Abstract
Helicoverpa armigera Hübner, 1808 (Noctuidae; Lepidoptera) is one of the major pest problems causing production constraints in both conventional and organic agricultural systems. Chemical and semichemical, along with biotechnological approaches, like the sterile insect technique, are used to manage pest populations. However, these methods raise environmental concerns. Therefore, the current study was undertaken to assess the biocontrol potential of the entomopathogenic fungal strains Beauveria bassiana, Metarhizium anisopliae, Akanthomyces lecanii, and Purpureocillium lilacinus against H. armigera. These strains, identified through morphological and molecular techniques, were evaluated for their effectiveness in controlling H. armigera. A total of eight fungal strains were identified as entomopathogens, including B. bassiana (Bb01, Bb02, Bb03, and Bb04), Purpureocillium lilacinus (Pl01, Pl02), M. anisopliae (Ma01), and A. lecanii (Vl01). The plate pathogenicity assay revealed that B. bassiana (Bb04) inflicted the highest mortality to H. armigera among all the entomopathogenic fungi studied. B. bassiana (Bb04) was selected for further studies based on its pathogenicity. BLAST analysis revealed a high similarity (99%–100%) between the internal transcribed spacer regions of the studied isolates. The total dry weight of mycelia was significantly higher than the control for 1% starch concentrated medium, followed by 1% sucrose, 1% dextrose, and 1% lactose, respectively. The results confirmed that the use of B. bassiana (Bb04) was an eco-friendly and sustainable approach that could replace chemical insecticides.