to six carbon atoms, and R represents a phenoxy- or benzyl-substituted phenyl group which may optionally be substituted with fluorine. The compounds are useful for combating insect pests.