Entomopathogenic Fungi-Mediated AgNPs: Synthesis and Insecticidal Effect against Plutella xylostella (Lepidoptera: Plutellidae)

Abstract

The insect Plutella xylostella is known worldwide to cause severe damage to brassica plantations because of its resistance against several groups of chemicals and pesticides. Efforts have been conducted to overcome the barrier of P. xylostella genetic resistance. Because of their easy production and effective insecticidal activity against different insect orders, silver nanoparticles are proposed as an alternative for agricultural pest control. The use of entomopathogenic fungi for nanoparticle production may offer additional advantages since fungal biomolecules may synergistically improve the nanoparticle’s effectiveness. The present study aimed to synthesize silver nanoparticles using aqueous extracts of Beauveria bassiana, Metarhizium anisopliae, and Isaria fumosorosea isolates and to evaluate their insecticidal activity against P. xylostella, as innovative nano-ecofriendly pest control. The produced silver nanoparticles were evaluated by measuring the UV–vis spectrum and the mean particle size by dynamic light scattering (DLS). I. fumosorosea aqueous extract with 3-mM silver nitrate solution showed the most promising results (86-nm mean diameter and 0.37 of polydispersity). Scanning electron microscopy showed spherical nanoparticles and Fourier-Transform Infrared Spectroscopy revealed the presence of amine and amide groups, possibly responsible for nanoparticles’ reduction and stabilization. The CL50 value of 0.691 mg mL−1 was determined at 72-h for the second-instar larvae of the P. xylostella, promoting a 78% of cumulative mortality rate after the entire larval stage. From our results, the synthesis of silver nanoparticles mediated by entomopathogenic fungi was successful in obtaining an efficient product for insect pest control. The I. fumosorosea was the most suitable isolate for the synthesis of silver nanoparticles contributing to the development of a green nanoproduct and the potential control of P. xylostella.

Termiticidal Effects and Morpho-Histological Alterations in the Subterranean Termite (Odontotermes formosanus) Induced by Biosynthesized Zinc Oxide, Titanium Dioxide, and Chitosan Nanoparticles

“…Asghar et al [ 57 ] investigated the biological synthesis of Ag and ZnO nanoparticles against Helicoverpa armigera. Santos et al [ 58 ] documented the insecticidal effects of mycosynthesized AgNPs against Plutella xylostella ( P. xylostella ). The study involved feeding cabbage leaves that had been dipped in AgNPs to the insects, demonstrating the nanoparticles’ pesticidal properties.…”

The impact of carbon NPs on the accumulation of storage proteins and the generation advancement of the polyphagous insect pest tobacco cutworm Spodoptera litura (Fabricius)

“…[12][13][14][15] AgNPs and AuNPs prepared from various plant sources reduced the larval weight and caused mortality in the larva and pupa of Helicoverpa armigera (Hübner) and Plutella xylostella (Linnaeus). [16][17][18][19][20][21][22] SiNPs generated from various plant sources caused 85-100% mortality of H. armigera, S. litura, and P. xylostella larvae by disruption of the cuticle, resulting in dehydration along with spiracle and tracheal blockage. [23][24][25][26] Carbon nanoparticles in the form of fly ash have been used to control the lepidopteran pest.…”