Morphological and microstructural properties of silica (SiO 2 ) are essential factors that need to be considered during the experimental applications. In this report, SiO 2 nanoparticles (NPs) have been prepared at different concentrations from SiO 2 powder derived from olive stones and corncobs by an alkali leaching extraction method. Thermal treatment has been used to modify the morphological and microstructural properties of the extracted SiO 2 . X-ray diffraction (XRD) shows that the extracted amorphous SiO 2 has been transformed into a crystalline phase after the thermal treatment. Nitrogen adsorption-desorption measurements revealed signi cant reduction in both the speci c surface area (SABET) and the total pores volume (Vtotal) of the derived SiO 2 samples after the thermal treatment. The acquired thermal treatment properties of SiO 2 found to have high impacts on the in uence of the SiO 2 NPs on the survival and development of larvae and pupae of P. opercullela. SiO 2 NPs prepared from the crystalline silica samples exhibited less e ciency on suppressing potato tuber moth comparing to SiO 2 NPs of the amorphous silica powders. Varied effects on biological parameters including larvae mortality, pupae weight, larval and pupal development time, fecundity and fertility are also linked to the SiO 2 NPs source type and showed concentration depending manner effects. SiO 2 NPs are conditionally effective as an alternative pesticide against P. opercullela, based on their sources, mesoporous structures and concentrations.