Biologicalstudies on the efficacy of two native fungal pathogens against fall armyworm <i>Spodoptera frugiperda</i> (Lepidoptera: Noctuidae)

The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), a notorious and adaptable pest, has inflicted substantial crop yield losses globally. This research investigated the potential of two native entomopathogenic fungi, Beauveria bassiana and Purpureocillium lilacinum, Isolations were conducted at the biopesticide production unit at the Plant Protection Research Institute as biocontrol agents against S. frugiperda larvae. In laboratory trials, larvae were exposed to five different concentrations of fungal spores, ranging from 1×10⁵ to 1×10⁹ spores/ml. Researchers then meticulously tracked mortality rates, larval development time, pupation rates, adult longevity, and fecundity. The study revealed a clear, dose-dependent relationship between fungal concentration and larval mortality. B. bassiana emerged as the most potent isolate, achieving an impressive 76.5% mortality within 6.1 days at the highest concentration. Both fungal isolations also significantly impacted other key life-cycle parameters, reducing larval development time, pupation rates, adult longevity, and fecundity. These promising results suggest that these entomopathogenic fungi hold considerable potential as effective biocontrol agents in the fight against S. frugiperda. Future research will focus on optimizing application strategies for these fungal biocontrol agents and rigorously evaluating their efficacy under real-world field conditions.