Chemical Composition and Pesticidal Activity of Alpinia galanga (L.) Willd. Essential Oils in Vietnam

Mosquitoes are vectors of numerous pathogenic viruses and freshwater snails are intermediate hosts for several parasitic worms. There is a need for environmentally-benign botanical pesticides to augment or replace synthetic pesticides. In this research, essential oils from the leaves, stems, rhizomes, and roots of Alpinia galanga, an important Vietnamese medicinal plant, have been obtained by hydrodistillation and analyzed by gas chromatographic techniques. The essential oils were screened for mosquito larvicidal activity against Aedes aegypti and Culex quinquefasciatus, for molluscicidal activity against Gyraulus convexiusculus and Pomacea canaliculata, and for inhibition of acetylcholinesterase (AChE). The essential oils showed moderate to good pesticidal activities against these organisms. However, the oils also showed pronounced lethality to a non-target water bug, Diplonychus rusticus.