Isolation, molecular characterization of indigenous Beauveria bassiana isolate, using ITS-5.8 s rDNA region and its efficacy against the greatest wax moth, Galleria mellonella L. (Lepidoptera: Pyralidae) as a model insect

Abstract

Abstract The entomopathogenic fungi (EPF), as a biological control agent, can provide an alternative option for high-risk insecticides. Beauveria bassiana is one of the most potential EPF of pest control all over the world. The EPF isolate Y-F_ITS1 was isolated from Egyptian fauna on Beauveria-specific selective medium (BS medium). Molecular screening of the B. bassiana isolate, using PCR amplification with B. bassiana-specific primers and nucleotide sequence analysis of the internal transcribed spacer (ITS) region, confirmed the isolate as B. bassiana (accession no. [MK773644.1]). Efficacy of the isolate Y-F_ITS1 was examined against fourth instar larvae of Galleria mellonella L. as a model insect using concentrations from 104 to 107 spores ml−1 in a contact toxicity assay under laboratory conditions. The pathogenicity experiment showed that all the tested concentrations caused mortalities ranged from 75 to 98.33%, within 5 days posttreatment with cumulative mortalities, reached 100%, before 7 days with typical symptoms of infection and sporulation. Further investigations are needed to prove its efficacy against different economic pests as a credible candidate of integrated pest management (IPM) program.

Keywords

• Biological control
• Entomopathogenic fungi
• Beauveria bassiana
• ITS
• Galleria mellonella