Biocontrol Potential of a New Beauveria varroae Strain Isolated from an Urban Ecosystem Against Two Species of Noctuidae Pests

Entomopathogenic fungi are among the most promising non-chemical alternatives for the control of many serious phytophagous insect pests, such as moth species. The present research investigates the use of the little-studied entomopathogenic fungus Beauveria varroae as a biocontrol agent against the notorious pests Helicoverpa armigera and Sesamia nonagrioides in laboratory conditions. Conidial suspensions of B. varroae were prepared at 103-104-105-106-107-108 conidia/mL to assess their insecticidal potential. In this study, we used 100 3rd-instar larvae for each concentration. During the lab bioassays, almost complete mortality of 35–96.6% was recorded for H. armigera larvae and 40–96.6% for S. nonagrioides larvae 10 days after exposure. The lethal effect of the entomopathogen was related to both dose and exposure time of the entomopathogen, with higher concentrations resulting in increased mortality. The survival effect of S. nonagrioides and H. armigera larvae was dependent on the hazard effect of the used dose and the exposure time. These findings indicate that B. varroae has potential as a biocontrol agent. Further research will elucidate this new isolate and optimize application methods in field conditions.