Characterization of Native Entomopathogenic Nematode Isolates from Bilecik, Türkiye: Heat Tolerance, Dispersal, and Pathogenicity

This study aimed to evaluate the biological and ecological characteristics of entomopathogenic nematode isolates collected from soil samples in Bilecik, Türkiye, to assess their potential for use in biological pest control. The isolates were tested for their dispersal ability in olfactometers, pathogenicity against greater wax moth larvae, and tolerance to elevated temperatures. A commercial strain and a hybrid strain were included as references for comparison. The experiments revealed significant variability among the isolates. One local isolate exhibited strong dispersal capacity and heat tolerance, outperforming the reference strains in some parameters. Conversely, certain isolates showed lower levels of virulence, indicating limited pest control potential. Lethal dose assays demonstrated that pathogenicity varied substantially, with some local isolates matching or exceeding the performance of commercial strains under laboratory conditions. Mortality assessments across increasing temperature levels revealed that sensitivity to heat stress was not uniform and differed considerably among isolates. The findings confirm that biological performance is highly isolate-dependent and influenced by multiple interacting traits. While some local isolates showed promise in one or more evaluated traits, no single isolate combined superior performance in all parameters. Therefore, the results provide a valuable foundation for further characterization studies involving additional traits such as reproductive capacity, storage potential, and field efficacy. Overall, this study emphasizes the importance of locally adapted isolates in developing effective and environmentally sustainable pest management strategies. Selecting and improving such isolates may contribute to the broader adoption of biological control practices and reduce dependency on chemical pesticides.