Nanotechnology is increasingly being used in areas of pesticide production and pest management. This study reports the isolation and virulence of a new Metarhizium anisopliae isolate SM036, along with the synthesis and characterization of M. anisopliae-chitosan nanoparticles followed by studies on the efficacy of nanoparticles against Plutella xylostella. The newly identified strain proved pathogenic to P. xylostella under laboratory conditions. The characterization of M. anisopliae-chitosan nanoparticles through different analytical techniques showed the successful synthesis of nanoparticles. SEM and HRTEM images confirmed the synthesis of spherical-shaped nanoparticles; X-ray diffractogram showed strong peaks between 2θ values of 16-30°; and atomic force microscopy (AFM) analysis revealed a particle size of 75.83 nm for M. anisopliae-chitosan nanoparticles, respectively. The bioassay studies demonstrated that different concentrations of M. anisopliae-chitosan nanoparticles were highly effective against second instar P. xylostella under laboratory and semi-field conditions. These findings suggest that M. anisopliae-chitosan nanoparticles can potentially be used in biorational P. xylostella management programs.
Keywords: Metarhizium anisopliae; Plutella xylostella; biopesticides; nano-formulation.