Comparative Insecticidal Activity of Three Forms of Silica Nanoparticles on some Main Stored Product Insects

Abstract

The control of stored grain pests requires effective materials that are save for humans and environment, low cost, available and easy to obtain and do not need trained labor. Therefore, the current study suggested testing three silica forms in the form of nanoparticles, these were Aerosil 200, chemical and bio-silica for controlling Callosobrochus maculatus F. (Col., Bruchidae), Rhythopertha dominica fab, and Tribolium confusum (Jacquelin du Val). The obtained results showed that the percent mortality increased with the increasing of concentration and exposure period. Moreover, all the tested materials of nanoparticles had detrimental induction on mortality and offspring of the three tested insects. In addition the adults of C.maculatus were more susceptible followed by R.dominica and T.confusum with the three tested materials at the all concentrations used. Data obtained revealed that the activity of chemical silica had the first rank followed by Aerosil 200 and bio-silica where the LC50 of chemical silica ranged between 0.14-1.54 one day posttreatment with significant distinction compared to Aerosil 200 (0.15-2.65) and bio-silica (2.43-7.35)g/kg grain. The findings obtained showed that the three forms of silica had deterrent action on the all tested immature stages at the all levels of concentrations. Also results clarified the egg stage was the most susceptible compared to larvae and pupae ones. The all treatments reduced the emerged adults and the losses of grain weight. Consequently the present study explained that the three used forms of silica are promising materials for controlling the tested insects as safe alternatives to the synthetic insecticides.