Molecular docking and chemical composition of commercial essential oils and their toxicity against Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae)

Plants' essential oils (EOs) market is expanding, and the commercialization of these products is for the most varied purposes, such as cosmetics, medicines, aromatization of environments, and phytotherapy. Terpenes and phenylpropanoids are present in the composition of EOs and are recognized for their insecticidal activities. Here, we determined the composition of six commercial EOs and verified if they had insecticidal activity against eggs and young larvae of Spodoptera frugiperda , a worldwide important insect pest. Toxicity was compared with neem oil, a natural insecticide. The six EOs had at least 96.66% of their constituents identified, with major compounds representing from 38.63–84.39% of the composition. In the egg bioassay, 78% of S. frugiperda eggs exposed to EOs became unviable, while neem oil made 42% of the eggs unviable. In general, the EOs efficiency decreased as the larvae aged and copaiba oil was as toxic as neem oil, demonstrating the potential for insect pest control. To support the biological findings at the molecular level, in silico molecular docking simulations were performed using the crystal structure of the S. frugiperda Scavenger Receptor-C MAM domain (PDB ID: 8YT7). Major EO compounds such as β-caryophyllene, eugenol, geraniol, 1,8-cineole, and terpinen-4-ol exhibited notable binding affinities and non-covalent interactions with the target protein, indicating potential receptor-mediated mechanisms involved in their insecticidal action.