LAUSR

Abstract Interest in botanical insecticides derived from plants has increased as a result of environmental concerns and insect resistance to chemical insecticides. In this study, we explored the insecticidal activity of Urginea maritima bulbs extract and its inhibitory effect on acetylcholinesterase enzyme system in the rice weevil Sitophilus oryzae (L.) (Coleoptera: Curculionidae). Phytochemical screening and HPLC-ESI/TOF-MS analysis revealed the presence of bioactive molecules with high insecticidal potential. Content of polyphenols (130.88 ± 0.44 mg GAE/g FW), flavonoids (50.81 ± 0.25 mg RE/g FW) as well as alkaloids (12.09 ± 0.16 mg AE/g FW) were high. HPLC-ESI/TOF-MS analysis results demonstrated that ferulic acid (124.19 μg/g FW), vanillic acid (75.84 μg/g FW) and 4-hydroxybenzoic acid (59.73 μg/g FW) were the major phenolic compounds of U. maritima bulbs extract. The toxic potential against the rice weevil using contact and repellent bioassays showed the highest insecticidal potential of U. maritima bulbs extract. The LD50, LC50 and RC50 values were 19.03 μg/insect, 2.35 μg/cm2 and 0.009 μg/cm2 for contact bioassay by topical application, contact bioassay by treated filter paper method and repellent bioassay, respectively. Furthermore, U. maritima bulbs extract inhibited acetylcholinesterase (AChE) activity and median inhibition concentration IC50 was evaluated to 66.08 μg/ml. The findings of the present investigation confirmed that Urginea maritima may be recommended as an eco-friendly alternative to synthetic insecticides.