Abstract: Combinations of compounds of the formula I ##STR1## in which R.sub.5 denotes H or CH.sub.3 ; R.sub.26 denotes CH.sub.3 or C.sub.2 H.sub.5 ; ##STR2## with a selected insecticide from the group comprising phosphoric acid esters, carbamates and carboxylic acid esters, or an insecticide of the formula II ##STR3## in which R.sup.1 denotes H or F, R.sup.2 denotes F, halogenoalkoxy, (substituted) phenoxy or (substituted) pyridyloxy and R.sup.3 denotes H or Cl, or an active compound from the group comprising azocyclotin, binapacryl, bensultap, bisclofentezin, buprofecin, cartap, cyromacin, endosulfan, ethoproxyfen, fenoxycarb, flubenzimin, hexythiazox, ethofenprox, 5-[4-(4-ethoxyphenyl)-4-methylpentyl]-2-fluoro-1,3-diphenyl ether, 3-(2-chlorophenyl)-3-hydroxy-2-(2-phenyl-4-thiazolyl)-propenenitrile and thiocyclam, with Bacillus thuringiensis or a nuclear-polyhedral or granulosis virus have surprising advantageous actions when used against harmful insects and acarides.