Advances in stored-product pests control: evaluation of the efficacy of myrrh essential oil on two Tenebrionidae species through a metabolomic approach

The tenebrionids Tenebrio molitor L. and Alphitobius diaperinus (Panzer) are significant stored-product insects worldwide. The present study investigates the insecticidal activity and underlies metabolic disruptions induced by Commiphora myrrha (T.Nees) Engl. essential oil (EO) against both species. Adults and larvae were exposed to EO-treated wheat at 500 and 1000 ppm, with mortality monitored over seven days. Commiphora myrrha EO demonstrated significant dose- and time-dependent toxicity, achieving up to 91.1 % mortality of A. diaperinus larvae and 86.7 % mortality of A. diaperinus adults and T. molitor larvae at 1000 ppm, outperforming the commercial insecticide pirimiphos-methyl, except from the T. molitor adults. Chemical characterization via GC-MS and HPLC-DAD identified furanosesquiterpenes—especially furanoeudesma-1,3-diene, curzerene, and lindestrene—as dominant constituents. EO exposure led to pronounced metabolic perturbations, particularly in larvae, affecting pathways related to sugar metabolism, neurotransmission, oxidative stress, and energy homeostasis. Debiased sparse partial correlation (DSPC) network analyses revealed fragmented and modular metabolic reorganization under EO treatment, contrasting with the more integrated disruptions induced by pirimiphos-methyl. These patterns suggest distinct biochemical responses to botanical versus synthetic insecticides. Overall, C. myrrha EO emerged as a potent candidate biopesticide with species- and stage-specific efficacy, supported by clear metabolomic signatures. These findings advance the understanding of plant-based pest control and highlight metabolomics as a powerful tool for unraveling insecticide mechanisms.