Investigation of Pesticidal Activities of Essential Oils Obtained from Vitex Species

Özet

Essential oils from renewable plant sources are important considerations for environmentally benign botanical pesticides. In this work, the leaf essential oils of four species of Vitex (Lamiaceae) have been collected from north-central Vietnam, analyzed by gas chromatographic techniques, and screened for mosquito larvicidal activity and molluscicidal activity. Vitex ajugifolia and V. pinnata essential oils were dominated by sesquiterpenoids (97.8% and 95.8%, respectively). In contrast, however, the essential oils of V. trifolia subsp. litoralis showed monoterpenoids to be dominant. The essential oils of V. trifolia subsp. trifolia also showed abundant monoterpenoids (38.4% and 68.0%), but also included (E)-β-caryophyllene (15.8 and 14.5%). Vitex pinnata essential oil showed excellent larvicidal activity against Aedes aegypti and Culex quinquefasciatus. Both V. trifolia litoralis and V. trifolia trifolia demonstrated notable molluscicidal activities against Gyraulus convexiusculus and Pomacea canaliculata. The research results suggest that essential oils of Vitex species might have potential to be used as natural pesticides.