Chemical Composition and Pesticidal Activities Against Three Vector Mosquito Species of <i>Zanthoxylum armatum</i> DC. Essential Oils

In this study, we investigated the extraction yield and chemical composition of essential oils from the fruit, leaf, and twig of Zanthoxylum armatum from Vietnam. The fruit essential oil (FEO) with high content, representing a chemotype, was evaluated for pesticidal activities against three mosquito species Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus, according to the WHO guidelines with modifications. The results showed that the major constituents of FEO were limonene (30.50%), sabinene (15.16%), terpinen-4-ol (13.05%), and γ-terpinene (7.49%). The major constituents of leaf essential oil (LEO) were sabinene (20%), 1,8-cineole (16.97%), limonene (12.32%), and 2-undecanone (9.17%). The twig essential oil (TEO) was rich in ketones (73.84%), with the main constituents being 2-undecanone (47.33%) and 2-tridecanone (26.14%). FEO exhibited potential pesticidal activities: larvicidal activities with 24-h LC₅₀ values ranging from 21.55 to 29.53 µg/mL inhibited the biting of A. aegypti adults with a protection time of 176.5 ± 40.20 min, and exhibited potent adulticidal activities against A. aegypti. In addition, FEO did not exhibit cytotoxicity against the normal Vero cell line. This study contributes an evidence base to support the future development and use of FEO as a promising biopesticide agent for the control of disease-transmitting mosquito species and altering synthetic pesticides.