Phytochemical Composition and Bio‐Efficacy of Agro‐Waste Plant Extracts and Their Potential as Bioinsecticides Against Culex pipiens Mosquitoes

ABSTRACT

This study assessed the larvicidal activity of methanol and hexane fruit peel extracts from Hylocereus polyrhizus (red dragon fruit), Citrus sinensis (sweet orange), Punica granatum (pomegranate), Annona cherimola (cherimoya), and Physalis peruviana (groundcherry) against third‐instar larvae of Culex pipiens , following WHO bioassay guidelines. Larval mortality was recorded at 24 and 48 h, and LC ₅₀ , LC ₉₀ , and LC ₉₅ values were calculated. Methanol extracts demonstrated greater larvicidal activity compared with hexane extracts. The most effective plants were H. polyrhizus , C. sinensis , and P. granatum . Based on 48‐h LC ₅₀ values, methanol extract toxicity followed the order: H. polyrhizus (157.73 ppm) <  C. sinensis (180.22 ppm) <  P. granatum (190.38 ppm) <  A. cherimola (249.98 ppm) <  P. peruviana (507.68 ppm). For hexane extracts, the ranking was H. polyrhizus (176.57 ppm) <  C. sinensis (220.36 ppm) <  P. granatum (252.63 ppm) <  A. cherimola (307.69 ppm) <  P. peruviana (651.06 ppm). GC/MS analysis of the five n ‐hexane extracts identified 57 compounds, mainly alkanes, alkenes, aldehydes, esters, ketones, triterpenoids, and fatty acid esters. In Physalis , fatty acid esters were predominant, followed by fatty acids and related compounds. UPLC/MS analysis of methanol extracts tentatively identified 16, 23, 21, 5, and 27 metabolites in Annona , Citrus , Hylocereus , Punica , and Physalis , respectively. Overall, methanol peel extracts, particularly from H. polyrhizus , C. sinensis , and P. granatum , exhibited strong larvicidal activity against Cx. pipiens , highlighting their potential as eco‐friendly alternatives for mosquito control.