Molecular characterization and virulence of the entomopathogenic fungus Beauveria bassiana from Ostrinia nubilalis (Lepidoptera: Pyralidae)

Abstract

The European corn borer (Ostrinia nubilalis, Lepidoptera: Pyralidae) is one of the most important pest of maize and other crops, such as potato, green pepper, and winter wheat almost all over the world. In this study, we collected larvae from corn fields invaded by O. nubilalis during 2008-2010 in the Eastern Black Sea Region of Turkey and investigated fungal pathogens of this pest. As result of this investigation, one fungal species was isolated from O. nubilalis and it was characterized according to morphological and molecular characteristics. Based on these characteristics, the isolate was identified as Beauveria bassiana. Additionally, insecticidal activity of the isolate was determined on O. nubilalis larvae by testing different concentrations of conidia (1 × 104, 1 × 105, 1 × 106, 1 × 107 and 1 × 108 conidia ml-1). It caused 80% mortality within 13 days after inoculation of 1 × 108 conidia ml-1. Mycosis was calculated as 70% and LC50 value was also calculated as 4.8 × 105 conidia ml-1. These results indicate that Beauveria bassiana Ost3 seems to be a good candidate as biocontrol agent against O. nubilalis.