Genetic expressions and evaluation of insecticidal activity of some essential oil and methomyl lannate 90% against Spodoptera frugiperda

Fall armyworm (FAW) Spodoptera frugiperda is regarded as a major pest of various economic crops, their caterpillars are a highly destructive and have a wide host range. The application of traditional pesticides is the main strategies used for its control, that resulting to number of negative impacts of pesticides on the environment and development of pesticide resistance.

This study’s goal was to assess the insecticide potency of three essential oils [rosemary (Rosmarinus officinalis L.), lemongrass (Cymbopogon citratus) and Cinnamon (Cinnamomum zeylanicum)] and methomyl lannate 90% commercial insecticide to control S. frugiperda (fall armyworm) and their effects on expression of caspase-8 and inhibitor of apoptosis protein genes and expression of acetylcholinesterase (AChE) gene in fall armyworm (FAW).

The insecticidal activity against second larval instar of fall armyworm was evaluated with five concentrations (2.5%, 2%, 1.0%, 0.5% and 0.25%) for essential oil and four concentrations 0.4%, 0.2%, 0.15% and 0.05% for methomyl lannate 90%. The findings indicated that raising both essential oil concentrations and methomyl lannate 90% resulted in increased larval mortality at high concentration. The expression levels of Ache gene treated by low dose (0.3 µ/L) of methomyl lannate were increased (by 313%) significantly compared with the control but without significant differences.

The tested essential oils showed insecticidal activity against the second larval instar of S. frugiperda death as a result of treatment with the tested oils having an effect on the genes that the pest uses to express critical processes (genes of apoptosis).