Larvicidal activity of Amyris balsamifera, Daucus carota and Pogostemon cablin essential oils and their components against Culex pipiens pallens

Larvicidal activities of Amyris balsamifera, Daucus carota, and Pogostemon cablin essential oils were tested against Culex pipiens pallens. All three oils showed 100% larvicidal activity against C. pipiens pallens at 0.1 mg/mL. Among the tested oils, the larvicidal activity of D. carota oil was the strongest followed by P. cablin and A. balsamifera. Four active compounds such as β-eudesmol, elemol, patchoulol, and carotol were isolated from the three oils by open column chromatography. These compounds showed > 90% mortality against C. pipiens pallens at 0.1 mg/mL. In acute toxicity testing of the water flea, Daphnia magna, P. cablin oil was the most toxic followed by A. balsamifera, and D. carota. Among the isolated compounds, carotol was the most toxic to water fleas. The residues of P. cablin, A. balsamifera, and D. carota in water were 67.8%, 59.5%, and 51.2% at 2 days after treatment, respectively. High concentrations of elemol and patchoulol were detected 2 days after treatment compared to those of β-eudesmol and elemol. Whole oils and compounds tested were detected at < 50% after 7 days in water.

Graphical abstractChemical structures of isolated compounds from Amyris balsamifera, Daucus carota and Pogostemon cablin essential oils.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Plant essential oils showed strong insecticidal activity against mosquito larvae. ► Four active compounds were isolated. ► Oils and isolated compounds were detected less than 50% at 7 days in water.