Essential Oils from Vietnamese Asteraceae for Environmentally Friendly Control of Mosquitoes.

Mosquitoes, in addition to being a biting nuisance, are vectors of several pathogenic viruses and parasites. As a continuation of our work identifying abundant and/or invasive plant species in Vietnam for use as ecologically friendly pesticidal agents, we obtained the essential oils of , , , , and ; analyzed the essential oils using gas chromatographic techniques; and screened the essential oils for mosquito larvicidal activity against and . The most active larvicidal essential oils were , which was rich in thymohydroquinone dimethyl ether (29.4%), ()-β-caryophyllene (19.7%), α-pinene (8.8%), germacrene D (7.8%), and α-humulene (4.3%), (24-h LC 23.4 and 29.1 μg/mL) on and , respectively, and , dominated by 1-undecene (41.9%) and germacrene D (11.0%), (24-h LC 30.1 and 29.6 μg/mL) on the two mosquito species. The essential oils of and were also active against mosquito larvae. Notably, , , and essential oils were not toxic to the non-target water bug, . However, essential oil showed insecticidal activity (24-h LC 48.1 μg/mL) on . Based on these results, , , and essential oils appear promising for further investigations.