Susceptibility of fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae) to natural products and entomopathogenic fungi

Synthetic insecticides have a direct adverse effect on the natural enemies and long-term residual effects causing serious environmental pollution as well. Public awareness of a clean environment increased the attention to developing alternative eco-friendly approaches. The objectives of this study are the detection of the effect of Beauveria bassiana , Metarhizium anisopliae , and natural products of plant-extract origin on the fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae) under laboratory conditions. The drench-bioassay results showed that mortality of larvae by B. bassiana KACC40224 increased from 10 to 80% as the dose was increased from 10 × 10 5 to 10 × 10 9 conidia ml −1 . However, mortality by M. anisopliae KACC40029 reached maximally 60% at the dose of 10 × 10 9 conidia ml −1 . All natural-extract products tested against the insect pest were effective, except lavender oil, which caused mortality to vary between 10 and 100%. Rosemary oil was found to be the most effective essential oil, showing 10% to 100% mortality indices at a concentration of 0.1 and 0.2% (v/v), respectively. S. frugiperda eggs tend to be more susceptible to entomopathogenic fungi rather than the larvae. The essential oils exhibited significant insecticidal properties against the larvae of S. frugiperda . This study could help in the development of potential biopesticides for the environment-friendly management of the fall armyworm S. frugiperda pest and emphasize the advantages of entomopathogenic fungi application.