Effective and eco-friendly botanical insecticidal agents against Spodoptera frugiperda (Noctuidae: Lepidoptera) using the essential oil of Stevia rebaudiana

Abstract

Using synthetic pesticides is the main strategy for controlling pests. However, these compounds have caused worry because of their harmful effects on health and their diminishing efficacy against pests that have developed resistance. Consequently, there is a growing interest in adopting more sustainable control methods. Stevia rebaudiana is a valuable medicinal plant used in the food industry for the production of steviol glycosides, a type of natural sweetener. An EO that could be useful for creating innovative insecticides may come from the industrially used plant biomass. In this study, gas chromatography-mass spectrometry (GC-MS) was used to analyse the chemical composition of S. rebaudiana leaves. Sesquiterpenes, or caryophyllene oxide (20.7 %), spathulenol (14.9 %), and (E)-nerolidol (8.0 %), and diterpenes, or phytol (9.2 %), made up the majority of the EO composition. The efficacy of the EO major constituents, namely Phytol, (E)-nerolidol, Spathulenol, and Caryophyllene oxide, was also tested against S. frugiperda. Phytol was the most effective LC₅₀ = 14.38 mg/L, followed by (E)-nerolidol LC₅₀ = 15.88 mg/L, Spathulenol LC₅₀ = 18.42 mg/L, and Caryophyllene oxide LC₅₀ = 23.41 mg/L. Furthermore, some of the biological and histological features of the extracts were also studied in a lab setting. Overall, Stevia rebaudiana (Bertoni) should be given more consideration in the development of environmentally safe and efficient pesticides.