Bioactivity of some plant essential oils against fall armyworm (Spodoptera frugiperda JE Smith) (Lepidoptera: Noctuidae)

Abstract

Abstract Fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is a widely distributed and important pest of corn crops. However, the improper use of the conventional synthetic organophosphate and neonicotinoids pesticides to control S. frugiperda has led to resistant populations. Herein, the biological activities of some plant essential oils against S. frugiperda were determined to provide theoretical basis for the biological control of S. frugiperda. Our results showed that peppermint essential oil at 4.00% concentration showed the obvious ovicidal activity (96.00%) against S. frugiperda eggs, and lemon essential oil at 1.00% concentration had the greatest antifeedant activity (99.11%) against S. frugiperda larvae. Meanwhile, patchouli essential oil and patchouli essential oil at 4.00% concentration revealed remarkable fumigation and contact activities against S. frugiperda larvae at 96 h with the inhibition rates of 93.33% and 95.67%, respectively. In addition, the combination of patchouli essential oil and indoxacarb (in a ratio of 5:1) demonstrated the most effective synergistic effect (97.67%) on S. frugiperda larvae at 96 h. Moreover, the average dwell times of rosemary essential oil at 0.50% concentration against S. frugiperda larvae as well as citronella essential oil at 0.25% and 2.00% concentrations, patchouli essential oil at 1.00% and 4.00% concentrations, and lemon essential oil at 0.50% and 1.00% concentrations against both S. frugiperda male and female adults were all 0 s, indicating that some plant essential oils revealed excellent repellent activity against S. frugiperda. These findings could help to guide the development of new insecticides for the biological control of S. frugiperda.