محمدعلی میرحسینی

This research was conducted to evaluate the compatibility of the entomopathogenic fungus, Beauveria bassiana with silica nanoparticles (SNPs) against the saw-toothed grain beetle, Oryzaephilus surinamensis (L.) (Coleoptera, Silvanidae) and the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) under laboratory conditions. Three isolates of B. bassiana, including IRAN1395C, OZ1 and OZ2, were incorporated into wheat grains and assessed for their efficacy against the adult insects. All isolates were demonstrated significant insecticidal activity, with mortality rates ranging from 30.85 to 81.48 %. Notably, R. dominica adults exhibited greater susceptibility to the fungal isolates than O. surinamensis. Additionally, the toxicity of SNPs was evaluated on adult insects, revealing a considerably lower LC50 value for O. surinamensis adults (15.80 mg/kg) compared to R. dominica adults (533.77 mg/kg). The effect of SNPs at LC25 on mycelial growth and sporulation of the B. bassiana was also studied, showing that SNPs did not adversely affect fungal vegetative growth and sporulation, indicating compatibility with the tested isolates. Furthermore, the combined application of SNPs and fungi showed that the co-application of SNPs with either of the B. bassiana isolates had a synergistic effect against O. surinamensis adults, while an additive effect was observed for R. dominica adults. These findings suggest that SNPs have potential to be used as an effective co-formulant to enhance the effectiveness of entomopathogenic fungus B. bassiana against the tested storage beetles, offering a promising strategy for integrated pest management in stored product protection.