fungi 34 in hungarian ed l vajna mezogazdasagi konyvkiado page 119 budapest 1987 characteristically in opposition to diterpenes and monoterpenes triterpenes stigmasterol sitosterol squalene or ergosterol are not metabolized or are metabolized only after induction to a very small extent and nonspecifically by a microsomal oxidase preparation arising from the larvae of a moth spodoptera frugiperda j chem ecol 13 423 1987 the facts discussed above indicate that inhibitors of the enzymes participating of the biosynthesis of ergosterol have no effect on the microsomal enzymes of insects no other mechanism of action is known from the literature through which these inhibitors might exert an influence on the efficiency of pyrethroid type insecticides used against insects it has been recognized during our investigations that the insecticidal activity of pyrethroids was significantly enhanced by the addition of several fungicides inhibiting the biosynthesis of ergosterol the combined compositions according to the invention can be used in the common manner e g by dipping sprinkling spraying spreading fuming dusting bathing impregnating the packaging material and the like the amount applied depends on the good and in general amounts to 2 25 g hectare hereinafter abbreviated g ha or 0 10 2 g ha of active ingredient combination respectively calculated for 100 g of seed grains or.