Larvicidal and Antifeedant Effects of Copper Nano-Pesticides against Spodoptera frugiperda (J.E. Smith) and Its Immunological Response

Abstract

This study aimed to synthesize and evaluate the efficacy of CuO NPs (copper oxide nanoparticles) with varying test concentrations (10–500 ppm) against larvicidal, antifeedant, immunological, and enzymatic activities against larvae of S. frugiperda at 24 h of treatment. Copper nanoparticles were characterized by using a scanning electron microscope (SEM) and energy dispersive X-ray (EDaX) analysis. The EDaX analysis results clearly show that the synthesized copper nanoparticles contain copper as the main element, and the SEM analysis results show nanoparticle sizes ranging from 29 to 45 nm. The CuO NPs showed remarkable larvicidal activity (97%, 94%, and 81% were observed on the 3rd, 4th, and 5th instar larvae, respectively). The CuO NPs produced high antifeedant activity (98.25%, 98.01%, and 98.42%), which was observed on the 3rd, 4th, and 5th instar larvae, respectively. CuO NPs treatment significantly reduced larval hemocyte levels 24 h after treatment; hemocyte counts and sizes changed in the CuO NPs treatment compared to the control. After 24 h of treatment with CuO NPs, the larval acetylcholinesterase enzyme levels decreased with dose-dependent activity. The present findings conclude that CuO NPs cause remarkable larvicidal antifeedant activity and that CuO NPs are effective, pollution-free green nano-insecticides against S. frugiperda.

Biosynthesis of Copper Nanoparticles from Acacia cornigera and Annona purpurea and Their Insecticidal Effect against Tribolium castaneum

“…Recent reports showed that copper can affect the development of insects (e.g., dragonfly larvae) as a result of inhibition of the activity of acetylcholinesterase [26]. On the other hand, recent studies reported that CuNPs have attracted a great deal of attention from all over the world due to their insecticide activity [27]. Rahman et al [28] mention that copper oxide nanoparticles demonstrated high larvicidal in Spodoptera frugiperda (J.E.…”

Insecticidal activity of Silica, Zinc and Copper nanoparticles against the German cockroach, Blatella germanica (L.) (Dictyoptera: Blattellidae)

“…Pittarate et al (2021) and Eskin & Nurullahoğlu (2022) also concluded that ZnO-NPs have toxic effects on Spodoptera frugiperda and Galleria mellonella. Other authors reported the toxic effects of CuO-NPs against different mosquito species (Vivekanandhan et al 2021a, b) and Spodoptera frugiperda (Rahman et al, 2022).…”

Biocontrol efficacy of cajeput oil against Anopheles stephensi L. mosquito and its effect on non-target species

“…Chemical constituents derived from microbes, plant crude extract and essential oils (EOs) are promising for reducing mosquito populations (Vivekanandhan et al, 2018a;Vivekanandhan et al, 2018b;Vivekanandhan et al, 2018c;Balumahendhiran et al, 2019;Logeswaran et al, 2019;Vivekanandhan et al, 2020a;Vivekanandhan et al, 2020b;Perumal et al, 2023a;Perumal et al, 2023b;Perumal et al, 2023c). In the case of insecticide-resistant mosquitoes, EOs can act as biorational alternatives or synergist additives to existing insecticides.…”

“…Insect acetylcholinesterase (AChE) is an important enzyme in the nervous system that facilitates nerve signal transmission by degrading acetylcholine. Pesticides frequently inhibit AChE activity and cause neurotoxic effects in insects (Vivekanandhan et al, 2022;Perumal et al, 2023a;Perumal et al, 2023b;Perumal et al, 2023c). Understanding AChE offers insights into insecticide mechanisms and aids in the development of pest control strategies.…”