Research Information System
Crop Protection, vol.204, 2026 (SCI-Expanded, Scopus)
Chemical pesticides remain significant risks to human health and environmental sustainability, necessitating safer alternatives. This study systematically investigates the potential of native Beauveria bassiana isolates from seven geographical regions of Türkiye as biological control agents against Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), a major potato pest. A total of 180 soil samples collected from seven geographical regions of Türkiye yielded 71 entomopathogenic fungal isolates morphologically identified as Beauveria spp. The Galleria baiting method recovered 84.5% of isolates, while soil dilution yielded 15.5%. From the 71 morphologically identified isolates, 31 representative isolates from diverse locations were selected for molecular confirmation. Molecular analysis using ITS and TEF-1α regions confirmed all selected isolates as B. bassiana, while BLOC and RPB2 amplification success varied among isolates. Five natives Beauveria bassiana isolates (Ay1, Bey, Artv, Lul1, and Den2) representing geographical regions and ecological habitats were selected based on geographical diversity for pathogenicity evaluation alongside the standard B. bassiana strain KVL03129. Bioassays comparing three application methods (spraying, leaf dipping, and larvae dipping) demonstrated that spraying achieved the highest efficacy. Concentration-dependent pathogenicity assessment using the spraying method at 1 × 107, 1 × 106, and 1 × 105 conidia/mL against L. decemlineata 4th instar larvae revealed significant differences among strains. The standard strain KVL03129 achieved a median lethal time (LT50) of 3.6 days, while the native B. bassiana Artv isolate achieved an LT50 of 5.1 days at 1 × 107 conidia/mL, demonstrating the highest virulence among native strains. These findings demonstrate that native B. bassiana isolates represent promising candidates for biocontrol development against L. decemlineata.