Nano-insecticides against the black cutworm Agrotis ipsilon (Lepidoptera: Noctuidae): Toxicity, development, enzyme activity, and DNA mutagenicity.

Mona Awad,Abdel Wahab M Mahmoud,Engy I Osman,Wael H Elmenofy,Moataz A M Moustafa,El-Desoky S Ibrahim,Mohamed A M Atia,Ramzi Mansour

doi:10.1371/journal.pone.0254285

Abstract

Frequent applications of synthetic insecticides might cause environmental pollution due to the high residue. In addition, increasing insecticide resistance in many insect pests requires novel pest control methods. Nanotechnology could be a promising field of modern agriculture, and is receiving considerable attention in the development of novel nano-agrochemicals, such as nanoinsectticides and nanofertilizers. This study assessed the effects of the lethal and sublethal concentrations of chlorantraniliprole, thiocyclam, and their nano-forms on the development, reproductive activity, oxidative stress enzyme activity, and DNA changes in the black cutworm, Agrotis ipsilon, at the molecular level. The results revealed that A. ipsilon larvae were more susceptible to the nano-forms than the regular forms of both nano chlorine and sulfur within the chlorantraniliprole and thiocyclam insecticides, respectively, with higher toxicities than the regular forms (ca. 3.86, and ca.2.06-fold, respectively). Significant differences in biological parameters, including developmental time and reproductive activity (fecundity and hatchability percent) were also observed. Correspondingly, increases in oxidative stress enzyme activities were observed, as were mutagenic effects on the genomic DNA of A. ipsilon after application of the LC50 of the nano-forms of both insecticides compared to the control. These promising results could represent a crucial step toward developing efficient nanoinsecticides for sustainable control of A. ipsilon.

Highlights

The black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae) is a major insect pest that can destroy many important crops worldwide [1]
A single drop of the nanoparticle solution was spread onto a carbon-coated copper grid, and was posteriorly dried at room temperature for transmission electron microscope (TEM) analysis
The results showed elongation of the larval developmental period under all LC50 treatments, while pupal duration was significantly increased in larvae exposed to regular form of both insecticides

Summary

Introduction

The black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae) is a major insect pest that can destroy many important crops worldwide [1]. Effects of chlorantraniliprole and thiocyclam and their nano-form on Agrotis ipsilon many crop species, vegetables, and weeds [2]. Chemical insecticides have been used to prevent crop loss by A. ipsilon [4]. Nanotechnology could provide new methods and agricultural products to counteract the fears related to the potential unwanted environmental impact of chemical insecticides through increased exposure and toxicity in non-target organisms [5]. Nano-pesticides have several advantages, including increased potency and durability, and a reduced amount of active ingredients [9]. They are considered to be a promising solution for the reduction of the environmental footprint left by chemical pesticides [7]. The increasing interest in the use of nano-pesticides raises questions about their fate, toxicity, and biodegradation [10], as well as how to assess the environmental risk of these materials

Methods

Results

Conclusion