A 3-(2,chloro-3,3,4,4,4-pentafluoro-1-butenyl)-2,2-dimethyl-cycloproanecarboxylic acid ester of the formula ##STR1## in which R.sup.1 represents hydrogen, cyano or an alkyl, alkenyl or alkynyl radical with in each case up to 4 carbon atoms, andR.sup.2 represents a phenyl radical which is substituted by fluorine and/or by optionally fluorine-substituted C.sub.1 -C.sub.2 -alkylenedioxy and/or by optionally fluorine-substituted phenoxy, with the proviso that the radical R.sup.2 contains a total of at least one fluorine-substituent which possesses insecticidal and acaricidal activity.