Molecular docking and mechanistic insights into the insecticidal potential of Cinnamomum verum and Thymus vulgaris essential oils against Thrips parvispinus

Thrips parvispinus Karny, is one of the most destructive pests of chilli, causing direct feeding damage to flowers, leaves, and fruits, collectively cause substantial yield and market value losses, with outbreaks resulting in 80-100% crop loss in recent years. Farmers heavily rely on synthetic insecticides for management, but their indiscriminate use has led to pest resurgence, resistance, residue accumulation, and environmental and human health hazards. These challenges necessitate eco-friendly alternatives such as botanical pesticides. Essential oils (EOs), volatile secondary metabolites from plants, are promising candidates due to their multiple modes of action, rapid degradation, low mammalian toxicity, and compatibility with Integrated Pest Management (IPM) programs. In this study, ten EOs-cardamom, cinnamon, cinnamon bark, eucalyptus, palmarosa, thyme, marigold, ylang ylang, geranium, and vetiver-were screened for insecticidal activity against T. parvispinus . The results revealed that cinnamon bark ( Cinnamomum verum ) and thyme ( Thymus vulgaris ) exhibiting the highest efficacy against T. parvispinus . Gas Chromatography-Mass Spectrometry (GC-MS) analyses identified bioactive compounds including thymol, α-pinene, para-cymene, geraniol, and eucalyptol as major constituents. Enzyme inhibition assays demonstrated that EOs modulated detoxification enzymes (esterases, glutathione S-transferase) and acetylcholinesterase (AChE), corroborating their neurotoxic action on target pests. In-silico docking further supported these findings, with EO-derived ligands showing strong binding affinity toward AChE of T. parvispinus . Overall, the results underscore the potential of cinnamon bark and thyme essential oils as effective alternatives to synthetic pesticides. This study thus advances the integration of essential oils into IPM strategies for long-term crop protection and food safety.