Toxicity of Cymbopogon flexuosus essential oil and citral for Spodoptera frugiperda

Abstract

Fall armyworm (FAW) (Spodoptera frugiperda) is a polyphagous insect responsible for damage to several crops. Synthetic chemical insecticides and genetically modified plants are the most commonly used methods for FAW control. However, the selection of resistant populations has been reported in several studies, justifying the search for new molecules to be used in the control of S. frugiperda. The aim of the present study was to evaluate the toxicity of lemongrass (Cymbopogon flexuosus) essential oil (LEO) and its major component (citral) in relation to FAW. Additionally, the anticholinesterase activity of LEO and citral was evaluated using acetylcholinesterase (AChE) from Electrophorus electricus. The LEO was toxic to FAW when added to an artificial diet (LC50 = 1.35 mg mL-1) at the highest concentrations tested, and the median lethal time (LT50) was 18.85 h. Major components of LEO were identified by gas chromatography-mass spectrometry, and citral, the most abundant component, was used in FAW bioassays. The insecticidal activity of citral was statistically similar to that of LEO, demonstrating that citral was responsible for the insecticidal activity of LEO. Inhibition of AChE was measured, and the mean inhibitory concentration (IC50) values for LEO and citral were 650- and 405-fold higher, respectively, than that verified for the positive control (methomyl insecticide), suggesting selectivity for non-target organisms. Based on these results, citral and C. flexuosus have the potential to be applied in the development of new products for the control of S. frugiperda.

Insecticidal Activity of Lemongrass Essential Oil as an Eco-Friendly Agent against the Black Cutworm Agrotis ipsilon (Lepidoptera: Noctuidae)

“…C. citratus EO has a toxic effect on Spodoptera frugiperda, where the LC 50 was 1.35 mg/L, while the LC 50 was 1.042 mg/L after treating the larvae with citral from C. flexuosus [72]. Park et al [73] found that LC 50 of the EOs of C. aurantium fruits was 92.58 and 113.26 mg/L against Pochazia shantungensis nymphs and adults, respectively.…”

Inhibition of Glucosyltransferase Activity and Glucan Production as an Antibiofilm Mechanism of Lemongrass Essential Oil against Escherichia coli O157:H7

“…Previous evidence described the ability of citral and geraniol-like terpenes to traverse the bacterial membrane and interact with vital metabolic enzymes [13]. Previous studies also evidenced the potential of citral to inactivate several enzymes [14,15]. Therefore, the objective of this study was to explore the effect of C. citratus EO, citral, and geraniol on the glucans production, glucosyltransferase activity, and biofilm formation of E. coli O157:H7.…”

Essential Oils of New Lippia alba Genotypes Analyzed by Flow-Modulated Comprehensive Two-Dimensional Gas Chromatography (GC×GC) and Chemometric Analysis

“…Citral is an open chain monoterpenoid formed by the neral and geranial stereoisomers found in several medicinal plants and widely used as additives in foods, beverages, and cosmetics, due its intense lemon aroma and flavor [ 50 ]. A plethora of pharmacological properties have already been reported to citral, such as antibacterial [ 51 ], antifungal [ 52 ], insecticide [ 53 ], antioxidant [ 16 ], anticancer [ 54 ], anti-inflammatory [ 55 ], and anti-nociceptive [ 56 ] activities.…”