Pesticidal as a pesticide against whitefly, Lepidoptera and certain fungi is provided of compound of general formula (I) ##STR1## or a salt thereof is provided, in which n represents an integer from 0 to 4; m represents an integer 0 or 1;each R independently represents a halogen atom or a nitro, cyano, hydroxyl, alkyl, alkenyl, haloalkyl, haloalkenyl, alkoxy, haloalkoxy, haloalkenoxy, amino, alkylamino, dialkylamino, alkoxycarbonyl, carboxyl, alkanoyl, alkylthio, alkylsulphinyl, alkylsulphonyl, carbamoyl, alkylamido, cycloalkyl, aryl or aralkyl group;R.sup.1 and R.sup.2 each independently represent an optionally substituted alkoxy group or together represent a group .dbd.O, .dbd.S or .dbd.N--OR.sup.9, where R.sup.9 represents a hydrogen atom or an optionally substituted alkyl group;R.sup.3 represents a hydroxyl group, or a group --OL where L is a leaving group, or a group which in vivo is transformed into a group --OL.sup.1 where L.sup.1 is a leaving group;R.sup.7 and R.sup.8 independently represent an optionally substituted alkoxy group or together represent a group .dbd.O, .dbd.S or .dbd.N--OR.sup.9, where R.sup.9 is as previously defined;wherein R.sub.4 and R.sub.5 independently represent a halogen atom or an optionally substituted alkyl or alkenyl group, or together with the interjacent carbon atom represent an optionally substituted cycloalkyl or cycloalkenyl ring; andA represents a straight or branched chain alkyl or alkenyl group, which may be optionally substituted, an acyclic carbon chain of which links the 3 position of the naphthalene ring shown and the moiety --CHR.sup.4 R.sup.5 and wherein A does not include a quaternary carbon atom in that chain; andwherein the total number of carbon atoms in the longest carbon chain running from the 3-position of the naphthalene ring shown is no more than 8.