Effect of silver and silica nanoparticles on the larvae of pink stem borer Sesamia cretica Lederer, 1857 (Lepidoptera: Noctuidae) and maize plants Zea mays Linneaus, 1753

This study was aimed to evaluate the toxicological and biological effects of three nanoparticles (silver, hydrophilic and hydrophobic silica) at four concentrations (100, 200, 400 and 800 ppm) against 1 instar larvae of Sesamia cretica Lederer, 1857 and its effects on some maize characters. Each concentration and control was repeated 4 times (10 larvae/replicate). Larvae were fed on treated stem maize and mortality rate was recorded. After treatment with LC50 values, the survival larvae were collected and the larval duration, pupal duration, pupal weight, pupation percentage and adult longevity were recorded. Seedling maize plants were sprayed with three concentrations (50, 100 and 200 ppm) at 4 categories (every 1, 3, 7 and 14 days) to detect the effect of nanoparticles on leaf area, extended height and leaf chlorophyll content. Results showed that hydrophilic silica nanoparticle was the most effective, followed by silver nanoparticle then hydrophobic silica nanoparticle with LC50 121.19, 405.71 and 416.82 ppm, respectively. All nanoparticles led to increase in larval durations, reduction of egg number per female and decrease of eggs hatchability rate. All nanoparticles caused positive effect on leaf area, extended height and chlorophyll content. These nanoparticles may be recommended to control S. cretica with positive effects on plant characters.