Compounds of the formula ##STR1## wherein R.sub.1 represents cyclohexyl, cyclohexyloxy or the ##STR2## BEING BONDED TO THE PHENYL NUCLEUS, R.sub.2 represents hydrogen, C.sub.1 -C.sub.3 -alkyl, R.sub.3 represents --COOH, (C.sub.1 -C.sub.5 -alkoxy)carbonyl, (C.sub.3 -C.sub.5 -alkenyloxy)carbonyl, (C.sub.3 -C.sub.5 -alkinyloxy)carbonyl, cyclohexyloxycarbonyl, phenoxycarbonyl, (C.sub.3 -C.sub.5 -haloalkenyloxy)carbonyl, the cyano group, a carbamoyl group which is mono- or disubstituted by C.sub.1 -C.sub.5 -alkyl, C.sub.3 -C.sub.5 -alkenyl or C.sub.3 -C.sub.5 -alkinyl, it being possible for the substituents of the carbamoyl group together with the nitrogen atom to which they are bonded to form a saturated 5- or 6-membered heterocyclic ring which can contain in addition an oxygen, a sulphur, or a further nitrogen atom, R.sub.4 represents hydrogen, methyl, or ethyl, R.sub.5 represents C.sub.1 -C.sub.3 -alkyl, formyl, or acetyl, R.sub.6 represents hydrogen or C.sub.1 -C.sub.3 -alkyl, R.sub.7 represents hydrogen, halogen, C.sub.1 -C.sub.5 -alkoxy or C.sub.1 -C.sub.5 -alkyl, and R.sub.8 represents halogen, methyl, or ethyl, and their use in pest control are disclosed.