Biosynthesis of green silver nanoparticles using root and leaf extracts of Petiveria alliacea and utilization as nano-insecticides on ant (Pachycondyla chinensis)

Ant infestation is a serious concern among the people in both urban and rural areas; hence, control becomes necessary. Nano-insecticides have been described as one of the alternatives to conventional chemicals due to their environmentally friendly nature. Silver nanoparticles were biosynthesized using Petiveria alliacea leaf (PaL-AgNPs) and Petiveria alliacea root (PaR-AgNPs) against a species of ants (Pachycondyla chinensis) at four concentrations (25%, 50%, 75% and 100% v/v), with different modes of applications (contact, fumigant and feeding deterrent). Synthetic insecticides (Dichlorvos) and control were included in the treatments for comparison. The treatments were arranged in a Complete Randomized Design with 3 replications. Silver nitrate was used in the biosynthesis of AgNPs by P. alliacea leaf (PaL-AgNPs) and root (PaR-AgNPs) with maximal absorbance ranging from 426-442 nm. The results clearly showed that nano P. alliacea leaf and root exhibited insecticidal potential against the studied insect when compared with untreated ants. However, PaR-AgNPs had significantly higher efficacy than PaL-AgNPs in the studied insect. None of the nano-insecticide formulations was as effective as dichlorvos at the earlier stage of application. However, the mode of application and concentrations applied determined the toxicity of the tested nano-insecticides. Therefore, green silver nanoparticles derived from P. alliacea leaf and root extracts can be used to control ant infestations.