Preliminary Study on the Inhibition Efficiency of Detoxification Enzymes by Unsaturated Fatty Acids from Vegetable Oils Based Synergists in Pest Control ☆

In order to determine the mechanism action of synergist when combined with pesticides to enhance the pest control, the inhibitory effect of the vegetable oil based synergists on certain digestion and detoxification enzymes in the insect resistant to Bt and Imidacloprid insecticides was investigated. As the results, a mixture of potassium oleate and potassium linoleate (S1) has inhibitory effect of digestive enzymes aminopeptidase N (APN) of diamondblack moth Plutella xylostella (IC50 ¬= 1,06 mg/ml); and methyl oleate (S2) strongly inhibits the detoxification enzyme cytochrome P450-monooxygenase (CYP) of brown planthoppers Nilaparvata lugens Stal. (IC50 ¬= 1,02 mg/ml). Significantly, the synergistic effect could be observed for both mixture products Bt + S1 and Imidacloprid + S2, thus they showed the stronger inhibition (IC50 = 0,55 mg/ml for APN and 0,95 mg/ml for CYP, respectively) than insecticides used alone.