Abstract Tribolium castaneum and Sitophilus oryzae are listed among the most destructive pests of stored grains. Although synthetic insecticides and fumigants are commonly employed for their control, plant-based formulations offer safer, and eco-friendly alternatives. The aim of the current study was to explore the insecticidal potential of three aromatic plants against stored grain pests. Artemisia scoparia , Seriphidium brevifolium , and Salvia yangii were extracted using steam distillation and macerated in hexane and methanol, and their chemical compositions were investigated using gas chromatography-mass spectrometry. The insecticidal activity of plant essential oils (EOs) and solvent extracts was evaluated against laboratory-reared T. castaneum and S. oryzae using a fumigation bioassay. A. scoparia EO showed the highest insecticidal activity with LC 50 of 7.4 mg/L and 5.3 mg/L against T. castaneum and S. oryzae , respectively, after 12 h exposure. The LC 50 of S. brevifolium was 21.1 mg/L and 2.9 mg/L against T. castaneum and S. oryzae , respectively, after 12 h exposure. Compared to their respective EOs, plant solvent extracts exhibited lower bioactivity; however, the methanolic extract of S. brevifolium showed notable insecticidal activity against T. castaneum and S. oryzae . The major constituents found in A. scoparia EO were capillene (38.3%), γ-terpinene (19.3%), and β-myrcene (17.2%). The EO of S. brevifolium comprised camphor (31.6%), eucalyptol (29.3%), and thujone (9.9%). EOs and methanolic extracts of A. scoparia and S. brevifolium demonstrated the highest fumigant toxicity against T. castaneum and S. oryzae , highlighting their potential as botanical pest control agents to protect stored grains.
Ali et al. (Tue,) studied this question.