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 × 105
to 10 × 109
conidia ml−
1. However, mortality by M.
anisopliae KACC40029 reached maximally 60% at the dose of 10 × 109
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.