Abstract
Fall armyworm, Spodoptera frugiperda is an invasive polyphagous pest and has annually invaded Korea since it was first reported in 2019. This pest has already acquired resistance to synthetic chemical pesticides. To minimize the damage caused by S. frugiperda, alternative control methods with different mode of action should be developed. In this study, we assessed the virulence of native entomopathogenic fungi against S. frugiperda and investigated application methods to effectively control the target insect. We obtained 93 fungal isolates and assayed their pathogenicity against second instar larvae. Of the 93 isolates, 34 isolates caused high mortality. Based on their virulence, conidial productivity, and thermotolerance, ten isolates were selected for quantitative bioassays. In the bioassays using leaf dipping, all isolate treatments showed high virulence against second instar larvae, but only two isolates, Beauveria bassiana JEF-492 and Sf83 caused 93.3% and 86.7% mortality against fourth instar larvae, respectively. Given the soil-dwelling pupal stage, drenching the soil with Metarhizium anisopliae JEF-157 and B. bassiana JEF-492 from the selected isolates reduced the survival rate of pupae by up to 80% under laboratory conditions. The M. anisopliae JEF-157 and B. bassiana JEF-492 cultured on barley and rice showed high conidial productivity and thermotolerance. Our results show that soil application of M. anisopliae JEF-157 and B. bassiana JEF-492 targeting pupal stage could be effectively combined with the spray on the leaf-dwelling larval stage when the isolates encounter unfavorable abiotic stress on the leaves.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.