Toxicity and Growth-Disruptive Effects of Silica, Zinc and Aluminum Oxide Nanoparticles on Spiny Bollworm, Earias insulana

摘要

Background and Objective: Nanoparticles (NPs) are the most efficient technique of pest control without disturbing the potentialenvironmental balance. This study was carried out to compare the toxicity effects of Silica, Zinc and Aluminum oxide NPs on growth,development, malformation and chitin formation parameters of Earias insulana. Materials and Methods: Newly hatched larvae fedon the treated diet for 48 hrs following by the untreated one until pupation. The toxicity impacts of LC50values for each tested NPswere calculated. The fourth instar larvae prepared for scanning electron microscopy and also for defining the chitin formation.Results: The ZnONPs was the highest toxicity, followed by SiO2 and Al2O3 NPs. The treatment with ZnONPs has scored an extremereduction in the weight compared to other tested NPs. The growth rate inhibition decreased gradually until the fourth instars and then increased slightly in the prepupae and pupae in favor of ZnONPs, while Al2O3 NPs was the least effective one. Under-tested NPs, theincrease in the larval and pupal periods led to a sharp reduction in the developmental rate and a significant increase in larval deformations.Besides, the least chitin formation ratio was registered in response to ZnONPs. By using electron microscopy, distinct differences wereobserved in the distribution of NPs on the cuticle surface of the fourth-instars body parts. Conclusion: This study recommends thepractical use of ZnO, SiO2 and Al2O3 NPs, respectively, in pest control programs of E. insulana as safe alternative materials.