Effect of silver nanoparticles synthesized by Lecanicillium lecanii and their combinations with insecticides (Sivanto and Deltamethrin) on larvae and adults of Tribolium confusum Duv. (Tenebrionidae : Coleoptera)

Abstract

This research focused on developing a nanopesticide derived from silver nanoparticles (AgNPs) synthesized through the metabolic activities of the fungus Lecanicillium lecanii Gams & Zare 2001). The study aimed to assess its efficacy against the flour beetle Tribolium confusum and explore its synergistic effects with two chemical pesticides, Sivanto 20% and deltamethrin 2.5%. Biotinylated AgNPs were successfully produced using the biomass of the fungus L. lecanii. Characterization of silver nanoparticles was achieved through the observable color change of silver nitrate solution (AgNO₃) from a clear or watery state to red, brown, or dark red, confirmed by UVV is spectroscopy, with the highest absorption peak at 420 nm, indicative of silver element absorption. Transmission electron microscope images illustrated that the biologically prepared AgNPs with L. lecanii exhibited spherical shapes with sizes ranging from 12 to 40 nanometers. Various concentrations of nanopesticide, Sivanto, and deltamethrin were tested for the treatment of grains. A concentration of 1 ml/L of deltamethrin showed superior performance, with the mortality ratio increasing with prolonged exposure. Both Sivanto and deltamethrin (0.5 ml/L and 0.4 ml/L) caused 100% mortality, followed by the nanopesticide (30% concentration), reaching a corrected mortality rate of 39.3% against adults of T. confusum. In the larval experiment, the mortality rate was high when applying AgNPs at a concentration of 100%, comparable to Sivanto 0.5 ml/L under similar conditions. Deltamethrin exhibited complete mortality at a 1 ml/L concentration. [ Keywords: Silver Nanoparticles, Lecanicillium lecanii, Tribolium confusum