Nanoformulation of imidacloprid insecticide with biocompatible materials and its ecological and physiological effects on wheat green aphid, Schizaphis graminum Rondani

Nanoformulation of imidacloprid was prepared using the biocompatible polymer of polyethylene glycol (PEG). TEM image showed that the spherical nanoparticles were 50–150 nm. The lethal concntrationof 30 percent (LC₃₀) and 50 percent (LC₅₀) of the insecticide and its nanoformulation studied on adult female aphids were 21.46 and 58.56 mg a.i./L for pure insecticide, and 3.79 and 4.94 mg a.i./L for nanoformulated insecticide, respectively. The results of the sublethal effect test (LC₃₀) of this insecticide showed that nymphal developmental in nanoimidacloprid (5.55 days) was higher than control (4.22 days). The results showed that the insecticide treatments significantly reduced the demographic characteristics of Schizaphis graminum. The intrinsic rates of increase (r) values of aphids in control, insecticide treatment and its nanoformulation were 0.421, 0.315 and 0.29, respectively. The results of evaluating the effect of the studied insecticide on the specific activity of beta-esterase and glutathione S-transferase showed that there was no significant difference in the activity of this enzymes between the control and the insecticide treatment and its nanoformulation. Based on the obtained results, it can be concluded that after conducting additional tests, the insecticide nanoformulation can be used due to its effectiveness in lower concentrations in the management of sucking pests such as aphids.