Characterization and biological activity of two new entomopathogenic Beauveria bassiana strains isolated from Hyphantria cunea larvae in Turkey

Abstract

In this study, two fungal strains (HC-Z1 and HC-Z2) from Hyphantria cunea (fall webworm) larvae were evaluated for their potential as biocontrol agents against the H. cunea larvae. Based on morphological and molecular (ITS1-5.8S-ITS2 region) characterization, the strains were identified as Beauveria bassiana (HC-Z1: OP415530 and HC-Z2: OP415531). To determine the biological activities of the two fungal strains, a concentration-response assay (1 × 104-8 conidia/ml) was performed against third stage H. cunea larvae. In addition, two B. bassiana strains were tested on five (1-5) larval stages at 1 × 107 conidia/ml concentration. Both isolates produced mortalities over 96% within 7 days for the first larval stage of H. cunea. The LC50 and LT50 of HC-Z1 and HC-Z2 strains against third instar H. cunea larvae were calculated as 0.6 × 104 and 1.2 × 104 conidia/ml, respectively. LT50 values were obtained in 2.82 and 3.44 days for HC-Z1 and HC-Z2 isolates, respectively. As a result, it can be concluded that HC-Z1 and HC-Z2 strains can potentially be used as biological control agents against H. cunea.