Toxicological and biochemical interactions of the fungal metabolites fusaric acid and kojic acid with xenobiotics in Heliothis zea (F.) and Spodoptera frugiperda (J.E. Smith)

Abstract

The effect of coapplying the fungal metabolites kojic acid and fusaric acid with selected mycotoxins, plant allelochemicals, and insecticides in diets of caterpillars was tested. Kojic acid synergized the toxicity of aflatoxin B 1 to both Heliothis zea (F.) and Spodoptera frugiperda (J. E. Smith). Fusaric acid synergized the toxicity of some trichothecenes to both insect species. Fusaric acid also synergized the toxicity of the allelochemicals gossypol and 6-methoxy-2-benzoxazolinone to H. zea, but not S. frugiperda. Malathion toxicity was antagonized by both kojic acid and fusaric acid, while pyrethrin toxicity was synergized by kojic acid in both insect species. Both compounds inhibited 4-nitroanisole O-demethylation in vitro and in vivo in both insect species. The apparent interaction of both compounds with unspecific monooxygenases as an explanation of their synergistic properties is discussed.