CHEMICAL COMPOSITION AND INSECTICIDAL EFFICACY OF VITEX NEGUNDO L. ESSENTIAL OIL AGAINST FALL ARMYWORM, SPODOPTERA FRUGIPERDA (J. E. SMITH)

Abstract

The fall armyworm, Spodoptera frugiperda, is a key pest ofmaize crops in tropical and subtropical regions and has developed resistanceagainst synthetic pesticides and Bacillus thuringiensis toxins. Thus,the experiments were designed to evaluate the chemical analysis andinsecticidal efficacy of Vitex negundo against S. frugiperda.Chemical analysis of V. negundo essential oil revealed a total of 36compounds, and the oil contained more monoterpenes (68.16%) than sesquiterpenes(22.21%) and diterpenes (13.56%). For the ovicidal and insecticidal activities,the essential oil was found to be most effective, with a median lethalconcentration (LC50) value of 51.31 µL/mL and 0.29 L/larvae, respectively.Larval antifeedant and growth inhibitory activity of essential oil werepositively correlated (R2 = 0.9645) and (R2 = 0.9727) with oil concentrations,respectively. Therefore, the V. negundo essential oil can be used forthe development of bioinsecticides to control S. frugiperda, a highlyinvasive and polyphagous pest, which will replace chemical pesticides.