Synergistic Effect of Sesame Oil on Chlorantraniliprole Toxicity and Detoxifying Enzymes Activity against Fall Armyworm, Spodoptera frugiperda (J.E. Smith)

The present study aimed to investigate the toxicity and synergistic effect of binary mixtures containing chlorantraniliprole and sesame oil at different ratios against second and third instar larvae of fall armyworm (FAW), Spodoptera frugiperda. The toxicity of different concentrations (LC25 and LC50) of chlorantraniliprole with or without sesame oil (1, 2.5 and 5 per cent) on second and third instar larvae of FAW was determined using the leaf discdip bioassay method. A combination of chlorantraniliprole LC50 plus sesame oil 2.5 per cent has resulted in 74.42 and 81.81 per cent larval mortality on the second and third instars larvae of FAW, respectively. The mortality percentage was 1.52 and 1.57 fold higher than the single effect for the second and third instars of FAW, respectively. These results showed that this combination exhibited high potentiating synergism in both the instars of FAW larvae under laboratory conditions. The activity of Carboxyl Esterase (CarE), Mixed Function Oxidase (MFO) and Glutathione-STransferase (GST) were found to be lesser in chlorantraniliprole LC50 plus sesame oil 2.5 per cent combinations than in single toxicity treatments. Therefore, sesame oil showed good synergism with chlorantraniliprole at the ratio of chlorantraniliprole LC50 plus sesame oil 2.5 per cent on fall armyworm under laboratory conditions.